582 MIMOSACEAE 



nently nerved : peduncles surpassing the subtending bracts : pods linear, 3-6 cm. long, 

 curved, mostly unarmed, the segments often 5-8. 

 In dry soil, Texas and New Mexico. 



4. Mimosa Tezana (A. Gray) Small. A low rigidly branched shrub, with finely 

 pubescent or puberulent foliage, armed with subaxillary spines, the branches zigzag. 

 Leaves inconspicuous, with 4-6 approximate pinnae, or rarely only a pair, the rachis 

 pubescent ; leaflets usually 8-14, the blades oblong, 2-4 mm. long, veiny, ciliolate : pedun- 

 cles becoming 1-2 cm. long : pods broadly linear, 2-3 cm. long, not constricted between 

 the seeds, but well armed around the margin. 



On plains and prairies, Texas to New Mexico and adjacent Mexico. 



5. Mimosa Lindheimeri A. Gray. A puberulent shrub or small tree, armed with 

 flattened spines beside and slightly below the axils, the branches zigzag. Leaves numer- 

 ous, with 8-12 pinnae ; leaflets 16-24, the blades oblong, 2-3 mm. long: peduncles shorter 

 than the subtending bracts : spikes globose, fully 1 cm. in diameter : pods linear, curved, 

 2-4 cm. long, 3-4-jointed, glabrous, the margins armed with recurved prickles. 



In dry soil, western and southern Texas. 



6. Mimosa malacophylla A. Gray. A shrubby climber, with stems and branches 

 1-5 mm. long, armed with recurved prickles, tomentose. Leaves numerous, with 8-14 

 pinnae ; leaflets relatively few, the blades oval to obovate, 6-16 mm. long, more or less 

 oblique, rounded or apiculate at the apex : peduncles 1-1.5 cm. long: spikes oblong, 1.5 

 cm. long, white or yellowish : pods broadly linear, 5-7 cm. long, curved, 6-8-jointed, 

 glabrous, veiny. 



In dry soil, Texas to New Mexico and Nuevo Leon. The form with merely puberulent stems and 

 branches and rather larger glabrous leaflets is M. malacophylla glabrdta Benth. 



7. Mimosa Berlandidri A. Gray. A sparingly strigose upright shrub, with sparingly 



Srickle-armed branches. Leaves 3-6 cm. long, with 8-12 pinnae ; leaflets numerous, 

 0-80, the blades linear or linear-oblong, 4-5 mm. long, acute : peduncles shorter than 

 the subtending bracts: spikes oblong or ovoid, 12-14 mm. long: pods linear-oblong, 

 slightly curved, 4-9 cm. long, with 8-15 joints, rough -pubescent, each narrowed into a 

 short stipe. 



In low ground, southern Texas to San Luis Potosi. 



8. Mimosa Btrigillosa T. & G. A perennial herb, with radially prostrate often creep- 

 ing branches, the foliage more or less densely pubescent with rigid strigose hairs : leaves 

 numerous, with 10-16 pinnae ; leaflets 20-28, the blades oblong or linear-oblong, 4-6 mm. 

 long, obtuse or acutish, reticulated : peduncles surpassing the leaves : spikes pink, oblong, 

 1.5-2.5 cm. long: pods oblong or oval, 1-3 cm. long, 1-4-jointed, hispid, very oblique at 

 the apex. 



On river banks and in moist soil, chiefly near the coast, Florida to Texas. 



12. NEPTUNIA Lour. 



Perennial herbs or shrubby plants, with unarmed prostrate or diffuse stems, or some- 

 times floating. Leaves with 2-pinnate blades : leaflets relatively small. Flowers perfect 

 or polygamous, in head-like or cylindric spikes on solitary axillary peduncles. Calyx 

 5-lobed. Corolla of 5 distinct or partially united petals. Stamens 10, or rarely 5, 

 exserted : filaments distinct. Ovary stipitate. Ovules several. Pod relatively broad, flat, 

 oblique, 2-valved. 



Spikes about 50-flowered, oblong-cylindric. 1. N. lutea. 

 Spikes about 20-flowered, ovoid or oval. 

 Bracts and calyx-lobes ciliolate. 



Pinnae 4-6 : leaflets merely ciliolate. 2. N. pubescent. 



Pinnae 6-10: leaflets ciliolate and pubescent beneath. 3. N. Lindheimeri. 



Bracts and calyx-lobes not ciliolate. 4. N. Floridana. 



1. Neptunia lutea ( Leaven w.) Benth. Stems branched at the base, the branches 

 prostrate, 5-15 dm. long, somewhat shaggy pubescent, usually branching : leaves with 

 6-10 pinnae ; leaflets 18-34, the blades crowded, oblong, apiculate, ciliate, prominently 

 nerved beneath : stipules ovate-lanceolate : peduncles finally longer than the subtending 

 bracts : spikes oblong, 1-2 cm. long, usually nodding : pods oblong, 2-4 cm. long, flat, 

 abruptly pointed, contracted into a rather slender stipe often 8 mm. long : seeds 3-9. 



In moist or clay soil, Arkansas and the Indian Territory to Florida and Texas. Spring and sum- 

 mer. A Texan form with nearly or quite glabrous branches and peduncles is N. lutea tennis (Benth.) 

 Robinson. 



2. Neptunia pubescens Benth. Stems branched at the base, the branches 2-4 dm. 

 long, spreading or trailing, sparingly pubescent : leaves usually with 4-6 pinnae ; leaf- 



