Flowers diœcious or polygamous, regular. Calyx elongated-tubular below, 5-cleft. Petals 5, oblong, equal, inserted on the summit of the calyx-tube. Stamens 10, distinct, short, inserted with the petals. Pod oblong, flattened, hard, pulpy inside, several seeded. Seeds flattish.—A large tall tree, with rough bark, stout branchlets, not thorny, and large unequally twice-pinnate leaves; the leaflets standing vertically.—Flowers whitish, in terminal racemes. (Name from γυμνός, naked, and κλάδος, a branch, alluding to the stout branches destitute of spray.)
1. G. Canadénsis, Lam. Leaves 2–3° long, with several large partial leafstalks bearing 7–13 ovate stalked leaflets, the lowest pair with single leaflets; stipules wanting; pod 6–10´ long, 2´ broad; the seeds over ½´ across.—Rich woods, western N. Y. and Penn. to Minn., E. Neb., and Ark.
44. GLEDÍTSCHIA, L. Honey-Locust.
Flowers polygamous. Calyx short, 3–5-cleft, the lobes spreading. Petals as many as the sepals and equalling them, the 2 lower sometimes united. Stamens 3–10, distinct, inserted with the petals on the base of the calyx. Pod flat, 1–many-seeded. Seeds flat.—Thorny trees, with abruptly once or twice pinnate leaves, and inconspicuous greenish flowers in small spikes. Thorns above the axils. (Named in honor of J. G. Gleditsch, a botanist contemporary with Linnæus.)
1. G. triacánthos, L. (Three-thorned Acacia, or Honey-Locust.) Thorns stout, often triple or compound; leaflets lanceolate-oblong, somewhat serrate; pods linear, elongated (1–1½° long), often twisted, filled with sweet pulp between the seeds.—Rich woods, western N. Y. and Penn. to Ga., west to Mich., E. Neb., Kan., and La. A large tree, common in cultivation, with very hard and heavy wood.
2. G. aquática, Marsh. (Water-Locust.) Thorns slender, mostly simple; leaflets ovate or oblong; pods oval, 1-seeded, pulpless. (G. monosperma, Walt.)—Deep swamps, Mo. to S. Ind., S. Car., and southward. A smaller tree, 30–40° high.
45. DESMÁNTHUS, Willd.
Flowers perfect or polygamous, regular. Calyx campanulate, 5-toothed. Petals 5, distinct. Stamens 5 or 10. Pod flat, membranaceous or somewhat coriaceous, several-seeded, 2-valved, smooth.—Herbs, with twice-pinnate leaves of numerous small leaflets, and with one or more glands on the petiole, setaceous stipules, and axillary peduncles bearing a head of small greenish-white flowers. (Name composed of δέσμα, a bond, and ἄνθος, flower.)
1. D. brachýlobus, Benth. Nearly glabrous perennial, erect (1–4° high); pinnæ 6–15 pairs; leaflets 20–30 pairs; peduncles 1–3´ long; stamens 5; pods numerous in dense globose heads, oblong or lanceolate, curved, scarcely 1´ long, 2–6-seeded.—Prairies and alluvial banks, Ind. and Ky. to Minn., Mo., and Tex.; also in Fla.
2. D. leptólobus, Torr. & Gray. Pinnæ 5–8 pairs; leaflets 10–20 pairs; peduncles 1´ long or less; heads rather loose, stamens 5; pods usually few, narrowly linear, erect, 1–2´ long.—Central Kan. to Tex.
46. SCHRÁNKIA, Willd. Sensitive Briar.
Flowers polygamous, regular. Calyx minute, 5-toothed. Petals united into a funnel-form 5-cleft corolla. Stamens 10–12, distinct, or the filaments united at base. Pods long and narrow, rough-prickly, several-seeded, 4-valved, i.e., the two narrow valves separating on each side from a thickened margin.—Perennial herbs, nearly related to the true Sensitive Plants (Mimosa); the procumbent stems and petioles recurved-prickly, with twice-pinnate sensitive leaves of many small leaflets, and axillary peduncles bearing round heads of small rose-colored flowers. (Named for F. P. Schrank, a German botanist.)
1. S. uncinàta, Willd. Prickles hooked; pinnæ 4–6 pairs; leaflets elliptical, reticulated with strong veins beneath; pods oblong-linear, nearly terete-short-pointed, densely prickly (2´ long).—Dry sandy soil, Va. to Fla., west to S. Ill., Kan., and Tex.
2. S. angustàta, Torr. & Gray. Leaflets oblong-linear, scarcely veined; pods slender, taper-pointed, sparingly prickly (about 4´ long).—S. Va. (?) to Fla., Tenn., and Tex.
Order 33. ROSÀCEÆ. (Rose Family.)
Plants with regular flowers, numerous (rarely few) distinct stamens inserted on the calyx, and 1–many pistils, which are quite distinct, or (in the last tribe) united and combined with the calyx tube. Seeds (anatropous) 1–few in each ovary, almost always without albumen. Embryo straight, with large and thick cotyledons. Leaves alternate, with stipules, these sometimes caducous, rarely obsolete or wanting.—Calyx of 5 or rarely 3–4–8 sepals (the odd one superior), united at the base, often appearing double by a row of bractlets outside. Petals as many as the sepals (rarely wanting), mostly imbricated in the bud, and inserted with the stamens on the edge of a disk that lines the calyx tube. Trees, shrubs, or herbs.—A large and important order, almost destitute of noxious qualities, and producing the most valuable fruits. Very intimately connected with Leguminosæ on one hand, and with Saxifragaceæ on the other.
I. Ovary superior and not enclosed in the calyx tube at maturity.
[*] Calyx deciduous, without bractlets, pistil solitary, becoming a drupe.
Tribe I. PRUNEÆ. Trees or shrubs, with simple mostly serrate leaves. Ovules 2, pendulous, but seed almost always solitary. Style terminal.
1. Prunus. Flowers perfect. Lobes of calyx and corolla 5. Stone of the drupe bony.
[*][*] Calyx mostly persistent; pistils few to many (rarely solitary).
[+] Calyx without bractlets; ovules 2–many.
Tribe II. SPIRÆEÆ. Pistils mostly 5, becoming 2–several seeded follicles. Shrubs or perennial herbs.
a. Calyx short, 5 cleft. Petals obovate, equal.
2. Spiræa. Flowers perfect or diœcious. Pods 1-valved. Herbs or shrubs; leaves simple or pinnate.
3. Physocarpus. Pods inflated, 2-valved. Shrub; leaves palmately lobed.
b. Calyx elongated, 5-toothed. Petals slender, unequal.
4. Gillenia. Herbs; leaves 3-foliolate.
Tribe III. RUBEÆ. Pistils several or numerous, becoming drupelets in fruit. Ovules 2 and pendulous, but seed solitary. Perennials, herbaceous or with biennial soft-woody stems.
5. Rubus. Pistils numerous, fleshy in fruit, crowded upon a spongy receptacle.
6. Dalibarda. Pistils 5–10 in the bottom of the calyx, nearly dry in fruit.
[+][+] Calyx lobes mostly with bractlets; ovule solitary.
Tribe IV. POTENTILLEÆ. Pistils few–many, 1-ovuled, becoming dry achenes. Herbs.
a. Styles persistent and elongated after anthesis, often plumose or jointed.
7. Geum. Calyx lobes usually with 5 alternating small bractlets. Stamens and carpels numerous, styles becoming plumose or hairy tails, or naked and straight or jointed.
b. Styles not elongated after anthesis, mostly deciduous.
8. Waldsteinia. Petals and calyx lobes 5; small or no bractlets. Stamens numerous. Achenes 2–6; styles deciduous from the base.
9. Fragaria. Flower as in Potentilla. Receptacle much enlarged and pulpy in fruit.
10. Potentilla. Petals 5 (rarely 4) conspicuous. Calyx lobes as many, with an alternating set of bractlets. Stamens and achenes numerous; the latter heaped on a dry receptacle. Styles commonly more or less lateral, deciduous or not enlarging in fruit.
11. Sibbaldia. Petals minute; stamens and achenes 5–10; otherwise as Potentilla.
II.