Chapter I: Edible Plums (5)

Plant a small tree, attaining a height of twenty-five feet;
trunk small but well-defined; branches spreading, bushy,
sometimes armed with spinescent branchlets; young wood slender,
more or less zigzag, usually glabrous, glossy, reddish but
approaching a chestnut-brown; lenticels few, scattered,
yellowish, raised.

Leaves oblong, oval-lanceolate or rarely slightly
obovate-lanceolate, one and one-fifth to two and one-fifth
inches long, three-quarters to one inch broad, gradually
narrowed at the base, acute at the apex; margins very minutely
glandular-serrate; upper surface glabrous and somewhat
lustrous; lower surface paler, glabrous or sparingly hairy
along the midrib and in the axils of the lateral veins;
petioles slender, usually reddish, about one-half inch long,
pubescent along the upper side, eglandular or sometimes with
one or two glands at the apex; stipules small, linear and
glandular-dentate.

Flowers appearing from early in March and before the leaves
in the South, to the middle of April and with the leaves in
the North, in dried specimens about one-half inch broad;
pedicels three-eighths to one-half inch long, glabrous;
calyx campanulate, the tube glabrous; calyx-lobes usually
shorter than the tube, oblong and obtuse, glabrous on the
outer surface, glabrous or sometimes sparingly pubescent on
the inner, the margin ciliate, eglandular; petals obovate,
gradually narrowed toward the base, erose or entire toward the
apex.

Fruit globose or sub-globose, varying from red to yellow,
usually with a light bloom; stone about one-half inch long,
two-fifths inch broad, turgid, ovoid to elliptic-oblong,
obscurely pointed at the apex or sometimes slightly obtuse,
truncate or obliquely truncate at the base, grooved on the
dorsal edge, ventral edge with a narrow, thickened and slightly
grooved wing, the surfaces irregularly roughened.

Yellow Transparent may be considered a typical variety. Type specimens in the Economic Collection of the Department of Agriculture were collected at the Eastern Shore Nurseries of J. W. Kerr, Denton, Maryland, (flowers) I. Tidestrom, April, 1910; (foliage and fruit) P. L. Ricker No. 2933, June 29, 1909.

In the wild, _Prunus angustifolia varians_ forms dense thickets, the larger specimens attaining a height of ten or twelve feet. When budded and grown in the orchard it assumes the form of a small tree with well defined trunk and spreading branches, sometimes armed with rather slender spinescent branchlets. It is distinguished from the species by its usually more robust habit, by its having the young twigs less reddish and approaching a chestnut-brown in color, rather longer leaves, longer pediceled flowers, and by the stone in most cases being more pointed at the apex. Usually in more fertile soil than the species, it occurs locally from southern Oklahoma through eastern Texas southward possibly to the Colorado River, and probably westward to the Panhandle region. As yet, however, its distribution is not well defined.

Nearly all of the early ripening horticultural varieties previously referred to _Prunus angustifolia_ belong to _Prunus angustifolia varians_. The fruit of the sub-species appears to be superior to that of the species though scarcely equal to that of the other southern plums now cultivated. Hybrids between this form and _Prunus munsoniana_ undoubtedly occur freely both in the wild state and under cultivation. The varieties Eagle and El Paso have probably originated in this way. Nearly all of the plums belonging to this species, some twenty in all, are tender to cold, none, so far as is known, succeeding in the North. African, Cluck, Jennie Lucas and Yellow Transparent may be named as representative varieties.

=19.= =PRUNUS MUNSONIANA=[139] Wight and Hedrick

_Prunus angustifolia._ =1.= Bailey _Cornell Sta. Bul._ =38=:58.
1892 (in part). =2.= Ibid. _Ev. Nat. Fr._ 191-194. 1898 (in
part). =3.= Waugh _Vt. Sta. An. Rpt._ =10=:99, 105. 1897 (in
part).

_Prunus hortulana._ =4.= Bailey _Cornell Sta. Bul._ =38=:48.
1892 (in part). =5.= Waugh _Vt. Sta. An. Rpt._ =10=:99,
103-105. 1896-97 (in part).

Tree medium to large, from twenty to thirty feet in height;
trunk six to ten inches in diameter; bark grayish-brown,
shaggy, furrowed; branches spreading, rather slender, zigzag,
little or not at all thorny; branchlets slender, zigzag,
reddish, lustrous, glabrous; lenticels numerous, large, raised.

Winter-buds small, short, obtuse, usually free; leaves one and
one-quarter inches wide by four inches long, lanceolate to
oblong-lanceolate, sometimes broadly so, somewhat folded, apex
acute or tapering, usually rounded at the base, texture thin,
margins closely and finely serrate, teeth with small, dark red
glands; upper surface bright green, glabrous, lustrous; lower
surface dull green, pubescence sparse along the midrib and
veins or sometimes tufted in the axils; petioles slender, about
three-quarters of an inch long, pubescent on the upper surface,
reddish, usually with two glands at the base of the leaf-blade;
stipules linear, glandular, serrate.

Flowers appearing before or with the leaves, season of
blooming late, about three-quarters inch across, odor
sometimes disagreeable; borne on lateral spurs and buds, two
or four flowers in a cluster; pedicels one half inch long,
slender, glabrous; calyx-tube campanulate, glabrous, obscurely
nerved, about one-fourth length of the pedicel; calyx-lobes
as long as tube, ovate-oblong, obtuse at the apex, usually
glabrous outside, pubescent inside at least toward the base,
glandular-ciliate, erect; petals one-third inch long, white,
creamy in the bud, oval or obovate, margins slightly erose,
abruptly tapering into a claw, sometimes pubescent; stamens
about twenty in number, equal to or shorter than the petals;
filaments glabrous; anthers yellow or sometimes tinged red;
pistils glabrous shorter than the stamens.

Fruit ripening early; globose or oval, shortest diameter about
an inch, bright currant-red, rarely yellow; bloom thin; dots
few or numerous, whitish, large or small, always conspicuous;
cavity shallow, narrow; suture a line; apex rounded or slightly
depressed; flesh light to dark yellow, juicy, soft or melting,
fibrous, sweetish, sour at the pit, aromatic; good; stone
clinging to the flesh, varying from about one-half inch in
length in the wild fruits to at least three-quarters inch in
cultivated varieties, turgid, oval, prolonged and pointed at
the apex, usually obliquely truncate at the base, more or less
roughened, grooved on the dorsal edge, thick-margined and
markedly grooved on the ventral one.

The description of this species is based on both wild and cultivated material, and the variety Arkansas may be considered as a typical representative. Type specimens, deposited in the Economic Collection of the United States Department of Agriculture, were collected by W. F. Wight (flowers) at the New York State Experiment Station, Geneva, New York, No. 2721, May 15, 1909, and (foliage) at the Iowa Experiment Station, Ames, Iowa, No. 4178, September 15, 1909.

This species differs from _Prunus angustifolia_, with which it has long been confused, chiefly in being a much larger plant, a true tree while the other seldom reaches the size of a tree. It has coarser and less twiggy branches, shaggier bark and less red in the color of the young wood. The leaves are larger, thicker, more truly lanceolate in shape, less folded, a lighter green and less glossy. The flowers of the new species are larger, fewer in number, borne in less dense umbels which are not so nearly sessile as those of the older species and are borne on longer pedicels. The calyx-lobes are erect in this species and reflexed in _Prunus angustifolia_, strongly marked by marginal glands in _Prunus munsoniana_ and eglandular in _Prunus angustifolia_. The fruits are larger and wholly plum-like in the newly made species and cherry-like in _Prunus angustifolia_. The stone is very plum-like in _Prunus munsoniana_ but in the older species it might easily be mistaken for the pit of a cherry. The robust form is hardy as far north as Geneva, New York, at least, while the other species cannot be grown much north of Mason and Dixon’s line.

Of the varieties which certainly belong to this species by far the greatest number have originated under cultivation. There is herbarium material from uncultivated plants to show that this species is rather common in the northern part of Texas, in eastern Oklahoma and in parts of Missouri. It is a species forming dense thickets in its native habitat, where it is usually found in rather rich soils, with the older central specimens sometimes attaining a height of twenty to twenty-five feet and gradually diminishing in height to the edge of the thicket. When budded and grown in the orchard it forms a well-defined trunk and attains a height of twenty-five feet or more. The branches are little or not at all spinescent, bark of the stem in young specimens reddish or chestnut-brown, and usually rather smooth, becoming scaly and losing its reddish color with age, that of the young twigs usually chestnut-brown. Its natural range, though not yet definitely determined, probably extends from central Tennessee through northern Mississippi, northern Arkansas, central Missouri and southeastern Kansas to the valley of the Little Wichita River in northern Texas.

The Wild Goose varieties, now placed here, in the past have been considered hybrids more closely resembling _Prunus hortulana_ than any other species. But Wild Goose and some other varieties of its group are not to be distinguished from _Prunus munsoniana_ and beyond question belong in this species. The varieties in this division of Munsoniana are largely seedlings of Wild Goose, each variety possibly with a different male parent since Wild Goose seldom or never fruits unless cross-fertilized. Thus, of these plums, twelve are known seedlings of Wild Goose; seven others originated under cultivation; the origin of fourteen is not known and it is not certain that any beside Wild Goose came from wild plants. From such a record, and from the characters of the plants, it is probable that some of the Wild Goose varieties are horticultural hybrids, many of them from H. A. Terry of Iowa in whose work, with many varieties of several species, hybridity was the rule.

Horticulturally, this is the most important group of native plums for the South; it contains a greater number of cultivated varieties than any other native species excepting _Prunus americana_, no less than sixty sorts being listed in _The Plums of New York_, some of which are deservedly the best known of the native plums for either home or market use. For dessert or the kitchen they are particularly valuable, having a sprightly vinous flavor making them very pleasant flavored to eat out of hand or when cooked. Their bright colors, semi-transparent skins and well-turned forms make them very attractive in appearance. Considering the juiciness of most of the varieties, these plums ship and keep well. Unfortunately nearly all of the varieties of this species are clingstones. This group hybridizes more freely than any other of the plums and there are a great number of promising hybrids of which it is one of the parents. Of all plums, these are most in need of cross-pollination, some of the varieties being nearly or, as in the case of Wild Goose, wholly self-sterile. While these plums are especially valuable in the Southern States, some of them are desirable in the North as well, where all will grow at least as far north as central New York. Plums of this species are occasionally but not often used as stocks. Some recommend them for stocks for low or wet lands. The fact that _Prunus munsoniana_ suckers very badly will probably preclude its use largely in propagating.

The leading varieties under cultivation of this species are Arkansas, Pottawattamie, Robinson, Newman, Wild Goose and Downing, all of which are described in full and illustrated in colors in _The Plums of New York_. The first four of these have in the past been referred by botanists and pomologists to _Prunus angustifolia_ and the last two to _Prunus hortulana_.

=20.= =PRUNUS MARITIMA= Marshall

=1.= Marshall _Arbust. Am._ 112. 1785. =2.= Wangenheim _Amer._
103. 1787. =3.= Michaux _Fl. Bor. Am._ =1=:284. 1803. =4.= Pursh
_Fl. Am. Sept._ 332. 1814. =5.= Nuttall _Gen. N. Am. Pl._
=1=:302. 1818. =6.= Elliott _Sk. Bot. S. C. and Ga._ =1=:543.
1821. =7.= Torrey and Gray _Fl. N. Am._ =1=:408. 1840. =8.=
Torrey _Fl. N. Y._ =1=:194. 1843. =9.= Emerson _Trees of Mass._
449. 1846. =10.= Bailey _Cornell Sta. Bul._ =38=:75, fig. No.
9. 1892. =11.= Waugh _Vt. Sta. An. Rpt._ =12=:234. 1899. =12.=
Bailey _Cyc. Am. Hort._ 1449, fig. 1901.

_P. littoralis._ =13.= Bigelow _Fl. Bost._ Ed. =2=:193. 1824.

_P. pubescens._ =14.= Torrey _Fl. U. S._ 469. 1824.

_Cerasus pubescens._ =15.= Seringe _DC. Prodr._ =2=:538. 1825.
=16.= _Beck Bot. Nor. and Mid. U. S._ 96. 1833.

Shrub four to ten feet high, sometimes a low tree under
cultivation; main branches decumbent and straggling or upright
and stout; bark dark brown or reddish, more or less spiny,
often warty; branchlets slightly pubescent at first, becoming
glabrous, dark reddish-brown, straight or slightly zigzag and
rather slender; lenticels few, small, dark.

Winter-buds small, long, acute, with small reddish scales;
leaves oval or obovate, short-acute or nearly obtuse at the
apex, rounded or nearly acute at the base, margins closely and
evenly serrate, thinnish or thickish and somewhat leathery;
upper surface glabrous, dull green, lower surface paler and
more or less pubescent; petioles less than one-half inch long,
stout, tomentose or glabrous; glands two, sometimes more, at
the base of the leaves.

Flowers small, appearing before the leaves but the latest
of any of the hardy plums; borne in three-flowered umbels
closely set along the rigid branches; calyx-tube campanulate,
tomentose; petals white, sometimes pinkish, sub-orbicular,
narrowed into a claw at the base; pedicels short, slender,
stiff, tomentose.

Fruit maturing in late summer in Massachusetts; one-half inch
in diameter, globose, slightly flattened at the ends; cavity
shallow, borne on a slender pedicel more than one-half inch in
length, usually dark purple with a heavy bloom but variable,
sometimes red or less frequently yellow; skin thick, tough and
acrid; flesh crisp, juicy, sweetish; stone free from the flesh,
small, turgid, pointed at both ends, cherry-like, acutely
ridged on one and grooved on the other edge.

_Prunus maritima_, or as it has long been known, the Beach plum, is as yet hardly grown as a domesticated fruit. It is destined, however, in the minds of not a few, because of qualities which we shall describe, to play a more important part in the future of the cultivated plum flora than it has in the past. It has several valuable characters that should fit it alike for direct cultivation and for hybridizing with other species. It is surprising that more has not been done to domesticate the Maritima plums for they were among the first fruits noticed by early explorers and have always been used by both Indians and Whites for culinary purposes. The fact that Domestica plums thrive in their habitat is the only explanation of the non-amelioration of this plum before this.

September third, 1609, Hudson entered the river bearing his name and found “a very good harbor, abundance of blue plums, some currants brought by the natives dried and the country full of great and tall oaks.” The blue plum was the Maritima; and from Hudson’s time nearly all of the accounts of the New World given by early explorers mention this plum. It is probably one of the plums described by Captain John Smith as a cherry “much like a Damson;” by Edward Winslow in 1621, in a letter to England to a friend, as one of his “plums of three sorts”; by Francis Higginson in his _New England’s Plantation_ in 1630; described by Thomas Morton in 1632 in his _New English Canaan_ as having “fruit as bigg as our ordinary bullis.” John Lawson, one of the first of American naturalists, describes them rather more fully as follows:[140] “The American Damsons are both black and white, and about the Bigness of an European Damson. They grow any where if planted from the Stone or Slip; bear a white blossom, and are a good fruit. They are found on the Sand-Banks all along the Coast of America. I have planted several in my Orchard, that came from the Stone, which thrive well amongst the rest of my Trees. But they never grow to the Bigness of the other Trees now spoken of. These are plentiful Bearers.” These are but a few of the many references to the Beach plum but they are enough to show that the colonists were attracted by this wild plum found on a long stretch of the Atlantic seaboard—probably the first fruit to attract attention from Virginia to New England.

To be more explicit as to its range, _Prunus maritima_, in its typical form, is an inhabitant of the sea beaches and sand dunes from New Brunswick to the Carolinas, or possibly farther south, growing inland usually as far as recent ocean soil formations extend. As it leaves the seaboard marked variations make their appearance, chief of which are, smaller, more oval, smoother and thinner leaves and smaller fruit. The species has been reported as an inhabitant of the sands at the head of Lake Michigan,[141] but the writer, who is well acquainted with this region, has never seen it there, nor is it to be found in the chief herbaria of Michigan as having been collected in the state.

In the region where it is found wild the Maritima plum is a rather common article of trade. The fruit is usually sold by the quart, the price being five or ten cents, and is used for both dessert and culinary purposes though for most part for the latter.

The species is one of the most variable of the true plums and there is, probably must ever be, much disagreement as to its botanical relationships. Several botanical varieties of _Prunus maritima_ have already been named and there are yet groups within the species which seem to be nearly as distinct as those described and possibly worth distinguishing. Since the variations show in the size, color and edible qualities of the fruit, as well as in the characters of the plant, it is to be expected that the species has a horticultural future though at present it has but one cultivated variety—Bassett. Professor J. W. Macfarlane of the University of Pennsylvania has shown well the great range of variations in this plum both from botanical and horticultural aspects.[142] He holds that these variations are sufficiently distinct to make many varieties of this plum in the wild, to which DeVries agrees with the statement that they indicate “the existence of separate races as elementary species.”[143] The plum which Small has described as _Prunus gravesii_, to be discussed later, is a marked variation of _Prunus maritima_.

As it grows on the sea-coast _Prunus maritima_ is a low bush three to six feet high, occasionally reaching a height of ten or twelve feet. Usually the plant is straggling but sometimes it is compact or even tree-like. Inland, on better soils, or under cultivation it makes a rather handsome dwarf tree. The flowers are borne in great numbers, completely covering the plant and coming later than most of the plums bloom. The species bears fruit very abundantly, which is always attractive but of quite diverse value for food. The fruit varies in size from a half to three-quarters of an inch in diameter and is almost spherical, though sometimes oval and with or without a distinct suture. The usual color is a rich bluish-black with a waxy bloom, but red, yellow, amber and orange fruits are often found. In taste the Maritima plums range from inedible to nearly as rich a flavor as is found in the best of the Domestica plums. Besides variations in the above and other qualities, Macfarlane calls attention to the range in ripening of the fruit of this plum, showing that it extends over a period of two months, an exceptionally wide variation for a wild plant.

This plum has a number of qualities that commend it to the fruit-grower. Since in the wild it grows on sandy soils it is not likely under cultivation to make great demands on either the moisture or the fertility of soils. It is very hardy and very productive and seldom fails to bear. It seems to be free or nearly so from some of the pests of cultivated plums. Lastly, the great number of wild varieties of the plums give many starting points from which to breed cultivated varieties. Two objections to the wild fruits are that when the fruit is harvested the juice often exudes from the wound made by the parting from the stem, and secondly, the secretion of some substance forming a dark colored, hard core in the pulp which gives a very bitter taste to the fruit. The last defect is very common in the wild plums and is probably due to the sting of an insect. Under cultivation it may be possible to obtain fruits free from these faults.

It would be desirable if some of the characters enumerated above could be combined with those of other species. Burbank has hybridized the Maritima plum with other species, with promising results. Of these he writes under date of December 6, 1909, as follows:

“I first began raising _Prunus maritima_ about 1887—twenty-two
years ago—collecting myself and having specimens sent me
all the way from the coast of Labrador to South Carolina,
the finest of which were obtained from the eastern coast of
Massachusetts. Among the seedlings, of which I raised and
fruited several hundred thousands, were yellow, red, purple
and almost black ones, early and late, round, oval, oblate and
flattened, with big stones and little stones, free stone and
cling stone, and much variety in productiveness and growth
of the young bushes, but _not one of them_ the first two or
three generations were very much increased in size—probably
the largest being about the size of a cranberry or a small
hazelnut—and none of them of very exceptional quality, though
their habit of blooming late was a tremendous advantage, as
they invariably escaped our spring frosts. This, with their
unusual hardiness induced me to continue experimenting with
them. Finally after some ten years I obtained a very delicious
variety, about an inch in length and three-quarters of an
inch in diameter, tree much increased in size, larger foliage
and more productive and producing enormous quantities of most
delicious fruit. From this I raised a great many thousand,
almost as good and a few of them even _better_, several
hundred of which have been selected and are now bearing on my
Sebastopol place. Some of these improved seedling trees grow
five to ten times as large as the ordinary Maritima, with
larger leaves and in every possible way improved. My greatest
success with this species (and one of the most striking
occurrences in my work with plums) was produced by pollinating
one of the somewhat improved Maritimas with _Prunus triflora_.

“The very first generation, a plum was produced which is an
astonishing grower for a Maritima—almost equal to the Triflora,
with large, broad glossy foliage of almost the exact shape of
the Maritima, Maritima blossoms, and fruit weighing nearly
one-quarter of a pound each, with an improved superior Maritima
flavor, Maritima pit in form, but enlarged. The most singular
peculiarity of this plum, which is so enormous, is that the
trees commence to bloom about with the Triflora and bloom and
bear fruit all summer, so that blossoms, young fruit and the
enormous deep red ripening fruit can be seen on the trees at
the same time.”

=21.= =PRUNUS GRAVESII= Small

=1.= Small _Torrey Bot. Club Bul._ =24=:44, Pl. 292. 1897. =2.=
Britton and Brown _N. Am. Trees_ =2=:249. 1897. =3.= Robinson
and Fernald _Gray’s Man._ Ed. =7=:498. 1908.

Shrub low, slender, attaining a height of four feet; main
trunk much branched, with dark, rough bark; branches
ascending, slender, leafless, unarmed; branchlets of the
season puberulent. Leaves oval-orbicular, orbicular or
slightly obovate, rounded, retuse or apiculated at the apex,
base truncate or at least obtuse, margins sharply serrate or
crenate-serrate; upper surface sparingly pubescent or glabrous,
lower surface pubescent, especially on the veins.

Flowers white, one-half inch broad; borne in two or
three-flowered, lateral umbels, appearing with the leaves;
calyx-tube campanulate, pubescent; petals sub-orbicular,
abruptly narrowed at the base; pedicels stout, stiff, pubescent.

Fruit maturing in September; globose, one-half inch in
diameter, nearly black, with a light bloom, acid and
astringent; stone broadly oval, rounded at the apex, acute at
the base.

_Prunus gravesii_ is now known only in Connecticut, where it is found on a gravelly ridge at Groton near Long Island Sound. It grows in the neighborhood of _Prunus maritima_ to which it is evidently closely related. Small in describing the species gives the following differences between the Gravesii and the Maritima plums: (1) _Prunus gravesii_ is more slender and delicate in habit, and matures its leaves and fruit earlier in the season. (2) The leaf of _Prunus gravesii_ is small and sub-orbicular while that of the other is larger and more elongated. (3) The new species has smaller flowers with sub-orbicular petals while those of _Prunus maritima_ are broadly obovate and gradually narrowed at the base. (4) The fruit of _Prunus gravesii_ is smaller and more globose and has shorter pedicels. (5) The stone is more turgid and is pointed only at the base; that of _Prunus maritima_ is usually pointed at both ends. (6) Sprouts arising from the ground do not produce flowers as they frequently do in the case of _Prunus maritima_.

The cultivation of this plum has not been attempted and as compared with Maritima it promises little for the fruit-grower.

=22.= =PRUNUS ORTHOSEPALA= Koehne

=1.= Koehne _Deut. Dend._ 311. 1893. =2.= Sargent _Gar. and
For._ =7=:184, 187 fig. 1894. =3.= Bailey _Cyc. Am. Hort._
1450. 1901.

Shrub four or five feet high; branches dense and twiggy; stems
sometimes armed with slender spines; bark separating in large,
loose scales; branchlets stout, slightly zigzag, reddish-brown
becoming dark brown.

Winter-buds obtuse, three-lobed at maturity; leaves
oblong-ovate, thin and firm, acuminate, long-pointed, two and
one-half to three inches long, two-thirds inch broad, unequally
cuneate or rounded at the base; margins closely serrate with
incurved, calloused or rarely glandular teeth; upper surface
glabrous, light green, lower surface paler and pilose; petioles
slender, slightly grooved, puberulous, one-half inch long;
glands two, large, at the apex of the petiole.

Flowers appearing after the leaves; borne in three or
four-flowered fascicles on stout pedicels one-half inch
long; calyx-tube turbinate; lobes puberulous on the outer
surface, with thick tomentum, often tipped with red on the
inner surface; petals narrowly obovate, rounded at the apex,
narrowing at the base into slender claws, white or tinged with
pink; stamens orange, exserted; style glabrous, thickened at
the apex into a truncate stigma.

Fruit globose, an inch in diameter, deep red with a heavy
bloom; skin thick; flesh yellow, juicy, of good flavor; stone
flattened, oval, slightly rugose, deeply grooved on the dorsal
and ridged on the ventral edge.

The history and habitat of Orthosepala are given by Sargent as follows: “The history of this plant as I know it, is briefly this: In June, 1880, Dr. George Engelmann of St. Louis, sent to the Arnold Arboretum a package of seeds marked ‘Prunus, sp. southern Texas.’ Plants were raised from these seeds and in 1888, or earlier, they flowered and produced fruit, which showed that they belonged to a distinct and probably undescribed species. A name, however, was not proposed for it, and in 1888, probably, plants or seeds were sent to Herr Spath, of the Rixdorf Nurseries, near Berlin, where this plum was found in flower by Dr. Emil Koehne, who has described it under the name of _Prunus orthosepala_.”

Of the affinity of this species Sargent says: “_Prunus orthosepala_ is a true plum, rather closely related to _Prunus hortulana_, from which it can be distinguished by the smaller number of glands of the petioles, by the eglandular calyx-lobes, the dark colored fruit and smoother stone.” As the writer has seen this plum growing in the Arnold Arboretum, Jamaica Plains, Massachusetts, and the City parks at Rochester, New York, it seems well worth cultivating. Mr. J. W. Kerr writes of it as follows:

“I have _P. orthosepala_ fruiting here, and with me
its fruit is exceptionally fine in quality, sparingly
produced—attributable I believe to the fact that no variety
stands near enough to it for proper inter-pollination. The
trees are rather dwarfish in habit, close-headed, with fine
clean foliage. The fruit is globular in form; size equal to
fair specimens of Hawkeye or Wyant; skin a greenish-yellow,
almost entirely covered with deep red.”

W. F. Wight of the United States Department of Agriculture has collected specimens of a cultivated plum, taken from the wild, locally known as the Laire, in Rooks and neighboring counties in Kansas, with foliage very similar to _Prunus orthosepela_. While the identity of Laire with the species under discussion cannot be established at this time, the reported source of the seeds, “southern Texas,” from which _Prunus orthosepela_ was grown may be an error.

=23.= =PRUNUS GRACILIS= Engelmann and Gray

=1.= Engelmann and Gray _Bost. Jour. Nat. Hist._ =5=:243. 1845.
=2.= Torrey _Pac. R. Rpt._ =4=:83. 1854. =3.= Britton and Brown
_Ill. Fl._ =2=:249, fig. 1897.

_P. chicasa_ var. _normalis._ =4.= Torrey and Gray _Fl. N. Am._
=1=:407. 1840.

_P. normalis_ =5.= Small _Fl. S. E. U. S._ 572. 1903.

Shrub low, attaining a height of five or six feet; branches
many, straggling, more or less spiny; branchlets at first
densely tomentose or soft-pubescent, becoming glabrous; leaves
small, ovate-lanceolate or oval, margins finely and evenly
serrate, rather thick, texture harsh and firm; upper surface
dark green, glabrous or nearly so at maturity, lower surface
paler, soft-pubescent becoming nearly glabrous; petiole short
and stout.

Flowers white, small, appearing before the leaves; borne in
sessile, several-flowered umbels; pedicels short, slender,
soft-pubescent.

Fruit globose or oval, very small, not more than one-half inch
in diameter, variable in color, mostly in shades of red; stone
turgid, nearly orbicular, pointed at both ends.

_Prunus gracilis_ is found in dry, sandy soils from southern Kansas and western Arkansas to central Texas. It grows most abundantly and thrives best in Oklahoma, a fact which leads Waugh to call it the “Oklahoma” plum. All who know the species agree that it is a near approach to Maritima in many of its characters. This plum is very variable and some of its forms seem not to have been well studied. As a fruit plant Gracilis is hardly known in cultivation though Torrey says it is cultivated in the region of its habitat under the name Prairie Cherry. The wild fruit is used more or less locally and is sometimes offered for sale in the markets of western towns. The quality is about the same as that of the wild Americanas and under cultivation would probably improve. The small size of plant and fruit are the most unpromising characters though the species is also much subject to black-knot.

=24.= =PRUNUS RIVULARIS= Scheele

=1.= Scheele _Linnaea_ =21=:594. 1848. =2.= Gray _Pl. Wright._
=1=:67. 1852. =3.= Hall _Pl. Texas._ 9. 1873. =4.= _Coulter
Cont. U. S. Nat. Herb._ =2=:101. 1891. =5.= Waugh _Bot. Gaz._
=26=:50-52. 1898. =6.= Bailey _Ev. Nat. Fr._ 223. 1898.

Shrub three to seven feet high; branches angular, smooth,
shining, ash-colored, rough; lenticels small, crowded;
leaves oblong-ovate or sometimes ovate, rarely lanceolate,
apex acute, margins coarsely or doubly serrate, glabrous
above and sparingly pubescent below; petioles glandular,
grooved, pubescent; flowers in lateral umbels, in pairs or
several-flowered; fruit about one-half inch in diameter,
oblong-oval, cherry-red; skin thick, smooth and tough, acid.

The preceding description is largely compiled from the authors given in the references, the writer having seen only herbarium specimens. The species is included here largely upon the authority of Professor C. S. Sargent of the Arnold Arboretum and W. F. Wight, who know the plant as described by Scheele in the field. Gray described the plant as “verging to Americana.” Bailey says “it evidently bears the same relation to _Prunus americana_ that _Prunus watsoni_ does to the Chickasaw plum.” Waugh is “convinced that _Prunus rivularis_ Scheele is nothing more than one of the more distinct sub-divisions of the multiform _hortulana_ group.”[144] T. V. Munson writes me that the Waylandi plums belong in this species. My own opinion is, from the herbarium specimens examined, from correspondence and conversation with those who have seen the plant in the field, that Scheele’s species is a good one and quite distinct from the species named by Bailey, Waugh and Munson as allied to it. It is to be looked for along the streams and bottom-lands in the neighborhood of San Antonio and New Braunfels, Texas. The plum is locally known as the Creek plum and in common with other plums is gathered for home consumption. The species seems to offer but few possibilities for the fruit-grower.