254 



DRUPACEAE. 



[VOL. II. 



x. Amygdalus Persica L,. Peach. 

 (Fig. 2027.) 



Amygdalus Persica L. Sp. PI. 472. 1753. 



A small tree, the purplish-brown twigs gla- 

 brous. Leaves mostly lanceolate or oblong-lan- 

 ceolate, 3'-5' long, 8 // -i8 // wide, glabrous on 

 both sides, long-acuminate at the apex, usually 

 narrowed at the base, finely serrulate nearly all 

 around, thickish; petioles i"-$" long; flowers 

 pink, YZ'-I' broad, scaly-bracted; drupe subglo- 

 bose, grooved, softly velvety, i#'-3' in diameter. 



Escaped from cultivation, southern New York to 

 North Carolina. April-May. 



Family 46. MIMOSACEAE Reichenb. Fl. Exc. 437. 1832. 



MIMOSA FAMILY. 



Herbs, shrubs or trees, with alternate mostly compound, commonly 2-3-pin- 

 nate leaves, the stipules various, and small regular perfect flowers in heads, 

 spikes or racemes. Calyx 3-6-toothed, or 3-6-lobed, the teeth or lobes mostly 

 valvate in the bud. Corolla of as many distinct or more or less united petals, 

 also valvate. Stamens as many as the petals, or twice as many, or oo, distinct, 

 or monadelphous. Ovary i -celled; ovules several or numerous; style simple. 

 Fruit a legume. Seeds without endosperm ; cotyledons fleshy. 



About 30 genera and 1350 species, mostly of tropical distribution, a few in the temperate zones. 

 This, and the three following: families, are often united under the name I.EGUMINOSAE. 

 Stamens numerous, at least more than 10. i. Acacia. 



Stamens only as many as the petals, or twice as many. 



Petals separate; pod smooth. 2. Acuan. 



Petals united to about the middle; pod spiny. 3. Morongia. 



i. ACACIA Adans. Fam. PI. 2: 319. 1763. 



Shrubs or trees, some species nearly herbaceous, with bipinnate leaves, the ultimate leaf- 

 lets usually small and numerous, or the leaves in many exotic species modified into flat 

 simple phyllodes. Flowers small, in heads or spikes. Calyx campanulate, usually 4-5 

 toothed, or of 4 or 5 distinct sepals. Petals mostly 4 or 5, separate, united, or wanting. 

 Stamens oo, exserted; filaments filiform; pollen-grains cohering in 2's-o's. Ovary sessile 

 or stipitate. Pod linear, oblong or oval, flat or swollen, often constricted between the seeds. 

 [Greek, point, or thorn, many species being thorny.] 



About 450 species, chiefly in subtropical regions, most abundant in Africa and Australia, a few 

 in the temperate zones. Besides the following, some 15 others occur in the southern United States. 



i. Acacia filiculoides (Cav.) Trelease. Prairie Acacia. (Fig. 2028.) 



Mimosa filiculoides Cav. Ic. x: 55. pi, 78. 1791. 



Acacia filicina Willd. Sp. PI. 4: 1072. 1806. 



Acacia filiculoides Trelease; Branner & Coville, Rep. 



Geol. Surv. Ark. 1888: Part 4, 178. 1891. 



A thornlcss shrub, varying from glabrous to hir- 

 sute-pubescent, sometimes herbaceous. Pinnae of 

 the leaves 2-15 pairs, oblong in outline, \'-i' long; 

 leaflets 10-50 pairs, oblong or linear-oblong, about 

 i" long, less than i" wide, obtuse or acute, slightly 

 inequilateral, i-veined; heads globose, many-flow- 

 ered, axillary, slender-peduncled, 6 // -io // in dia- 

 meter; sepals distinct or nearly so; filaments yel- 

 low, 3-4 times as long as the sepals; pod linear, 

 acute, often narrowed at the base, stipitate, mostly 

 straight, i / -2 / long, about 3" wide, flat, its valves 

 thin, reticulated, glabrous or pubescent, impressed 

 between the seeds. 



Prairies, Missouri and Kansas to Texas, Arizona and 

 Mexico. May-July. 



