Chapter II: Preface (1)

The first edition of Gray's Manual was published in 1848. It was to a great extent rewritten and its range extended in 1856, and it was again largely rewritten in 1867. The great advances that have since been made in systematic botany and in the knowledge of our flora have for several years past made another revision desirable, which Dr. Gray before his death was purposing to undertake.

The present editors, acting to the best of their ability in his stead, have endeavored throughout to follow his methods and views. The original plan, so long retained by Dr. Gray and so generally approved, has been closely adhered to, the characters and descriptions of the last edition have been left essentially unchanged so far as possible, and in the numerous alterations and additions that have been considered necessary or advisable, his conclusions and principles have governed in every matter of importance, so far as they could be known. The effort especially has been to maintain that high standard of excellence which has always made the Manual an authority among botanists.

In the treatment of the genera and species, Gray's Synoptical Flora has been made the basis in the revision of the Gamopetalous Orders, and the manuscript in continuation of that work, so far as prepared, for the Polypetalous Orders which precede _Leguminosae_ (excepting _Nuphar_, the _Cruciferae, Caryophyllaceae, Vitis_, and the small Orders numbered 18, 22, 23, 25-27, and 29). The genus _Salix_ has been rewritten for this edition by M. S. BEBB, Esq., the genus _Carex_ by Prof. L. H. BAILEY, and the Ferns and allied orders by Prof. D. C. EATON. For the rest, all known available sources of information have been made use of, and much willing help has been received from botanists in all parts of our territory.

The increasing interest that is taken in the study of the Cellular Cryptogams, and the desire to encourage it, have led to the inclusion again of the Hepaticae, which were omitted in the last edition. These have been prepared through the kindness of Prof. L. M. UNDERWOOD, though the limits of the volume have necessitated somewhat briefer descriptions than he considered desirable. The three fine plates illustrating the genera of these Orders, which were used in the early editions, are also added, with a supplementary one, as well as an additional one in illustration of the Grasses, thus increasing the number of plates to twenty-five. A Glossary of botanical terms is appended, to meet an expressed need of those who use the Manual alone, and a Synopsis of the Orders in their sequence is given, to contrast more clearly their characters, and to show the general principles which have determined their present arrangement. This should be a useful adjunct to the more artificially arranged Analytical Key.

GEOGRAPHICAL LIMITS, AND DISTRIBUTION.--The southern limit of the territory covered by the present work is the same as in the later previous editions, viz. the southern boundary of Virginia and Kentucky. This coincides better than any other geographical line with the natural division between the cooler-temperate and the warm-temperate vegetation of the Atlantic States. The rapid increase of population west of the Mississippi River, and the growing need of a Manual covering the flora of that section, have seemed a sufficient reason for the extension of the limits of the work westward to the 100th meridian, thus connecting with the _Manual of the Flora of the Rocky Mountain Region_ by Prof. Coulter. These limits, as well as that upon the north, have been in general strictly observed, very few species being admitted that are not known with some degree of certainty to occur within them. The extreme western flora is no doubt imperfectly represented.

The distribution of the individual species is indicated somewhat more definitely than heretofore in many cases, so far as it could be satisfactorily ascertained. The extralimital range is also sometimes given, but the terms "northward," "southward," and "westward" are more frequently employed, signifying an indefinite range in those directions beyond the limits of the Manual. Where no definite habitat is specified, the species may be understood as found more or less generally throughout the whole area, or at least to near the western limits.

NOMENCLATURE, ACCENTUATION OF NAMES, etc.--In case of question respecting the proper name to be adopted for any species, Dr. Gray's known and expressed views have been followed, it is believed, throughout the work. While reasonable regard has been paid to the claims of priority, the purpose has been to avoid unnecessary changes, in the belief that such changes are in most cases an unmitigated evil. Synonyms are rarely given except where changes have been made. As a guide to correct pronunciation, the long sound of the accented vowel (modified often in personal names) is indicated, as heretofore, by the grave accent (`), and the short sound by the acute ('). In regard to the derivations of generic names, many valuable suggestions have been due to W. R. Gerard, Esq., of New York.

PROMINENT CHARACTERS are indicated by the use of _Italic type_ for the leading distinctions of the Orders, and generally in the specific descriptions for those points by which two or more nearly allied species may be most readily distinguished. The ready discrimination of the genera is provided for by a Synopsis of their leading characters under each order. Whenever a genus comprises several species, pains have been taken to render important differences conspicuous by proper grouping, and when needed by a series of subordinate divisions and subdivisions. The headings of these various groups are to be considered as belonging to and forming a part of the specific characters of the several species under them,--a fact which the student should always bear in mind.

ARRANGEMENT OF THE ORDERS.--The Natural Orders are disposed in very close accordance with the method followed by Bentham and Hooker in the _Genera Plantarum_, the principles of which are concisely shown in the Synopsis of Orders which precedes the Analytical Key. The _Gymnospermae_ are retained as a Subclass following the Angiospermous Dicotyledons, with which they have an obvious relationship, in preference to placing them, as some authorities would do, next before the Pteridophytes, to which their affinity, if no less certain, is nevertheless obscure. A more natural arrangement than either would be the withdrawal of the Endogens, placing them at the beginning, in perhaps an inverse order.

ANALYTICAL KEY TO THE ORDERS.--As stated in Dr. Gray's Preface to the last edition, this is designed to enable the student to refer readily to its proper Order any of our plants, upon taking the pains to ascertain the structure of its flowers, and sometimes of the fruit, and by following out a series of easy steps in the analysis. It is founded upon the most obvious distinctions which will answer the purpose, and is so contrived as to provide for all or nearly all exceptional instances and variant cases. Referring to the Order which the Key leads him to, the student will find its most distinctive points brought together and printed in Italics in the first sentence of the ordinal description, and thus can verify his results. The Synopsis which follows will then lead him to the genus, to be verified in turn by the full generic description in its place; and the progress thence to the species is facilitated, when there are several to choose from, by the arrangement under divisions and subdivisions, as already explained.

It will be seen that the Key directs the inquirer to ascertain, first, the Class of the plant under consideration,--which, even without the seeds, is revealed at once by the plan of the stem, as seen in a cross-section, and usually by the veining of the leaves, and is commonly confirmed by the numerical plan of the flower;--then, if of the first Class, the Subclass is at once determined by the pistil, whether of the ordinary kind, or an open scale bearing naked ovules. If the former, then the choice between the three Divisions is determined by the presence or absence of the petals, and whether separate or united. Each Division is subdivided by equally obvious characters, and, finally, a series of successively subordinated propositions,--each set more indented upon the page than the preceding,--leads to the name of the Order sought for, followed by the number of the page upon which it is described in the body of the work.

The book is now submitted to those for whose benefit it has been prepared, in the trust that its shortcomings will meet with friendly indulgence, and with the earnest request that information be kindly given of any corrections or additions that may appear to be necessary.

SERENO WATSON.
CAMBRIDGE, MASS., Dec. 26, 1889.

SYNOPSIS OF THE ORDERS OF PLANT

DESCRIBED IN THIS WORK.

SERIES I. PHAENOGAMOUS OR FLOWERING PLANTS: those producing real flowers and seeds.

CLASS I. DICOTYLEDONOUS OR EXOGENOUS PLANTS.

Stems formed of bark, wood, and pith; the wood forming a zone between the other two, and increasing, when the stem continues from year to year, by the annual addition of a new layer to the outside, next the bark. Leaves netted-veined. Embryo with a pair of opposite cotyledons, or in Subclass II. often three or more in a whorl. Parts of the flower mostly in fours or fives.

SUBCLASS I. ANGIOSPERMAE. Pistil consisting of a closed ovary which contains the ovules and becomes the fruit. Cotyledons only two.

DIVISION I. POLYPETALOUS: the calyx and corolla both present; the latter of _separate_ petals. (Apetalous flowers occur in various Orders, as noted under the subdivisions.)

[A.] THALAMIFLORAE. Stamens and petals hypogynous (free both from the calyx and from the superior ovary), upon a usually narrow receptacle (not glandular nor discoid, except in Reseda, sometimes stipe-like). (Stamens and petals upon the partly inferior ovary in some Nymphaeaceae.) Apetalous flowers occur in the Ranunculaceae and Caryophyllaceae.

[*] 1. Carpels solitary or distinct (or coherent in Magnoliaceae); sepals and petals deciduous (except in Nymphaeaceae); leaves alternate or radical, without stipules (sometimes opposite or whorled and rarely stipular in Ranunculaceae); embryo (except in Nelumbo) small, in fleshy albumen.

1. Ranunculaceae (p. 34). Sepals (3 or more), petals (as many, in regular flowers, or none), stamens (usually many), and carpels (1--many) all distinct. Fruit achenes, follicles, or berries. Mostly herbs.

2. Magnoliaceae (p. 49). Sepals and petals colored alike, in three or more rows of three, imbricate. Fruit cone-like, formed of the numerous cohering pistils. Trees.

3. Anonaceae (p. 50). Sepals (3) and petals (6, in two rows) valvate. Fruit pulpy. Shrubs or small trees.

4. Menispermaceae (p. 51). Sepals and petals in twos or threes, imbricate. Pistils becoming 1-seeded drupes. Dioecious woody climbers, with palmate or peltate leaves.

5. Berberidaceae (p. 52). Sepals and petals imbricate, each in two rows of three (rarely in twos or fours). Stamens opposite the petals. Pistil solitary, becoming a berry or pod. Shrubs or low herbs.

6. Nymphaeaceae, in part (p. 54). Sepals and petals each 3, or many in several rows. Pistils becoming coriaceous and indehiscent. Aquatics; floating leaves peltate.

[*] 2. Carpels (2 or more) united into a compound ovary with parietal, often nerve-like placentae (or the seeds covering the inner surface in Nymphaeaceae, and the placentae axile in Sarraceniaceae). Herbs (some Cistaceae somewhat shrubby).

[+] Fruit 5--many-celled; calyx or whole perianth persistent; embryo small, at the base of fleshy albumen.

6. Nymphaeaceae proper (p. 54). Sepals 2--6. Petals and stamens numerous, on a thick hypogynous receptacle or inserted upon the ovary. Capsule 8--30-celled. Aquatics, with peltate or cordate leaves.

7. Sarraceniaceae (p. 57). Sepals and petals 5. Capsule 5-celled. Marsh plants, with pitcher-shaped leaves.

[+][+] Fruit 1-celled, or spuriously 2--more-celled by partitions connecting the placentae.

[++] Embryo minute at the base of fleshy albumen; perianth deciduous; sepals 2.

8. Papaveraceae (p. 57.) Flowers regular. Sepals fugacious. Petals 4--12. Stamens and seeds numerous. Capsule 2--several-valved. Juice milky or colored.

9. Fumariaceae (p. 59.) Flowers irregular. Petals 4, in dissimilar pairs. Stamens 6, diadelphous. Fruit 2-valved (indehiscent and 1-seeded in Fumaria). Juice watery; leaves dissected.

[++][++] Albumen none; embryo curved or folded; perianth deciduous (sepals persistent in Resedaceae).

10. Cruciferae (p. 61). Sepals and petals 4. Stamens mostly 6, tetradynamous (two inserted lower and shorter). Pod 2-celled by a transverse partition, 2-valved, or sometimes indehiscent or transversely jointed. Bracts and stipules none.

11. Capparidaceae (p. 74). Sepals and petals 4. Stamens 6 or more, nearly equal. Pod 1-celled, 2-valved. Embryo coiled. Leaves often palmately divided; bracts and stipules often present.

12. Resedaceae (p. 75). Sepals and petals 4--7, irregular. Stamens indefinite on an hypogynous disk, not covered in the bud. Pod 1-celled, 3--6-lobed, opening at the top.

[++][++][++] Embryo rather large in fleshy albumen; placentae on the middle of the valves; calyx persistent.

13. Cistaceae (p. 76). Flowers regular; sepals and petals 5, the two outer sepals minute. Stamens indefinite. Pod 1-celled, 3--5-valved. Ovules orthotropous. Embryo curved. Leaves entire, the lower often opposite.

14. Violaceae (p. 78). Flowers irregular; sepals and petals 5. Stamens 5, with connivent introrse anthers. Style clavate. Pod 1-celled, 3-valved. Ovules anatropous. Embryo straight. Stipules present.

[*] 3. Ovary compound, 1-celled, with central placentae; embryo curved around mealy albumen (except in Dianthus); leaves entire; stipules mostly none.

15. Caryophyllaceae (p. 82). Sepals (5, rarely 4) distinct or united, persistent. Petals as many, rarely none. Stamens as many or twice as many, rarely fewer. Styles 2--5. Leaves opposite.

16. Portulacaceae (p. 90). Sepals 2. Petals 5. Stamens 5--20. Capsule 3-valved or circumscissile. Fleshy herbs; leaves mostly alternate.

[*] 4. Calyx imbricate; stamens as many or twice as many as the petals or often indefinite; ovary compound, 1-celled with parietal placentae or several-celled with the placentae united in the axis; embryo straight or slightly curved; albumen none or scanty.

17. Elatinaceae (p. 91). Small marsh annuals, with opposite leaves, membranous stipules, minute axillary flowers, few stamens, and pod 2--5-celled.

18. Hypericaceae (p. 92). Herbs or shrubs, with opposite entire dotted leaves and no stipules. Flowers cymose or panicled. Stamens few or many, usually in 3 or more clusters. Pod 1-celled or 3--5-celled.

19. Ternstroemiaceae (p. 95). Trees or shrubs, with alternate leaves and no stipules. Flowers large, axillary, solitary. Stamens numerous, more or less united together and with the base of the petals. Pod 3--5-celled.

[*] 5. Calyx valvate; stamens numerous, usually more or less united together and with the base of the petals; ovary 3--many-celled with the placentae united in the axis (becoming 1-celled and 1-seeded in Tilia).

20. Malvaceae (p. 96). Stamens monadelphous; anthers 1-celled. Calyx persistent. Seeds kidney-shaped, with curved embryo and little albumen. Herbs or shrubs, with alternate palmately veined stipular leaves.

21. Tiliaceae (p. 101). Stamens polyadelphous or nearly distinct; anthers 2-celled. Calyx deciduous. Embryo nearly straight. Trees, with alternate leaves and deciduous stipules.

[B.] DISCIFLORAE. Stamens as many as the petals or twice as many or fewer, inserted upon or at the outer or inner base of a more or less tumid hypogynous or perigynous disk, which is cushion-like or annular or divided into glands, sometimes obscure or minute (or none in Linum, Ilex, some Geraniaceae and Polygala); ovary superior (or half-inferior in some Rhamnaceae); sepals more usually distinct. Petals wanting in some Rutaceae, Rhamnaceae, and Sapindaceae.

[*] 1. Ovules (mostly 1 or 2 in each cell) pendulous, with the rhaphe toward the axis of the ovary; disk often reduced to glands alternate with the petals or none; ovary often lobed or the carpels nearly distinct.

22. Linaceae (p. 101). Flowers regular, usually 5-merous. Capsule not lobed, mostly 5-valved, spuriously 10-celled, 10-seeded. Stamens united at base. Disk none or 5 minute glands. Herbs, with entire alternate or opposite leaves; stipules gland-like or none.

23. Geraniaceae (p. 102). Flowers regular or irregular, 5-merous or 3-merous as to the stamens and pistils. Ovary 3--5-lobed, the cells 1--few-ovuled, and axis persistent. Disk of 5 glands or none. Herbs, with often lobed or divided mostly alternate leaves, with or without stipules.

24. Rutaceae (p. 106). Flowers mostly regular, 3--5-merous, dioecious or polygamous in our genera. Ovary 2--5-lobed or the carpels nearly distinct, upon a glandular disk; cells 2-ovuled. Mostly shrubs or trees, with glandular-punctate compound leaves, without stipules.

[*] 2. Ovules (1 or 2) pendulous, the rhaphe away from the axis; disk none and ovary not lobed.

25. Ilicineae (p. 107). Flowers small, dioeciously polygamous, axillary, 4--8-merous. Fruit a 4--8-seeded berry-like drupe. Shrubs or trees, with simple alternate leaves and no stipules.

[*] 3. Ovules (1 or 2 in each cell) erect, the rhaphe toward the axis; disk fleshy, covering the base of the calyx; stamens as many as the petals, at the margin of the disk; flowers perfect or polygamo-dioecious; albumen fleshy; shrubs or trees, with simple leaves (compound in some Vitaceae).

26. Celastraceae (p. 109). Sepals and petals imbricated, the stamens alternate with the petals. Fruit 2--5-celled; seeds arilled.

27. Rhamnaceae (p. 111). Calyx valvate. Petals small or none. Stamens alternate with the sepals. Fruit 2--5-celled; seeds solitary, not arilled.

28. Vitaceae (p. 112). Calyx minute. Stamens opposite the valvate caducous petals. Climbing by tendrils opposite the alternate leaves.

[*] 4. Ovules (1 or 2) ascending or horizontal, or pendulous from a basal funicle; fleshy disk entire or lobed; stamens 5--10; shrubs or trees, with compound leaves (simple in Acer) and mostly polygamo-dioecious and often irregular flowers; petals imbricate (sometimes none in Sapindaceae).

29. Sapindaceae (p. 115). Flowers mostly unsymmetrical or irregular. Ovary 2--3-celled and -lobed.

30. Anacardiaceae (p. 118). Flowers regular, 5-androus. Ovary 1-celled, becoming a small dry drupe. Leaves alternate; juice milky or resinous.

[*] 5. Ovules solitary, pendulous from the summit of the 2-celled ovary; disk none; flowers irregular (subpapilionaceous), hypogynous; stamens monadelphous or diadelphous; anthers 1-celled, opening by an apical pore.

31. Polygalaceae (p. 120). Herbs, with perfect flowers and alternate or opposite or whorled entire leaves. Stamens 6--8. Seed carunculate.

[C.] CALYCIFLORAE. Sepals rarely distinct; disk adnate to the base of the calyx, rarely tumid or conspicuous; petals and stamens on the calyx, perigynous or epigynous, the ovary being often inferior (hypogynous in Drosera and Parnassia, nearly so in some Leguminosae and Crassulaceae). Apetalous flowers in Orders 33, 35, 36, 38, 39, 41, 42, 47, and 50.

[*] 1. Ovary usually superior, the pistils solitary, or several and distinct (sometimes more or less united but at least the styles distinct except in some Saxifragaceae).

32. Leguminosae (p. 122). Flowers papilionaceous or regular. Stamens usually 10, and mostly monadelphous or diadelphous. Pistil one, free, becoming a legume; style terminal. Albumen none. Leaves mostly compound, alternate, stipular.

33. Rosaceae (p. 150). Flowers regular, with usually numerous distinct stamens, and 1--many pistils, distinct or (in Pomeae) united and combined with the calyx-tube; style often lateral or basal. Calyx-lobes and petals mostly 5. Ovules mostly 1 or 2. Albumen mostly none. Trees, shrubs, or herbs; leaves usually alternate and stipulate, simple or compound.

34. Calycanthaceae (p. 167). Calyx-lobes, petals, and stamens indefinite. Pistils numerous, becoming achenes in a hollow receptacle. Albumen none. Aromatic shrubs, with opposite entire leaves and no stipules.

35. Saxifragaceae (p. 168). Flowers regular, with 5--10 stamens (numerous in Philadelphus), few (mostly 2) more or less united, free or partially adnate carpels, and few--many ovules on axile or sometimes parietal placentae. Seeds albuminous. Herbs or shrubs, with opposite or alternate leaves, with or without stipules.

36. Crassulaceae (p. 170). Mostly fleshy herbs, with symmetrical flowers, the usually distinct many-seeded carpels as many as the sepals. Seeds albuminous. Leaves alternate or opposite or whorled; stipules none.

37. Droseraceae (p. 178). Glandular-haired scapose marsh herbs, with regular 5-merous hypogynous flowers. Capsule 1-celled, with 3--5 many-seeded parietal placentae. Anthers extrorse. Leaves circinate in vernation.

38. Hamamelideae (p. 179). Shrubs or trees; flowers often polygamo-monoecious, in clusters, heads, or spikes; petals often none. Seeds 2 or more, bony, in a 2-beaked woody pod opening above, the base adnate to the calyx-tube. Stamens few or many. Leaves alternate, simple.

39. Halorageae (p. 180). Aquatic or marsh herbs; flowers perfect or polygamo-dioecious, small, axillary or spicate; petals often none. Stamens 1--8. Ovary inferior, the calyx-limb obsolete or very short. Fruit small, indehiscent, 1--4-celled, 1--4-seeded. Leaves alternate or opposite, the submersed often dissected.

[*] 2. Ovary inferior (except in Lythraceae), 1--several-celled; style entire; flowers perfect, regular or nearly so, mostly 4-merous; herbs, with simple and mostly entire leaves without stipules.

40. Melastomaceae (p. 183). Calyx open. Stamens definite; anthers opening by an apical pore. Leaves opposite, 3--7-nerved; flowers cymose.

41. Lythraceae (p. 184). Calyx-lobes valvate. Pod free, but enclosed in the calyx, membranous, 1--4-celled, many-seeded with axile placentae. Leaves mostly opposite; flowers axillary or whorled; petals crumpled, or none.

42. Onagraceae (p. 186). Calyx-lobes valvate. Ovary 1--4-celled, the cells 1--many-ovuled. Stamens 2, 4, or 8. Petals 2 or 4, convolute, or none. Leaves opposite or alternate.

[*] 3. Ovary inferior (except in Passifloraceae and Ficoideae), 1-celled with parietal placentae or several-celled by the intrusion of the placentae; flowers regular, perfect or unisexual; styles free or united; herbs.

[+] Embryo straight; cotyledons foliaceous; leaves alternate, often lobed.

43. Loasaceae (p. 193). Flowers perfect. Stamens indefinite. Style entire or 2--3-cleft. Capsule 1-celled, with 2 or 3 many-seeded placentae. Pubescence of hooked hairs.

44. Passifloraceae (p. 194). Climbing by tendrils. Flowers perfect. Stamens 5, monadelphous. Ovary stalked, superior, becoming a 1-celled many-seeded berry with 3 or 4 placentae. Styles 3, clavate.

45. Cucurbitaceae (p. 194). Tendril-bearing vines, with dioecious or monoecious flowers. Corolla 5-lobed, often confluent with the calyx. Stamens 3 or 5, usually more or less united and the anthers often tortuous. Fruit fleshy or membranous, 1--5-celled, the placentae often produced to the axis and revolute. Seeds exalbuminous.

[+][+] Embryo curved or coiled about central albumen; leaves entire.

46. Cactaceae (p. 196). Fleshy and mostly leafless prickly plants, with solitary sessile perfect flowers. Calyx-lobes and petals indefinite, imbricated, the numerous stamens on the tube. Fruit a 1-celled many-seeded berry.

47. Ficoideae (p. 198). Calyx-lobes or sepals 5 and petals none in our genera. Capsule 3--5-celled with axile placentae, loculicidal or circumscissile, many-seeded. Often fleshy; leaves mostly opposite or verticillate.

[*] 4. Flowers small, regular, perfect or polygamous; calyx-limb minute or obsolete; ovary inferior, 2--several-celled, with solitary pendulous ovules; petals and stamens mostly 4 or 5, on the margin of an epigynous disk surrounding the styles; albumen copious.

48. Umbelliferae (p. 198). Flowers in umbels or heads. Petals (inflexed) and stamens 5. Styles 2. Fruit of 2 dry seed-like carpels, the pericarp usually with oil-tubes. Herbs, with alternate mostly compound leaves.

49. Araliaceae (p. 212). Flowers mostly in umbels and nearly as in Umbelliferae; petals not inflexed and styles 2 or more. Fruit a 2--several-celled drupe. Herbs or shrubs, with alternate mostly compound leaves.

50. Cornaceae (p. 213). Flowers not in umbels; petals (valvate, or none) and stamens 4 or 5. Style 1. Fruit a 1--2-seeded drupe. Trees, shrubs, or rarely herbs, with opposite or alternate simple and mostly entire leaves.

DIVISION II. GAMOPETALOUS: calyx and corolla both present, the latter of united petals (excepting some Ericaceae, Styracaceae, and Oleaceae, Galax, Statice, and Lysimachia). Apetalous flowers occur in Glaux and some Oleaceae. Stipules present only in Rubiaceae and Loganiaceae, or rarely in Caprifoliaceae.

[*] 1. Ovary inferior; stamens borne upon the corolla, alternate with its lobes.

[+] Stamens distinct; leaves opposite or whorled; seed albuminous except in Valerianaceae.

51. Caprifoliaceae (p. 216). Corolla mostly 5-lobed, regular or irregular, the stamens as many (one fewer in Linnaea, doubled in Adoxa). Ovary 1--several-celled; fruit a berry, drupe, or pod, 1--several-seeded. Shrubs or herbs; leaves opposite, rarely stipular, not turning black in drying.

52. Rubiaceae (p. 222). Flowers regular, 4--5-merous, the corolla mostly valvate. Ovary 2--4-celled. Herbs or shrubs; leaves simple, entire, opposite with stipules, or verticillate, usually turning black in drying.

53. Valerianaceae (p. 228). Stamens (1--4) fewer than the lobes of the somewhat irregular corolla. Ovary with two abortive or empty cells and one containing a suspended ovule. Fruit dry and indehiscent. Herbs.

54. Dipsaceae (p. 229). Flowers mostly 4-merous and with 4 (rarely 2) stamens, involucellate in involucrate heads; corolla-lobes imbricate. Ovary simple, 1-celled, with a suspended ovule. Herbs.

[+][+] Anthers connate into a tube.

55. Compositae (p. 230). Stamens as many as the valvate corolla-lobes. Ovary with a solitary erect ovule, becoming an achene. Albumen none. Calyx-limb reduced to a pappus or none. Flowers in involucrate heads.

[*] 2. Ovary inferior (or superior in most Ericaceae and in Diapensiaceae); stamens free from the corolla or nearly so (adnate in some Diapensiaceae), as many as the lobes and alternate with them, or twice as many; leaves alternate (opposite in some Ericaceae); style 1.

[+] Juice milky; capsule 2--5-celled, many-seeded; herbs.

56. Lobeliaceae (p. 305). Corolla irregular, 5-lobed. Stamens united, at least by the anthers. Capsule 2-celled or with two placentae.

57. Campanulaceae (p. 307). Corolla regular, 5-lobed, valvate. Stamens usually distinct. Capsule 2--several-celled.

[+][+] Juice not milky nor acrid; capsule 3--10-celled.

58. Ericaceae (p. 309). Flowers mostly regular, 4--5-merous. Stamens distinct, more usually twice as many as the corolla-lobes or petals. Ovary inferior or superior. Herbs or shrubs.

59. Diapensiaceae (p. 326). Flowers regular. Stamens 5, on the corolla, or monadelphous with 5 petaloid staminodia. Ovary superior, 3-celled.

[*] 3. Ovary superior; stamens as many as the corolla-lobes and opposite them.

60. Plumbaginaceae (p. 327). Stamens 5, on the base of the petals. Styles 5. Fruit an achene or 1-seeded utricle. Herbs; leaves radical.

61. Primulaceae (p. 328). Stamens 4--8, perigynous. Style 1. Fruit a capsule with several seeds on a central placenta. Herbs; leaves radical or opposite or alternate.

62. Sapotaceae (p. 332). Flowers small, 4--5-merous. Style 1. Ovary few--several-celled; fruit fleshy, bearing a single bony-coated seed. Shrubs or trees, with milky juice and alternate entire leaves.

[*] 4. Ovary superior or more or less adnate to the calyx, few--several-celled, the cells 1-ovuled; stamens twice as many as the corolla-lobes or more; trees or shrubs, with alternate leaves.

63. Ebenaceae (p. 333). Flowers dioecious or polygamous. Stamens on the corolla. Ovary superior. Styles distinct. Fruit fleshy, few-seeded.

64. Styracaceae (p. 333). Flowers perfect. Stamens subhypogynous. Ovary more or less inferior. Style 1. Fruit dry or nearly so, 1--4-seeded.

[*] 5. Ovary superior, of two carpels (sometimes by division apparently 4-carpellary, sometimes of 3--5 in Polemoniaceae, Convolvulaceae, and Solanaceae); stamens on the corolla (except in apetalous Oleaceae), alternate with its lobes, as many or fewer.

[+] Corolla not scarious and nerveless.

[++] Corolla none, or regular and 4-cleft or -parted, the stamens fewer than its lobes; style 1; seeds 1--3.

65. Oleaceae (p. 335). Trees or shrubs, with opposite and pinnate or simple leaves. Flowers perfect or polygamo-dioecious. Stamens mostly 2, alternate with the usually 2-ovuled carpels.

[++][++] Corolla regular, its lobes 4--5 or rarely more; stamens as many.

[=] Ovaries 2, becoming follicles; stigmas and sometimes the styles united; herbs with milky juice, perfect 5-merous flowers, and simple entire leaves.

66. Apocynaceae (p. 337). Stamens distinct or the anthers merely connivent, with ordinary pollen. Style 1.

67. Asclepiadaceae (p. 338). Stamens monadelphous, the anthers permanently attached to a large stigmatic body; pollen mostly in waxy masses. Styles distinct below the stigma.

[=][=] Ovary compound (ovaries two in Dichondra), with 2 or 3 (rarely 4 or 5) cells or placentae; stamens distinct; mostly herbs.

[a.] Leaves opposite; corolla-lobes 4 or 5 or more.

68. Loganiaceae (p. 345). Leaves entire, with stipules or a stipular line joining their bases. Capsule 2-celled, few--many-seeded. Herbs or woody twiners (our species).

69. Gentianaceae (p. 346). Glabrous herbs; leaves entire, sessile and simple (except in Menyanthes). Capsule 1-celled with 2 parietal placentae or the whole inner surface ovuliferous, many-seeded.

[b.] Leaves alternate (sometimes opposite in Polemoniaceae and Hydrophyllaceae); corolla-lobes always 5 in our species.

70. Polemoniaceae (p. 354). Capsule usually 3-celled, loculicidal; seeds 1--many in each cell on the stout placental axis. Style 3-cleft or -lobed. Leaves opposite or alternate, simple or compound.

71. Hydrophyllaceae (p. 357). Leaves often lobed or divided, and the inflorescence frequently scorpioid. Style 2-parted or 2-lobed. Capsule 1-celled, 2-valved with two parietal or introflexed placentae, or sometimes 2-celled. Seeds 2 or more on each placenta.

72. Borraginaceae (p. 360). Leaves mostly entire and plants often rough-hispid; inflorescence commonly scorpioid. Style 1. Ovary 4-ovulate, usually 4-lobed and maturing as 4 separate or separable nutlets, or not lobed, 2--4-celled and separating when ripe into 2 or 4 nutlets.

73. Convolvulaceae (p. 367). Usually twining or trailing; flowers on axillary peduncles or cymose-glomerate. Corolla 5-lobed or 5-plaited, twisted in the bud. Styles 1 or 2. Ovary 2- (sometimes 3- or spuriously 4-) celled, becoming a globular 4--6-seeded capsule (or ovaries two and distinct in Dichondra). Cotyledons broad-foliaceous.

74. Solanaceae (p. 373). Style 1. Ovary 2-celled (rarely 3--5-celled), with numerous ovules on axillary placentae, becoming a pod or berry. Cotyledons narrow.

[++][++][++] Corolla more or less bilabiately irregular (sometimes nearly regular), 5-lobed. Fertile stamens 4 and didynamous, or 2. Style 1. Ovary always of two carpels.

[a.] Ovules several or many.

75. Scrophulariaceae (p. 377). Capsule 2-celled, with central placentae. Seeds small, usually numerous. Herbs; leaves alternate or opposite.

76. Orobanchaceae (p. 393). Root-parasites with no green foliage. Capsule 1-celled, with 2 simple or double parietal placentae. Seeds many.

77. Lentibulariaceae (p. 395). Aquatic or marsh herbs, with scapes or scape-like peduncles, sometimes nearly leafless. Corolla personate and spurred. Capsule globular, 1-celled; placentae central, free, many-seeded.

78. Bignoniaceae (p. 398). Large-flowered trees or often climbing shrubs, with usually opposite simple or compound leaves. Capsule 2-celled by a partition between the 2 parietal placentae. Seeds numerous, large, mostly winged.

79. Pedaliaceae (p. 399). Herbs, with opposite simple leaves. Ovary 1-celled with two bilamellar parietal placentae, or 2--4-celled by their union, becoming drupaceous or capsular. Seeds few or many, wingless.

80. Acanthaceae (p. 399). Herbs, with opposite simple leaves. Capsule 2-celled, loculicidal, with each axile placenta bearing 2--10 flattish seeds.

[b.] Cells of the ovary 1--2-ovuled; herbs or low shrubs, with opposite leaves.

81. Verbenaceae (p. 401). Ovary 2--4-celled, not lobed, the dry or drupaceous fruit separating into 2 or 4 1-seeded nutlets (fruit 1-celled and 1-seeded in Phryma). Style terminal.

82. Labiatae (p. 403). Ovary deeply 4-lobed around the style, the lobes becoming dry seed-like nutlets. Stems square; aromatic.

[+][+] Corolla scarious and nerveless; flowers regular, 4-merous; style 1.

83. Plantaginaceae (p. 422). Scapose herbs, with perfect or polygamo-dioecious or monoecious flowers in 1--many-flowered spikes. Fruit a circumscissile 2-celled capsule, with one or more peltate seeds in each cell, or an achene.

DIVISION III. APETALOUS EXOGENS. The corolla wanting (except in some Euphorbiaceae), and sometimes also the calyx.

[*] 1. Ovary superior (though sometimes enclosed within the calyx), 1-celled with a solitary basal ovule (several-celled in Phytolaccaceae); embryo coiled or curved (nearly straight in Polygonaceae) in or about mealy albumen (albumen none in some Chenopodiaceae); herbs.

[+] Fruit the hardened or membranous closed base of the corolla-like perianth enclosing a utricle.

84. Nyctaginaceae (p. 425). Perianth tubular or funnelform. Stamens hypogynous. Fruit ribbed or winged. Leaves opposite; stipules none.

[+][+] Fruit a utricle; perianth mostly persistent, small, 4--5-lobed or -parted, or none.

85. Illecebraceae (p. 426). Perianth herbaceous. Stamens perigynous. Leaves opposite; stipules scarious (none in Scleranthus).

86. Amarantaceae (p. 427). Flowers sessile, bracteate, the bracts (usually 3) more or less dry and scarious, as well as the 3--5 distinct sepals. Stamens 1--5, hypogynous. Utricle indehiscent or circumscissile. Embryo annular. Leaves mostly alternate, entire; stipules none.

87. Chenopodiaceae (p. 430). Flowers sessile, not scarious-bracteate. Sepals greenish or succulent, 5 or fewer, or none. Stamens 5 or fewer, perigynous or hypogynous. Embryo annular or spiral or conduplicate. Leaves alternate; stipules none.

[+][+][+] Ovary of several 1-ovuled carpels, in fruit a berry (in our genera).

88. Phytolaccaceae (p. 435). Sepals 4--5, petaloid or herbaceous. Stamens 5--30, hypogynous. Carpels 5--12. Embryo annular. Leaves alternate, entire; stipules none.

[+][+][+][+] Fruit a triangular or lenticular achene.

89. Polygonaceae (p. 436). Flowers on jointed pedicels. Calyx 3--6-lobed or -parted, more or less corolla-like. Stamens 4--12, on the calyx. Embryo nearly straight. Leaves alternate, with sheathing stipules or none.

[*] 2. Ovary compound, the cells many-ovuled (or 1-ovuled in Piperaceae); embryo minute in copious albumen; flowers perfect.

90. Podostemaceae (p. 444). Aquatic, with the aspect of sea-weeds or mosses, with minute naked flowers from a spathe-like involucre. Ovary superior; pod 2--3-celled.

91. Aristolochiaceae (p. 444). Terrestrial herbs or climbing shrubs. Calyx valvate, adnate at least at base to the 6-celled many-seeded ovary. Stamens 6--12, more or less united with the style. Leaves alternate, mostly cordate; stipules none.

92. Piperaceae (Sec. Saurureae), (p. 446). Marsh herb (our species). Perianth none. Carpels 3--4, distinct, with usually a single ascending seed. Leaves alternate, entire.

[*] 3. Ovary superior, simple, 1-celled, 1-ovuled, forming a berry or drupe; trees or shrubs, with mostly entire leaves and no stipules.

93. Lauraceae (p. 446). Flowers perfect or dioecious. Sepals 4 or 6, in 2 rows. Stamens 9--12; anthers opening by 2 or 4 uplifted valves. Seed suspended; albumen none. Aromatic; leaves alternate.

94. Thymelaeaceae (p. 448). Flowers perfect. Calyx corolla-like, 4--5-cleft. Stamens twice as many. Seed suspended, with little or no albumen. Acrid shrubs with very tough bark; leaves alternate.

95. Elaeagnaceae (p. 448). Flowers mostly dioecious. Calyx-tube becoming berry-like and enclosing the achene. Seed erect, albuminous. Leaves silvery-scurfy, opposite.

[*] 4. Ovary inferior, 1-celled, 1--3-ovuled (but 1-seeded); albumen without testa, bearing the embryo in a cavity at the apex; calyx-lobes valvate.

96. Loranthaceae (p. 449). Parasitic on trees, with jointed stems and opposite leaves. Flowers dioecious. Ovule solitary, erect. Fruit a berry.

97. Santalaceae (p. 450). Flowers perfect. Ovules 2--4, suspended from the apex of a central placenta. Fruit dry, indehiscent. Leaves alternate.

[*] 5. Flowers all unisexual (polygamous in some Urticaceae and Empetraceae, apparently perfect in Euphorbia); cells 1--2-ovuled; embryo nearly as long as the albumen or filling the seed; calyx often wanting, corolla-like only in some Euphorbiaceae and Empetraceae; stipules often present.

[+] 1. Ovary superior, 3-celled (1-celled in Crotonopsis) with 1 or 2 pendulous ovules in each cell; herbs.

98. Euphorbiaceae (p. 451). Flowers monoecious or dioecious (involucrate and apparently perfect in Euphorbia). Mostly with milky juice, and usually alternate often stipulate leaves.

[+] 2. Ovary 1-celled, 1-seeded; trees or shrubs (except some Urticaceae).

[++] Calyx regular, the stamens as many as the lobes and opposite them or fewer; ovary superior.

99. Urticaceae (p. 461). Flowers monoecious, dioecious, or (in Ulmeae) perfect. Seeds exalbuminous or nearly so. Inflorescence very various.

[++][++] Perianth mostly none; at least the staminate flowers in aments or spikes or dense heads; albumen none.

100. Platanaceae (p. 466). Trees, with alternate palmately lobed leaves, sheathing stipules, and monoecious flowers in separate globose heads. Ovary superior; fruit a club-shaped nutlet.

101. Juglandaceae (p. 467). Trees, with alternate pinnate leaves, no stipules, and monoecious flowers, the staminate in aments. Ovary inferior; fruit a nut.

102. Myricaceae (p. 469). Shrubs, with resinous-dotted leaves, with or without stipules, and monoecious or dioecious flowers, both kinds in short scaly aments. Ovary superior, becoming a small drupe-like nut.

[+] 3. Ovary 2--7-celled, with 1 or 2 suspended ovules in each cell, becoming 1-celled and 1-seeded; calyx mostly none or adherent to the ovary; trees or shrubs with simple leaves.

103. Cupuliferae (p. 470). Flowers monoecious. Fruit a nut surrounded by an involucre, or (in Betuleae) a small winged or angled naked nutlet in the axils of the scales of an ament.

[+] 4. Ovary 1-celled, becoming a 2-valved pod with two parietal or basal placentae bearing numerous small comose seeds; perianth none.

104. Salicaceae (p. 480). Dioecious trees or shrubs, with both kinds of flowers in aments, and simple alternate stipulate leaves.

[+] 5. Ovary several-celled, becoming a drupe containing 3--9 1-seeded nutlets; seed erect; low shrubby heath-like evergreens.

105. Empetraceae (p. 487). Flowers polygamous or dioecious, scaly-bracted. Sepals somewhat petaloid or none. Embryo axile in copious albumen.

[+] 6. Ovary 1-celled with a suspended ovule, becoming an achene; calyx none; aquatic herbs, with finely dissected whorled leaves.

106. Ceratophyllaceae (p. 488). Flowers monoecious, minute, axillary and sessile. Albumen none; the seed filled with a highly developed embryo.

SUBCLASS II. GYMNOSPERMOUS EXOGENS. Ovules naked upon a scale, bract, or disk. Cotyledons two or more.

107. Coniferae (p. 489). Resiniferous trees or shrubs, with mostly awl-shaped or needle-shaped and evergreen leaves, and monoecious or dioecious flowers.

CLASS II. MONOCOTYLEDONOUS PLANTS.

Stems without central pith or annular layers, but having the woody fibres distributed irregularly through them (a transverse slice showing the fibres as dots scattered through the cellular tissue). Embryo with a single cotyledon and the early leaves always alternate. Parts of the flower usually in threes (never in fives), and the leaves mostly parallel-veined. Our species herbaceous, excepting Smilax.

[*] Ovary inferior (superior in Bromeliaceae, nearly so in some Hemodoraceae); at least the inner lobes of the perianth petal-like.

[+] 1. Seeds without albumen, very numerous and minute.

108. Hydrocharidaceae (p. 495). Aquatics, with dioecious or polygamous flowers from a spathe; outer perianth calyx-like, the inner sometimes wanting. Stamens 3--12. Ovary 1-celled with 3 parietal placentae or 6--9-celled with axile placentae.

109. Burmanniaceae (p. 496). Terrestrial, with scale-like cauline leaves and regular perfect triandrous flowers. Perianth corolla-like.

110. Orchidaceae (p. 497). Terrestrial, with very irregular perfect flowers. Stamens and style connate; anthers 1 or 2. Capsule 1-celled; placentae 3, parietal. Perianth corolla-like.

[+] 2. Seeds albuminous. (Ovary 3-celled and flowers regular in our genera.)

111. Bromeliaceae (p. 511). Mostly epiphytes, with dry persistent scurfy leaves. Flowers 6-androus; outer perianth calyx-like.

112. Hemodoraceae (p. 512). Fibrous-rooted, with equitant leaves and perfect 3- or 6-androus flowers. Perianth persistent, woolly or scurfy outside. (Ovary sometimes nearly free; leaves flat in Aletris.)

113. Iridaceae (p. 513). Root not bulbous; leaves equitant in two ranks. Flowers from a spathe. Stamens 3, opposite the outer lobes of the corolla-like perianth; anthers extrorse.

114. Amaryllidaceae (p. 515). Often bulbous-rooted and scapose. Perianth corolla-like. Stamens 6; anthers introrse.

115. Dioscoreaceae (p. 517). Climbing, with net-veined leaves. Flowers dioecious, small, 6-androus; perianth calyx-like. Ovules 1 or 2 in each cell.

[*][*] Ovary superior (very rarely partially adnate to the calyx in Liliaceae).

[+] 1. At least the inner perianth corolla-like; ovary compound; seeds with copious albumen.

116. Liliaceae (p. 517). Flowers perfect, 6-androus, the regular perianth corolla-like (dioecious in Smilax, dimerous in Maianthemum, the outer divisions herbaceous in Trillium). Fruit a 3-celled capsule or berry.

117. Pontederiaceae (p. 535). Aquatic, with more or less irregular perfect flowers from a spathe; perianth corolla-like. Stamens 3 or 6, mostly unequal or dissimilar. Capsule 1-celled or imperfectly 3-celled.

118. Xyridaceae (p. 536). Rush-like, scapose. Flowers capitate, perfect, 3-androus, the calyx glumaceous. Capsule 1-celled.

119. Mayaceae (p. 537). Moss-like aquatic. Flowers perfect, axillary, solitary, 3-androus; calyx herbaceous. Capsule 1-celled.

120. Commelinaceae (p. 538). Flowers perfect, regular or somewhat irregular, with 3 more or less herbaceous persistent sepals and 3 fugacious petals. Stamens 6 or some sterile. Capsule 2--3-celled.

127. Eriocauleae (p. 566). Scapose aquatic or marsh plants, with linear leaves and dense heads of monoecious (rarely dioecious) minute flowers. Corolla tubular or none. Capsule 2--3-celled, 2--3-seeded.

[+] 2. Perianth small, of 6 equal persistent glumaceous segments; flowers perfect; ovary compound.

121. Juncaceae (p. 539). Rush-like. Stamens 3 or 6. Capsule 1- or 3-celled, 3-valved.

[+] 3. Flowers without chaffy glumes, the perianth none or reduced to bristles or sepal-like scales; flowers often monoecious or dioecious; carpels solitary or united.

[++] Flowers capitate or upon a spike or spadix, with or without a spathe.

122. Typhaceae (p. 547). Marsh or aquatic plants, with linear leaves, and monoecious flowers without proper perianth, in heads or a naked spike.

123. Araceae (p. 548). Flowers perfect or monoecious upon the same spadix, rarely dioecious, with 4 or 6 scale-like sepals or none.

[++][++] Flowers very minute, one or few from the margin of a floating disk-like frond.

124. Lemnaceae (p. 551). Plants very small, green, mostly lenticular or globose.

[+] 4. Perianth of 4 or 6 segments, the inner often petaloid, or none; carpels solitary or distinct (coherent in Triglochin); seeds without albumen; aquatic or marsh plants, often monoecious or dioecious.

125. Alismaceae (p. 553). Perianth of 6 segments, the inner petal-like.

126. Naiadaceae (p. 557). Perianth-segments herbaceous or none.

[+] 5. Flowers in the axils of chaffy scales or glumes arranged in spikes or spikelets, without evident perianth; stamens 1--3; ovary 1-celled, 1-seeded; seed albuminous.

128. Cyperaceae (p. 567). Scales single. Perianth none or replaced by bristles. Anthers basifixed. Fruit a triangular or lenticular achene. Stem solid, often triangular, with closed sheaths.

129. Gramineae (p. 623). Glumes in pairs. Perianth replaced by minute scales. Anthers versatile. Fruit a caryopsis. Culm usually hollow, terete; sheaths split to the base.

SERIES II. CRYPTOGAMOUS OR FLOWERLESS PLANTS; destitute of stamens and pistils, in fructification producing _spores_ instead of seeds.

CLASS III. ACROGENOUS PLANTS.

Cryptogamous plants with a distinct axis (stem and branches), growing from the apex only, and furnished for the most part with distinct leaves (sometimes taking the form of an expanded leaf-like usually prostrate _thallus_); reproduction by means of antheridia and archegonia, sometimes also by gemmation.

SUBCLASS I. VASCULAR ACROGENS, OR PTERIDOPHYTES. Stems (and foliage when present) containing both woody fibre and vessels; antheridia or archegonia, or both, borne on a minute prothallus, which is developed from the spore on germination.

[*] Spores of only one kind; prothallus bearing antheridia and archegonia.

130. Equisetaceae (p. 675). Cylindric jointed hollow-stemmed plants, with toothed sheaths. Fructification in a terminal spike.

131. Filices (p. 678). Ferns, with fronds circinate in vernation, bearing the fructification on the under surface or beneath the margin.

132. Ophioglossaceae (p. 693). Fronds often fern-like, erect in vernation. Sporangia globose, coriaceous, 2-valved, in special spikes or panicles.

133. Lycopodiaceae (p. 695). Low moss like plants with elongated stems and small persistent entire several-ranked leaves. Sporangia solitary, axillary, 1--3-celled, 2--3-valved.

[*][*] Spores of two kinds, the _macrospore_ producing a prothallus with archegonia, the _microspore_ smaller and developing antheridia.

134. Selaginellaceae (p. 697). Low leafy moss-like or marsh plants, with branching stems, and small 4--6-ranked leaves, or with a corm-like stem and basal linear-subulate leaves, the two kinds of spores in distinct solitary axillary 1-celled sporangia.

135. Marsiliaceae (p. 700). The two kinds of spores in the same or different sporangia which are borne in a coriaceous peduncled sporocarp arising from a slender creeping rhizome. Fronds digitately 4-foliolate or filiform.

136. Salviniaceae (p. 701). The two kinds of spores in separate thin-walled 1-celled sporocarps or conceptacles clustered beneath the small floating fronds; macrospores solitary.

SUBCLASS II. CELLULAR ACROGENS, OR BRYOPHYTES.

Plants with cellular tissue only; both antheridia and archegonia borne upon the plant itself.--Including the MUSCI, or Mosses (which are not treated of here), never thallose, and bearing capsules which usually dehisce by a lid and contain spores only, and the HEPATICAE, which bear capsules which dehisce by valves or irregularly and usually have elaters mingled with the spores. The latter division comprises the following Orders.

[*] Capsule 4-valved; plant a leafy axis or sometimes a branching thallus.

137. Jungermanniaceae (p. 702). Leaves, when present, without a midrib, 2-ranked, with often a third row beneath; pedicels slender.

[*][*] Capsule 2-valved, or dehiscing irregularly, or indehiscent; plant a thallus or thalloid stem.

138. Anthocerotaceae (p. 726). Thallus without epidermis, irregularly branching; pedicels stout or none. Capsule with a columella. Elaters mostly without fibres.

139. Marchantiaceae (p. 727). Thallus radiate or dichotomous, the epidermis usually porose. Capsules borne on the under side of a pedunculate receptacle, irregularly dehiscent. Elaters 2-spiral.

140. Ricciaceae (p. 730). Thallus radiate or dichotomous, the epidermis eporose. Capsules immersed in the thallus or sessile upon it, indehiscent. Elaters none.

ANALYTICAL KEY TO THE ORDERS.

CLASS I. DICOTYLEDONOUS PLANTS. (See p. 1.)

SUBCLASS I. ANGIOSPERMAE. Pistil consisting of a closed ovary. Cotyledons only two.

DIVISION I. POLYPETALOUS: the calyx and corolla both present; the latter of _separate_ petals.

[A.] _Stamens numerous, at least more than 10, and more than twice the sepals or lobes of the calyx._

[1.] _Calyx entirely free and separate from the pistil or pistils._

PAGE
Pistils numerous but cohering over each other in a solid mass on an
elongated receptacle. MAGNOLIACEAE, 49

Pistils numerous, separate, but concealed in a hollow receptacle.

Leaves opposite, entire; no stipules. CALYCANTHACEAE, 167

Leaves alternate, with stipules. Rosa, in ROSACEAE, 162

Pistils several, immersed in hollows of the upper surface of a large
top-shaped receptacle. Nelumbo, in NYMPHAEACEAE, 55

Pistils more than one, separate, not enclosed in the receptacle.

Stamens inserted on the calyx, distinct. ROSACEAE, 150

Stamens united with the base of the petals, monadelphous.
MALVACEAE, 96

Stamens inserted on the receptacle.

Filaments much shorter than the anther; trees. ANONACEAE, 50

Filaments longer than the anther.

Flowers dioecious; twiners with alternate leaves.
MENISPERMACEAE, 51

Flowers perfect; if climbers, the leaves opposite.

Leaves not peltate; petals deciduous. RANUNCULACEAE, 34

Leaves peltate; petals persistent.
Brasenia, in NYMPHAEACEAE, 55

Pistils several-lobed, the ovaries united below the middle.
RESEDACEAE, 75

Pistils several, their ovaries cohering in a ring around an axis.
MALVACEAE, 96

Pistils strictly one as to the ovary; the styles or stigmas may be
several.

Leaves punctate under a lens with transparent dots. HYPERICACEAE, 92

Leaves not punctate with transparent dots.

Ovary simple, 1-celled, 2-ovuled. ROSACEAE, 150

Ovary simple, 1-celled, with one parietal many-ovuled placenta.

Leaves 2--3-ternately compound or dissected. RANUNCULACEAE, 34

Leaves peltate, simply lobed. Podophyllum, in BERBERIDACEAE, 52

Ovary compound, 1-celled, with a central placenta.
PORTULACACEAE, 90

Ovary compound, 1-celled, with two or more parietal placentae.

Calyx caducous; juice milky or colored. PAPAVERACEAE, 57

Calyx deciduous, of 4 sepals. CAPPARIDACEAE, 74

Calyx persistent, of 3 or 5 sepals. CISTACEAE, 76

Ovary compound, several-celled.

Calyx valvate in the bud, and

Persistent; stamens monadelphous; anthers 1-celled.
MALVACEAE, 96

Deciduous; anthers 2-celled. TILIACEAE, 101

Calyx imbricated in the bud, persistent.

Shrubs; stamens on the base of the petals.
TERNSTROEMIACEAE, 95

Aquatic or marsh herbs; ovaries many,

On 5 placentae in the axis. SARRACENIACEAE, 57

On the 8--30 partitions. NYMPHAEACEAE, 54

[2.] _Calyx more or less coherent with the surface of the (compound) ovary._

Ovary 8--30-celled; ovules many, on the partitions; aquatic.
NYMPHAEACEAE, 54

Ovary 10-celled; cells 1-ovuled. Amelanchier, in ROSACEAE, 166

Ovary 2--5-celled.

Leaves alternate, with stipules. Pomeae, in ROSACEAE, 151

Leaves opposite, without stipules. Some SAXIFRAGACEAE, 168

Leaves alternate, without stipules. STYRACACEAE, 333

Ovary 1-celled, with the ovules parietal.

Fleshy plants with no true foliage; petals many. CACTACEAE, 186

Rough-leaved plants; petals 5 or 10. LOASACEAE, 193

Ovary one-celled, with the ovules rising from the base.
PORTULACACEAE, 90

[B.] _Stamens of the same number as the petals and opposite them._

Pistils 3--6, separate; flowers dioecious; woody vines.
MENISPERMACEAE, 51

Pistil only one.

Ovary one-celled; anthers opening by uplifted valves.
BERBERIDACEAE, 52

Ovary one-celled; anthers not opening by uplifted valves.

Style and stigma one; ovules more than one. PRIMULACEAE, 328

Style 1; stigmas 3; sepals 2; ovules several. PORTULACACEAE, 90

Style twice or thrice forked; flowers monoecious.
Crotonopsis, in EUPHORBIACEAE, 458

Styles 5; ovule and seed only one. PLUMBAGINACEAE, 327

Ovary 2--4-celled.

Calyx-lobes minute or obsolete; petals valvate. VITACEAE, 112

Calyx 4--5-cleft, valvate in the bud; petals involute.
RHAMNACEAE, 111

[C.] _Stamens not more than twice as many as the petals, when of just the number of the petals then alternate with them._

1. _Calyx free from the ovary, i.e. the ovary wholly superior._

[*] _Ovaries 2 or more, separate._

Stamens united with each other and with a large and thick stigma
common to the two ovaries. ASCLEPIADACEAE, 338

Stamens unconnected, on the receptacle, free from the calyx.

Leaves punctate with pellucid dots. RUTACEAE, 106

Leaves not pellucid-punctate.

Tree, with pinnate leaves. Ailanthus, in SIMARUBACEAE, 107

Low shrub, with pinnate leaves. Xanthorrhiza, in RANUNCULACEAE, 48

Herbs, not fleshy. RANUNCULACEAE, 34

Herbs, with thick fleshy leaves. CRASSULACEAE, 176

Stamens unconnected, inserted on the calyx.

Just twice as many as the pistils (flower symmetrical).
CRASSULACEAE, 176

Not just the number or twice the number of the pistils.

Leaves without stipules. SAXIFRAGACEAE, 168

Leaves with stipules. ROSACEAE, 150

[*][*] _Ovaries 2--5, somewhat united at the base, separate above._

Leaves punctate with pellucid dots. RUTACEAE, 106

Leaves not pellucid-punctate.

Shrubs or trees with opposite leaves. SAPINDACEAE, 115

Terrestrial herbs; the carpels fewer than the petals.
SAXIFRAGACEAE, 168

[*][*][*] _Ovaries or lobes of ovary 3 to 5, with a common style._
GERANIACEAE, 102

[*][*][*][*] _Ovary only one, and_

[+] _Simple, with one parietal placenta._ LEGUMINOSAE, 122

[+][+] _Compound, as shown by the number of cells, placentae, styles, or stigmas._

Ovary one-celled.

Corolla irregular; petals 4; stamens 6. FUMARIACEAE, 59

Corolla irregular; petals and stamens 5. VIOLACEAE, 78

Corolla regular or nearly so.

Ovule solitary; shrubs or trees; stigmas 3. ANACARDIACEAE, 118

Ovules solitary or few; herbs. Some anomalous CRUCIFERAE, 61

Ovules more than one, in the centre or bottom of the cell.

Petals not inserted on the calyx. CARYOPHYLLACEAE, 82

Petals on the throat of a bell-shaped or tubular calyx.
LYTHRACEAE, 184

Ovules several or many, on two or more parietal placentae.

Leaves punctate with pellucid and dark dots. HYPERICACEAE, 92

Leaves beset with reddish gland-tipped bristles.
DROSERACEAE, 178

Leaves neither punctate nor bristly-glandular.

Sepals 5, very unequal or only 3. CISTACEAE, 76

Sepals and petals 4; stamens 6. Anomalous CRUCIFERAE, 61

Sepals and petals 5; stamens 5 or 10.

Ovary and stamens raised on a stalk. PASSIFLORACEAE, 194

Ovary sessile. SAXIFRAGACEAE, 168

Ovary 2--several-celled.

Flowers irregular.

Anthers opening at the top,

Six or eight and 1-celled; ovary 2-celled, 2-ovuled.
POLYGALACEAE, 120

Ten and 2-celled; ovary 5-celled.
Rhododendron, in ERICACEAE, 286

Anthers opening lengthwise.

Stamens 12 and petals 6 on the throat of a tubular inflated or
gibbous calyx. Cuphea, in LYTHRACEAE, 186

Stamens 5--8 or 10, and petals hypogynous, or nearly so.

Ovary 3-celled. SAPINDACEAE, 115

Ovary 5-celled. Impatiens, &c., in GERANIACEAE, 105

Flowers regular or nearly so.

Stamens neither just as many nor twice as many as the petals,

Triadelphous; petals 5. HYPERICACEAE, 92

Tetradynamous (or rarely only 2 or 4); petals 4; pungent
herbs. CRUCIFERAE, 61

Distinct and fewer than the 4 petals. OLEACEAE, 335

Distinct and more numerous than the petals. SAPINDACEAE, 115

Stamens just as many or twice as many as the petals.

Ovules and seeds only 1 or 2 in each cell.

Herbs; flowers monoecious or dioecious. EUPHORBIACEAE, 451

Herbs; flowers perfect and symmetrical.

Cells of the ovary as many as the sepals, &c.
GERANIACEAE, 102

Cells of the (divided) ovary twice as many as the styles,
sepals, &c. LINACEAE, 101

Shrubs or trees.

Leaves 3-foliolate, pellucid-punctate.
Ptelea, in RUTACEAE, 107

Leaves palmately veined and fruit 2-winged, or pinnate and
fruit a berry. SAPINDACEAE, 115

Leaves pinnately veined, simple, not punctate.

Calyx not minute; pod colored, dehiscent; seeds enclosed
in a pulpy aril. CELASTRACEAE, 109

Calyx minute; fruit a berry-like drupe. ILICINEAE, 107

Ovules (and usually seeds) several or many in each cell.

Stipules between the opposite and simple leaves.
ELATINACEAE, 91

Stipules between the opposite and compound leaves (but they
are caducous). Staphylea, in SAPINDACEAE, 118

Stipules none when the leaves are opposite.

Stamens 5, monadelphous in a 10-toothed tube or cup;
leaves simple, all radical. Galax, in DIAPENSIACEAE, 326

Stamens 10, monadelphous at the base. Leaflets 3,
inversely heart-shaped. Oxalis, in GERANIACEAE, 105

Stamens distinct, free from the calyx.

Style 1, undivided. ERICACEAE, 303

Styles 2--5, separate. CARYOPHYLLACEAE, 82

Stamens distinct, inserted on the calyx.

Styles 2 (or 3), or splitting into 2 in fruit.
SAXIFRAGACEAE, 168

Style 1; pod in the calyx, 1-celled. LYTHRACEAE, 184

[2.] _Calyx-tube adherent to the ovary, at least to its lower half._

Tendril-bearing and often succulent herbs. CUCURBITACEAE, 194

Not tendril-bearing.

Ovules and seeds more than one in each cell.

Ovary 1-celled, many-ovuled from the base. PORTULACACEAE, 90

Ovary 1-celled, with 2 or 3 parietal placentae. SAXIFRAGACEAE, 168

Ovary 2--several-celled.

Anthers opening by pores at the apex; style 1.
MELASTOMACEAE, 183

Anthers not opening by pores.

Stamens on a flat disk which covers the ovary.
CELASTRACEAE, 109

Stamens inserted on the calyx.

Eight or four (rarely five); style 1. ONAGRACEAE, 186

Five or ten; styles 2--3, distinct. SAXIFRAGACEAE, 168

Ovules and seeds only one in each cell.

Stamens 10 or 5 (instead of many),--
rarely in Crataegus, in ROSACEAE, 165

Stamens 2 or 8; style 1; stigma 2--4-lobed; herbs.
ONAGRACEAE, 186

Stamens 4 or 8; aquatics; styles or sessile stigmas 4.
HALORAGEAE, 180

Perfect stamens 4; styles 2; shrub. HAMAMELIDEAE, 179

Stamens 4; style and stigma 1; chiefly shrubs. CORNACEAE, 213

Stamens 5; flowers in umbels, or rarely in heads.

Fruit dry, splitting in two at maturity; styles 2.
UMBELLIFERAE, 193

Fruit berry-like; styles 2--5, separate or united.
ARALIACEAE, 212

Division II. GAMOPETALOUS calyx and corolla both present; the latter with its petals united more or less into one piece.

[A.] _Stamens more numerous than the lobes of the corolla._

Ovary 1-celled with one parietal placenta. LEGUMINOSAE, 122

Ovary 1-celled with two parietal placentae.
Adlumia, &c., in Fumariaceae, 60

Ovary 1-celled with the ovules at the centre or base. STYRACACEAE, 333

Ovary 2-celled with a single ovule in each cell. POLYGALACEAE, 120

Ovary 3--many-celled.

Stamens free or nearly free from the corolla; style single.
ERICACEAE, 309

Stamens free from the corolla; styles 5. Oxalis, in GERANIACEAE, 105

Stamens inserted on the base or tube of the corolla.

Filaments monadelphous; anthers 1-celled, kidney-shaped.
MALVACEAE, 96

Filaments 1--5-adelphous at base; anthers 2-celled.

Calyx free from the ovary. TERNSTROEMIACEAE, 96

Calyx coherent with the ovary or with its base. STYRACACEAE, 333

Filaments wholly distinct; calyx free, persistent. EBENACEAE, 333

Filaments in pairs at each sinus; anthers 1-celled.
CAPRIFOLIACEAE, 216

[B.] _Stamens (fertile ones) as many as the lobes of the corolla and opposite them._

Ovary 5-celled; corolla appendaged with scales inside. SAPOTACEAE, 332

Ovary 1-celled; pod several--many-seeded; style 1. PRIMULACEAE, 328

Ovary 1-celled; utricle 1-seeded; styles 5. PLUMBAGINACEAE, 327

[C.] _Stamens as many as the lobes of the corolla and alternate with them, or fewer._

[1.] _Ovary adherent to the calyx-tube (inferior)._

Tendril-bearing herbs; anthers often united. CUCURBITACEAE, 194

Tendrils none.

Stamens united by their anthers into a ring or tube.

Flowers in an involucrate head. COMPOSITAE, 230