Vou. II.] MIMOSA FAMILY. 255 
2. ACUAN Med. Theod. Sp. 62. 1786. 
[DEsSMANTHUS Willd. Sp. Pl. 4: 1044. 1806.] 
[DaRLIncTonia DC, Ann. Sci. Nat. 4:97. 1825.] 
Perennial herbs or shrubs, with bipinnate leaves, small stipules, and greenish or whitish 
small regular flowers in axillary peduncled heads or spikes. Flowers perfect, sessile, or the 
lowest sometimes staminate, neutral or apetalous. Calyx campanulate, its teeth short. 
Petals valvate, distinct, or slightly united or coherent below. Stamens 10 or 5, distinct, 
mainly exserted; anthers all alike. Ovary nearly sessile; ovules ©. Pod linear, straight or 
curved, acute, glabrous, flat, several-seeded, 2-valved, the valves coriaceous or membranous. 
About ro species, natives of warm and tropical America, one of them widely distributed in 
tropical regions of the Old World. 
Pods few, linear, erect, straight. 1. A. leptoloba. 
Pods numerous in globose heads, oblong, curved. 
2. A. Illinoensis, 
1. Acuan leptoloba (T. & G.) Kuntze. 
Prairie Mimosa. (Fig. 2029.) 
Desmanthus leptolobus T. & G. Fl. N. A. 1: 402. 1840. 
Acuan leptoloba Kuntze, Rev. Gen. Pl. 158. 1891. 
Herbaceous, ascending, branched, stems rough- 
angled, 2°-3° long. Leaves short-petioled, bipin- 
nate; pinnae 5-10 pairs, sessile; leaflets 10-24 
pairs, sessile, linear-lanceolate, acute, inequilateral, 
rounded at the base, usually glabrous, 1%4//—2// 
long, %4’’ wide or less; peduncles 6’/-12’ long, few- 
flowered; stamens (always?) 5; pods 3-8, narrowly 
linear, acuminate, nearly straight, glabrous, about 
3 times the length of the peduncle, 6-S-seeded. 
Prairies, Kansas to Texas. Summer. 
2. Acuan Illinoénsis (Michx. ) 
Kuntze. IllinoisMimosa. (Fig. 2030. ) 
Mimosa Illinoensis Michx. Fl. Bor. Am, 2: 254. 
1803. 
Acacia brachyloba Willd. Sp. Pl. 4: 1071. 1806. 
Desmanthus brachylobus Benth. in Hook. 
Journ. Bot. 4: 358. 1842. 
Acuan Illinoensis Kuntze, Rev. Gen. Pl. 158. 
1891. 
Ascending or erect, glabrous or nearly so, 
stems angled, 1°-3° high. Foliage resem- 
bling that of the preceding species, but the 
pinnae and obtusish leaflets are sometimes 
more numerous; peduncles 1/—3/ long; pods 
numerous, densely capitate, oblong or lanceo- 
late, strongly curved, 8/’’-12/ long, acute, 
slightly impressed between the 2-5 seeds. 
Prairies and river-banks, Indiana to Kentucky, 
Florida, Minnesota and Texas. May-Sept. 
3. MORONGIA Britton, Mem. Torr. Club, 5: 191. ~—-1894. 
[SCHRANKIA Willd. Sp. Pl. 4: 1041. 1806. Not Medic. 1792. ] 
[Leprociorris DC. Mem. Leg. 451. 1823?] 
Perennial herbs, or shrubs, mainly prostrate or procumbent, armed with recurved 
prickles. Leaves bipinnate, usually sensitive; leaflets numerous, small; stipules setaceous. 
Flowers regular, small, 4-5-parted, pink or purple, perfect or polygamous, in axillary pe- 
duncled heads or spikes. Petals united to the middle, Stamens usually 8-12, distinct or 
united at the base; anthers all alike. Ovary nearly sessile; ovules. Pod linear, acute or 
acuminate, spiny all over, at length 4-valved, several seeded. [Named in honor of the late 
Rey. Thos. Morong, a contributor to this work. ] 
About to species, natives of warm and tropical America, 1 in tropical Africa. 
Leaflets elliptic, strongly veined. _ 1. M. uncinata. 
Leaflets linear-oblong, scarcely veined. 2. M. angustata, 
