332 



MIMOSACEAE. 



Vol. II. 



I. Acuan leptoloba (T. & G.) Kuntze. 

 Prairie Mimosa. Fig. 2431. 



Desmanthus leptolobus T. & G. Fl. N. A. i : 402. 1840. 

 Acuan leptoloba Kuntze, Rev. Gen. PI. 158. 1891. 



Herbaceous, ascending, branched, stems rough- 

 angled, 2°-3° long. Leaves short-petioled, bipinnate; 

 pinnae 5-10 pairs, sessile; leaflets 10-24 pairs, sessile, 

 linear-lanceolate, acute, inequilateral, rounded at the 

 base, usually glabrous, ii"-2" long, i" wide or less; 

 peduncles 6"-i2" long, few-flowered; stamens 

 (always?) 5; pods 3-8, narrowly linear, acuminate, 

 nearly straight, glabrous, about 3 times the length 

 of the peduncle, 6-8-seeded. 



Prairies, Kansas to Texas. Summer. 



2. Acuan illinoensis (Michx.) Kuntze. 

 Illinois Mimosa. Fig. 2432. 



Mimosa illinoensis Michx. Fl. Bor. Am. 2 : 254. 



1803. 

 Acacia brachyloba Willd. Sp. PI. 4: 1071. 1806. 

 Desmanthus brachylobus Benth. in Hook. Journ. 



Bot. 4 : 358. 1842. 

 A. illinoensis Kuntze, Rev. Gen. PI. 158. 1891. 



Ascending or erect, glabrous or nearly so, 

 stems angled, l°-3° high. Foliage resembling 

 that of the preceding species, but the pinnae 

 and obtusish leaflets are sometimes more 

 numerous; peduncles i'-2' long; pods nu- 

 merous, densely capitate, oblong or lanceo- 

 late, strongly curved, 8"-i2" long, acute, slightly 

 impressed between the 2-5 seeds. 



Prairies and river-banks, Ohio to Kentucky, 

 Florida, South Dakota, Colorado, Texas and New 

 Mexico. Illinois acacia. May-Sept. 



4. PROSOPIS L. ]\Iant. i: lo. 1767. 



Trees or shrubs often with spines in the axils, with 2-pinnate leaves, the leaflets few or 

 numerous, and small spicate or capitate perfect flowers. Calyx campanulate, with 5 short 

 teeth. Petals S, valvate, distinct, or connate below. Stamens 10, distinct ; filaments long. 

 Ovary often stalked, many-ovuled; styles slender or filiform; stigma very small. Pod linear, 

 straight or curved, compressed, leathery, indehiscent, the mesocarp spongy or dry. Seeds 

 flattened. [Ancient name for some very different plant.] 



About 15 species, natives of warm and tropical regions. Besides the following, 2 or 3 others 

 occur in the southwestern United States. Type species: Prosopis spicigera L. 



