5. ACA'CIA, Necker. (Gr. to sharpen; alluding to the spines.) Flowers polygamous; calyx valvate, 4 to 5-toothed; petals 4 or 5, united below, rarely distinct; stamens 8 to 200; legume continuous, not jointed, dry, 2-valved, many-seeded. - Trees, shrubs or herbs, spineless, or with stipular spines. Lvs. (in the N. Am. species) bipinnate. Fls. in heads or spiked. (This is a large and ornamental genus of chiefly tropical plants, much cultivated in the greenhouse. In many of them the leaflets disappear and phyllodia (§ 307) take their places.)
1 A. lutea Leav. Prostrate, herbaceous, minutely strigous; stip. lance-subulate; pinnce 3 to 5 pairs, lfts. 12 to 20 pairs, very small (2" long); hds. oblong-cylindric, the peduncles longer than the leaves; fls. yellow, decandrous; pods broad and flat, obtuse, about 6-seeded, and raised on a slender stipe. - Prairies Fla., La. and Ala. Its herbage much resembles Mimosa strigillosa, except the stipules. Pods 1 to 2' long, 8" wide, the stipe about 6". Lvs. ciliate, sensitive, with no glands.
2 A. Julibrassin Willd. Tret glabrous, unarmed; pinna 8 to 12 pairs, lfts. 20 to 30, halved, acute, inequilateral: gland depressed at the base of the petiole; hds. pedunculate, forming a terminal panicle; stam. numerous, long, exserted. - A very ornamental tree cultivated and sparingly naturalized in the Gulf States. Corollas white, with purplish stamens. Pods large, pointed at both ends, contracted between the seeds.
6. GTMNOC'LADUS, Lam. Coffee Tree. (Gr. naked, a shoot; for its coarse, naked shoots in winter.) Flowers
Calyx tubular, 5-cleft, equal; petals 5, inserted into the summit of the tube; stamens 10, distinct.? Calyx and corolla as above; style 1; legumes l-celled, oblong, very large, pulpy within. - A slender, unarmed tree, with unequally bipinnate lvs. Lfts. ovate, acuminate.
G. Canadensis Lam. Grows in Western N. Y., Ohio, Ind. S. to Tenn., on the borders of lakes and rivers. Height 50f, with a trunk 15' diam., straight and simple to the height of 25f, covered with a rough, scaly bark, and supporting a rather small but regular head. The compound lvs. are 2 to 3f long, and 15 to 20' wide, being doubly compounded of a great number of dull green leaflets. Single leaflets often occupy the place of some of the pinnae. Fls. greenish-white, in long racemes, succeeded by very large curved pods containing each several round, depressed, brown, polished, and very hard seeds. May - Jl.
7. GLED'TS'CHIA, L. Honey Locust. (For John G. Gleditsch, a botanical writer, Leipzig.) Flowers . Sepals equal, 3 to 5, united at base; petals 3 to 5; stamens 3 to 5, distinct, opposite the sepals, sometimes by abortion fewer or 0; style short, often abortive; legume continuous, compressed, often intercepted between the seeds by a quantity of sweet pulp. - Trees, with supra-axillary, branched spines. Lvs. abruptly pinnate and bipinnate, often in the same specimen. Fls. small, green, racemous.
1 G. triacanthus L. Branches armed with stout, triple spines; lfts. alternate, oblong-lanceolate, obtuse; leg. linear-oblong, compressed, many-seeded, intervals filled with sweet pulp. - Penn. to Mo. and La. In favorable circumstances it attains the height of 70f, undivided half its length, with a diameter of 3 to 4f. The thorns are 2 to 12' long, ligneous, numerously branched, forming horrid masses along the trunk. Foliage light and elegant. Lfts. about 18, 1 to 1 1/2' long, 1/3 as wide, 1, 2 or 3 of them frequently transformed, either partly or wholly, into smaller leaflets (§ 290). Fls. succeeded by flat, twisted, hanging pods 12 to 18' long, of a dull red. Sds. flat, hard, brown, imbedded in a fleshy substance, at first sweet, but becoming sour. Jn. - The wood is very heavy.
2 G. monosperma Walt. Water Locust. Armed with few, slender, mostly simple spines; lfts. ovate-oblong; leg. broadly oval, without pulp, one-seeded.- Swamps, S. Car. to Fla. and La., not common. A tree of smaller dimensions than the former, with a smoother bark. Pods about 2' long with the stipe, 1' wide. Fls. greenish, in ament-like racemes like the other. Jn.
8. CAS'SIA, L. Senna. (Hebrew, Katzioth.) Sepals 5, scarcely united at base, nearly equal; petals 5, unequal, but not papilionaceous; stamens distinct, 10, or by abortion fewer, anthers opening by terminal • pores, the three upper often sterile; legume many-seeded, l-celled or many-celled transversely. - Trees, shrubs or herbs. Lvs. simply, abruptly pinnate.
§ Stam. 5 or 10, all perfect Sepals acute. Lfts. small......................................
Nos. 1, 2
§ Stam. 10, the 3 upper abortive. Sep. obtuse. Lfts. large. (a)
a Gland on the petiole at or near the base.............................
Nos. 8, 4
a Gland on the rachis between the two lowest leaflets...........
Nos. 5, 6
1 C. Chamaecrista L. Sensitive Pea. Lfts. 8 to 12 pairs, oblong-linear, obtuse, mucronate; fls. large, pediciliate, 2 or 4. in each fascicle; anth. 10, unequal, all fertile. - An elegant plant in dry soils, Mass., Mid., W. and S. States. St. 1/2 to 2f high, round, pubescent. Lfts. crowded, 4 to 8" by 1 to 2 1/2", smooth, subsessile. Fls. 15 to 18" broad. Bracts lance-subulate, as are also the stipules, persistent. Petals bright yellow, the 2 upper ones with a purple spot. Aug. - The leaves possess considerable irritability.
2 C. nictitans L. Wild Sensitive Plant. Lfts. 6 to 15 pairs, oblong-linear, obtuse, mucronate, sessile; fls. small, 2 or 3 in each subsessile fascicle; sta. 5, subequal. - In dry, sandy soils, Mass. to La. St. about 1f long, slender, branching. Lfts. crowded, 4 to 6" by 1 to 2". The petiolar gland, as in No. 1, placed 2 or 3" below the lowest pair of leaflets. Fls. very small (5" broad), pale yellow, on short pedicels. Jl. - The leaves are quite sensitive, closing by night and when touched.