Chapter L: VULGARE, L. (PRIVET, or PRIM.) Leaves very smooth; berries

black.--Used for low hedges, and naturalized eastward; from Europe.

ORDER 66. APOCYNACEAE. (DOGBANE FAMILY.)

_Plants almost all with milky acrid juice, entire (chiefly opposite) leaves without stipules, regular 5-merous and 5-androus flowers; the 5 lobes of the corolla convolute and twisted in the bud; the filaments distinct, inserted on the corolla, and the pollen granular_; calyx free from the two ovaries, which (in our genera) are distinct (forming follicles), though their styles or stigmas are united into one.--Seeds amphitropous or anatropous, with a large straight embryo in sparing albumen, often bearing a tuft of down (comose).--Chiefly a tropical family (of acrid-poisonous plants), represented in gardens by the Oleander and Periwinkle.

1. Amsonia. Seeds naked. Corolla-tube bearded inside. Anthers longer than the filaments. Leaves alternate.

2. Trachelospermum. Seeds comose. Corolla funnel-form, not appendaged. Filaments slender. Calyx glandular inside. Leaves opposite.

3. Apocynum. Seeds comose. Corolla bell-shaped, appendaged within. Filaments short, broad and flat. Calyx not glandular. Leaves opposite.

1. AMSONIA, Walt.

Calyx 5-parted, small. Corolla with a narrow funnel-form tube bearded inside, especially at the throat; the limb divided into 5 long linear lobes. Stamens 5, inserted on the tube, included; anthers obtuse at both ends, longer than the filaments. Ovaries 2; style 1; stigma rounded, surrounded with a cup-like membrane. Pod (follicles) 2, long and slender, many-seeded. Seeds cylindrical, abrupt at both ends, packed in one row, naked.--Perennial herbs, with _alternate leaves_, and pale blue flowers in terminal panicled cymes. (Said to be named for a _Mr. Charles Amson_.)

1. A. Tabernaemontana, Walt. Loosely pubescent or hairy when young, soon glabrous; leaves from ovate-lanceolate to linear-lanceolate, taper-pointed; calyx-lobes short, awl-shaped; tube of the bluish corolla little longer than the lobes, the upper part either hairy when young or glabrous.--Low grounds, N. C. to S. Ind. and Mo., south to Fla. and Tex. May, June.

2. TRACHELOSPERMUM, Lemaire.

Calyx 5-parted, with 3--5 glands at its base inside. Corolla funnel-form, not appendaged; limb 5-lobed. Stamens 5, included; filaments slender; anthers arrow-shaped, with an inflexed tip. Pods (follicles) 2, slender, many-seeded. Seeds oblong, with a tuft of down.--Twining plants, more or less woody, with opposite leaves and small flowers in cymes. (Name from [Greek: tra/xelos], _a neck_, and [Greek: spe/rma], _seed_, upon the supposition that the seed was beaked.)

1. T. difforme, Gray. Nearly herbaceous and glabrous; leaves oval-lanceolate, pointed, thin; calyx-lobes taper-pointed; corolla pale yellow. (Forsteronia difformis, _A. DC._)--Damp grounds, Va. to Fla. and Tex. April.

3. APOCYNUM, Tourn. DOGBANE. INDIAN HEMP.

Calyx 5-parted, the lobes acute. Corolla bell-shaped, 5-cleft, bearing 5 triangular appendages below the throat opposite the lobes. Stamens 5, on the very base of the corolla; filaments flat, shorter than the arrow shaped anthers, which converge around the stigma, and are slightly adherent to it. Style none; stigma large, ovoid, slightly 2-lobed. Fruit of 2 long (2--7') and slender follicles. Seeds comose, with a tuft of long silky down at the apex.--Perennial herbs, with upright branching stems, opposite mucronate-pointed leaves, a tough fibrous bark, and small and pale cymose flowers on short pedicels. (Ancient name of the Dogbane, composed of [Greek: a)po/], _from_, and [Greek: ky/on], _a dog_.)

1. A. androsaemifolium, L. (SPREADING DOGBANE.) Smooth, or rarely soft-tomentose, branched above; _branches divergently forking; leaves ovate, distinctly petioled; cymes loose, spreading_, mostly longer than the leaves; _corolla_ (pale rose-color, 4'' broad) _open-bell-shaped, with revolute lobes, the tube much longer than the ovate pointed divisions of the calyx_.--Borders of thickets; common. June, July.

2. A. cannabinum, L. (INDIAN HEMP.) Glabrous or more or less soft-pubescent; stem and branches _upright or ascending_ (2--3 deg. high), terminated by _erect and close many-flowered cymes_, which are usually shorter than the leaves; leaves from oval to oblong and even lanceolate, short-petioled or sessile, with rounded or obscurely cordate base; _corolla_ (greenish-white) _with nearly erect lobes, the tube not longer than the lanceolate divisions of the calyx_.--Moist grounds and banks of streams; common. Very variable. July, Aug.

ORDER 67. ASCLEPIADACEAE. (MILKWEED FAMILY.)

_Plants with milky juice, and opposite or whorled (rarely scattered) entire leaves; the follicular pods, seeds, anthers (connected with the stigma), sensible properties, etc., just as in the last family, from which they differ in the commonly valvate corolla, and in the singular connection of the anthers with the stigma, the cohesion of the pollen into wax-like or granular masses_ (pollinia), etc., as explained under the typical genus Asclepias.

PERIPLOCA GRAECA, L., a woody climbing plant of the Old World, in ornamental cultivation, and in one or two places inclined to be spontaneous, represents a tribe with granulose pollen loosely aggregated in two masses in each anther-cell. It has a brownish rotate corolla, very hairy within, and with 5 awned scales in the throat.

Tribe I. CYNANCHEAE. Anthers tipped with an inflexed or sometimes erect scarious membrane, the cells lower than the top of the stigma; pollinia suspended.

[*] Stems erect or merely decumbent.

1. Asclepiodora. Corolla rotate, merely spreading. Crown of 5 hooded fleshy bodies, with a salient crest in each. Leaves alternate.

2. Asclepias. Corolla reflexed, deeply 5-parted. Crown as in n. 1, but with an incurved horn rising from the cavity of each hood. Leaves usually opposite.

3. Acerates. Corolla reflexed or merely spreading. Crown as in n. 1, but with neither crest nor horn inside. Leaves mainly alternate.

[*][*] Stems twining. Leaves mostly opposite.

4. Enslenia. Corolla erect. Crown of 5 membranaceous flat bodies, terminated by a 2-cleft tail or awn.

5. Vincetoxicum. Corolla rotate, spreading. Crown a fleshy 5--10-lobed ring or disk.

Tribe II. GONOLOBEAE. Anthers with short if any scarious tip, borne on the margin of or close under the disk of the stigma; pollinia horizontal.

6. Gonolobus. Corolla rotate. Crown a wavy-lobed fleshy ring. Stems twining.

1. ASCLEPIODORA, Gray.

Nearly as in Asclepias, but the corolla-lobes ascending or spreading, and the hoods destitute of a horn, widely spreading and somewhat incurved, slipper-shaped and laterally compressed, the cavity divided at the apex by a crest-like partition.--Umbels solitary and terminal or corymbed, loosely-flowered. Follicles oblong or ovate, often somewhat muricate with soft spinous projections. ([Greek: A)sklepio/s] and [Greek: do~ron] or [Greek: dorea/], _the gift of AEsculapius_.)

1. A. viridis, Gray. Almost glabrous; stems short (1 deg. high); leaves alternate, short-petioled, ovate-oblong to lanceolate, 1--2' wide; umbels several in a cluster, short-peduncled; flowers large (1' in diameter), green, with a purplish crown. (Acerates paniculata, _Decaisne_.)--Prairies, Ill. to Tex. and S. Car. June.

2. ASCLEPIAS, L. MILKWEED. SILKWEED.

Calyx 5-parted, persistent; the divisions small, reflexed. Corolla deeply 5-parted, the divisions valvate in the bud, reflexed, deciduous. _Crown_ of 5 hooded bodies seated on the tube of stamens, each containing an incurved horn. Stamens 5, inserted on the base of the corolla; filaments united in a tube which encloses the pistil, anthers adherent to the stigma, each with 2 vertical cells, tipped with a membranaceous appendage, each cell containing a flattened pear-shaped and waxy pollen-mass; the two contiguous pollen-masses of adjacent anthers, forming pairs which hang by a slender prolongation of their summits from 5 cloven glands that grow on the angles of the stigma (extricated from the cells by insects, and directing copious pollen-tubes into the point where the stigma joins the apex of the style). Ovaries 2, tapering into very short styles; the large depressed 5-angled fleshy stigmatic disk common to the two. Follicles 2, one of them often abortive, soft, ovate or lanceolate. Seeds anatropous, flat, margined, bearing a tuft of long silky hairs (_coma_) at the hilum, downwardly imbricated all over the large placenta, which separates from the suture at maturity. Embryo large, with broad foliaceous cotyledons in thin albumen.--Perennial upright herbs, with thick and deep roots; peduncles terminal or lateral and between the usually opposite petioles, bearing simple many-flowered umbels, in summer. (The Greek name of _AEsculapius_, to whom the genus is dedicated.)

Sec. 1. _Corneous anther-wings broadest and usually angulate-truncate and salient at base; horn conspicuous._

[*] _Flowers orange-color; leaves mostly scattered; juice not milky._

1. A. tuberosa, L. (BUTTERFLY-WEED. PLEURISY-ROOT.) Roughish-hairy (1--2 deg. high); stems erect or ascending, very leafy, branching at the summit, and bearing usually numerous umbels in a terminal corymb; leaves from linear to oblong-lanceolate, sessile or slightly petioled; divisions of the corolla oblong (greenish-orange); hoods narrowly oblong, bright orange, scarcely longer than the nearly erect and slender awl-shaped horns; pods hoary, erect on deflexed pedicels.--Dry fields, common, especially southward.--Var. DECUMBENS, Pursh. Stems reclining; leaves broader and more commonly opposite, and umbels from most of the upper axils.--Ohio to Ga., etc.

[*][*] _Corolla bright red or purple; follicles naked, fusiform, erect on the deflexed pedicels_ (except in n. 5); _leaves opposite, mostly broad_.

[+] _Flowers rather large; hoods about 3'' long and exceeding the anthers; leaves transversely veined._

2. A. paupercula, Michx. Glabrous; stem slender (2--4 deg. high); leaves elongated-lanceolate or linear (5--10' long), tapering to both ends, slightly petioled, _umbels 5--12-flowered_; divisions of the red corolla narrowly oblong; the _bright orange hoods_ broadly oblong, obtuse, much exceeding the incurved horn.--Wet pine-barrens on the coast, N. J. to Fla. and Tex.

3. A. rubra, L. _Glabrous; leaves ovate or lanceolate and tapering from a rounded or heart-shaped base_ to a very acute point, sessile or nearly so (2--6' long, 1/2--21/2' wide), bright green; umbels many-flowered; divisions of the corolla and hoods _oblong-lanceolate, purple-red; the horn long and slender, straightish_.--Wet pine-barrens, etc., N. J. and Penn. to Fla., La., and Mo.

4. A. purpurascens, L. (PURPLE M.) Stem rather slender (1--3 deg. high); _leaves elliptical or ovate-oblong_, the upper taper-pointed, _minutely velvety-downy underneath_, smooth above, _contracted at base into a short petiole; pedicels_ shorter than the peduncle, _3--4 times the length of the dark purple lanceolate-ovate divisions of the corolla_; hoods oblong, abruptly narrowed above; _the horn broadly scythe-shaped, with a narrow and abruptly inflexed horizontal point_.--Dry ground, N. Eng. to Minn., Tenn., and southward.--Flowers 6'' long.

[+][+] _Flowers small; hoods 1'' long, equalling the anthers; veins ascending._

5. A. incarnata, L. (SWAMP MILKWEED.) Smooth, or nearly so, in the typical form, the stem with two downy lines above and on the branches of the peduncles (2--3 deg. high), very leafy; leaves oblong-lanceolate, acute or pointed, obtuse or obscurely heart-shaped at base; flowers rose-purple; hoods scarcely equalling the slender needle-pointed horn.--Swamps, common.--Var. PULCHRA, Pers.; leaves broader and shorter-petioled, more or less hairy-pubescent, as well as the stem. Milky juice scanty.--With the smooth form.

[*][*][*] _Flowers greenish, yellowish, white, or merely purplish-tinged; leaves opposite or whorled, or the upper rarely scattered._

[+] _Follicles echinate with soft spinous processes, densely tomentose (smooth, and only minutely echinate at the apex in n. 8), large (3--5' long), ovate and acuminate, erect on deflexed pedicels; leaves large and broad, short-petioled; umbels terminal and lateral._

6. A. speciosa, Torr. Finely canescent-tomentose or glabrate, _the many-flowered umbel and calyx densely tomentose_; leaves _subcordate-oval_ to oblong; corolla-lobes purplish, ovate-oblong, 4--5'' long; hoods 5--6'' long, with a short inflexed horn, _the truncate summit abruptly produced into a very long lanceolate-ligulate appendage_.--Along streams, Minn. to Ark., and westward.

7. A. Cornuti, Decaisne. (COMMON MILKWEED or SILKWEED.) Stem tall and stout, finely soft-pubescent; _leaves_ oval-oblong (4--8' long), pale, _minutely downy beneath, as well as the peduncles_, etc.; corolla-lobes dull purple to white, 3--4'' long; _hoods_ rather longer than the anthers, _ovate, obtuse, with a tooth each side of the short stout claw-like horn_.--Rich ground, everywhere.

8. A. Sullivantii, Engelm. _Very smooth_ throughout, tall; leaves ovate-oblong with a somewhat heart-shaped base, nearly sessile; _hoods obovate_, entire, _obtusely 2-eared at the base_ outside; flowers larger (9'' long) and more purple than in the last; anther-wings 2-toothed at base; _pod_ nearly glabrous, obscurely _spiny chiefly on the beak_.--Low grounds, Ohio to Kan. and Minn.

[+][+] _Follicles wholly unarmed, either glabrous or tomentulose-pubescent_.

[++] _Erect or ascending on the deflexed or decurved fruiting pedicels._

[=] _Umbel solitary, on a naked terminal peduncle; leaves sessile, broad, transversely veined, wavy; glabrous and pale or glaucous._

9. A. Obtusifolia, Michx. Stem 2--3 deg. high; _leaves oblong with a heart-shaped clasping base_, very obtuse or retuse (21/2--5' long); peduncle 3--12' long; corolla pale greenish purple; hoods truncate, somewhat toothed at the summit, shorter than the slender awl-pointed horn.--Sandy woods and fields, not rare, especially southward. A second umbel at the base of the peduncle occasionally occurs.

10. A. Meadii, Torr. Stem slender (1--2 deg. high); leaves _ovate or oblong-ovate_, obtuse or acutish (11/2--21/2' long), peduncle only twice the length of the upper leaves, pedicels rather short, corolla greenish-white; hoods rounded-truncate at summit, and with a sharp tooth at each margin, somewhat exceeding the stouter horn.--Dry ground, Ill. and Iowa. June.

[=][=] _Umbels mostly more than one; peduncle not overtopping the leaves._

[a.] _Leaves large, orbicular to oblong-lanceolate; hoods broad, little if at all exceeding the anthers; glabrous or some minute pubescence on young parts._

11. A. Jamesii, Torr. Stem stout (1 deg. high or more); leaves about 5 pairs, approximate, _remarkably thick, rounded or broadly oval, often emarginate, subcordate at base, nearly sessile_; umbels 2--3, densely many-flowered, on short peduncles, corolla-lobes ovate, _greenish_; hoods truncate, entire.--Plains of central Kansas and southwestward.

12. A. phytolaccoides, Pursh. (POKE-MILKWEED.) Stem 3--5 deg. high; _leaves broadly ovate, or the upper oval-lanceolate and pointed at both ends, short-petioled_, smooth or slightly downy underneath (5--8' long); lateral umbels several, _pedicels loose and nodding, numerous, long_ and slender (1--3' long), equalling the peduncle; _corolla-lobes_ ovate-oblong, greenish; hoods (white) truncate, the margins 2-toothed at the summit, _the horn with a long projecting awl-shaped point_.--Moist copses, N. Eng. to Minn., south to Ga. and Ark.

13. A. variegata, L. Stem 1--2 deg. high; _leaves_ (4--5 pairs) _ovate, oval, or obovate_, somewhat wavy, _contracted into short petioles_, middle ones sometimes whorled; _pedicels (numerous and crowded) and peduncle short, downy_; divisions of the _corolla ovate (white)_; hoods orbicular, entire, purplish or reddish, the horn semilunar with a horizontal point.--Dry woods, southern N. Y. to Ind., south to Fla., Ark., and W. La. July.--Remarkable for its compact umbels of nearly white flowers.

[b.] _Leaves mostly pubescent or puberulent; hoods obtuse, entire, twice or thrice the length of the anthers._

14. A. ovalifolia, Decaisne. Low (6--18' high), soft-downy, especially the lower surface of the ovate or lanceolate-oblong acute short-petioled leaves (11/2--3' long); umbels loosely 10--18-flowered, sessile or peduncled; pedicels slender, hoods oblong, yellowish, with a small horn, about the length of the oval greenish-white corolla-lobes (tinged with purple outside).--Prairies and oak-openings, N. Ill. and Iowa, to Wisc. and Dak.

[++][++] _Follicles and pedicels erect; leaves often whorled; glabrous or nearly so._

[=] _Leaves ovate to broadly lanceolate, thin, rather slender-petioled._

15. A. quadrifolia, L. Stem slender (1--2 deg. high), mostly leafless below, bearing usually _one or two whorls_ of four in the middle and one or two pairs _of ovate or ovate-lanceolate_ taper-pointed petioled leaves (2--4' long); pedicels slender; corolla-lobes (_pale pink_) oblong; hoods white, elliptical-ovate, the incurved horn short and thick.--Dry woods and hills, N. Eng. to Minn., south to N. C. and Ark.

16. A. perennis, Walt. Stems (1--2 deg. high) _persistent or somewhat woody at the base; leaves lanceolate or lanceolate-ovate, tapering to both ends_, thin, rather slender-petioled; _flowers white_, small; the small hoods of the crown shorter than the needle-shaped horn; seeds sometimes destitute of a coma!--Low grounds, S. Ind. and Ill. to Tex., and eastward.

[=][=] _Leaves narrowly linear to filiform; horn subulate, exserted; column conspicuous._

17. A. verticillata, L. Stems slender, simple or sparingly branched, very leafy to the summit, leaves filiform-linear, with revolute margins (2--3' long, 1'' wide), 3--6 in a whorl; umbels small, lateral and terminal; divisions of the corolla ovate (greenish-white); hoods roundish-oval, about half the length of the incurved claw-shaped horns.--Dry hills, common, especially southward.--Var. PUMILA, Gray, is low and many-stemmed from a fascicled root; leaves much crowded, filiform.--Dry plains, Neb. to Kan. and N. Mex.

Sec. 2. _Anther-wings broadly rounded at base and conspicuously auriculate-notched just above it; hoods with a minute horn exserted from the 2-lobed apex._

18. A. stenophylla, Gray. Puberulent, but foliage glabrous; stems slender (1--2 deg. high), leaves narrowly linear (3--7' long, 1--21/2'' wide), the upper alternate, lower opposite; umbels several, short-peduncled, 10--15-flowered; corolla-lobes oblong, greenish; hoods whitish, equalling the anthers, conduplicate-concave; follicles erect on ascending pedicels.--Dry prairies, Neb. to E. Kan., south and westward.

3. ACERATES, Ell. GREEN MILKWEED.

Nearly as in Asclepias; but the hoods destitute of crest or horn (whence the name, from [Greek: a] privative, and [Greek: ke/ras], _a horn_).--Flowers greenish, in compact many-flowered umbels. Leaves opposite or irregularly alternate, short-petioled or sessile. Pollen-masses slender-stalked. Follicles smooth, slender.

[*] _Crown upon a short column and shorter than the globular mass of anthers and stigma, leaves mainly alternate-scattered._

1. A. longifolia, Ell. Minutely roughish-hairy or smoothish; stem erect (1--3 deg. high), very leafy; leaves linear (3--7' long); umbels lateral, on peduncles of about the length of the slender pedicels; flowers 3'' long when expanded.--Moist prairies and pine-barrens, Ohio to Minn., south to Fla. and Tex. July--Oct.

[*][*] _Crown sessile, the oblong hoods nearly equalling the anthers; leaves often opposite and broader._

2. A. viridiflora, Ell. Minutely _soft-downy, becoming smoothish_; stems ascending (1--2 deg. high); leaves oval to linear, thick (11/2--4' long); _umbels nearly sessile, lateral_, dense and globose; flower (when the corolla is reflexed) nearly 1/2' long, short-pedicelled.--Dry soil, common, especially southward. July--Sept.--Runs into var. LANCEOLATA, Gray, with lanceolate leaves 21/2--4' long;--and var. LINEARIS, Gray, with elongated linear leaves and low stems; umbels often solitary. The latter form from Minn., Dak., and southward.

3. A. lanuginosa, Decaisne. _Hairy_, low (5--12' high); leaves lanceolate or ovate-lanceolate; _umbel solitary and terminal, peduncled_; flowers smaller; _pedicels slender_.--Prairies, N. Ill. to Minn., and westward. July.

4. ENSLENIA, Nutt.

Calyx 5-parted. Corolla 5-parted; the divisions erect, ovate-lanceolate. Crown of 5 free membranaceous leaflets, which are truncate or obscurely lobed at the apex, where they bear a pair of flexuous awns united at base. Anthers nearly as in Asclepias; pollen-masses oblong, obtuse at both ends, fixed below the summit of the stigma to the descending glands. Follicles oblong-lanceolate, smooth. Seeds with a tuft, as in Asclepias.--A perennial twining herb, smooth, with opposite heart-ovate and pointed long-petioled leaves, and small whitish flowers in raceme-like clusters, on slender axillary peduncles. (Dedicated to _A. Enslen_, an Austrian botanist who collected in the Southern United States early in the present century.)

1. E. albida, Nutt. Climbing 8--12 deg. high; leaves 3--5' wide.--River-banks, S. Penn. and Va. to Ill., Mo., and Tex. July--Sept.

5. VINCETOXICUM, Moench.

Calyx 5-parted. Corolla 5-parted, wheel-shaped. Crown flat and fleshy, disk-like, 5--10-lobed, simple. Anthers, smooth follicles and seeds much as in Asclepias.--Herbs, often twining. (Name from _vincens_, binding, and _toxicum_, poison.)