578 MIMOSACEAE 



oblong, 2.5-5 mm. long, mostly blunt: spikes globose, about 1.5 cm. in diameter, the 

 peduncle pubescent like the subtending rachis : pods broadly linear, 3-6 cm. long, 6-8 mm. 

 wide, delicately veined, abruptly acuminate. 



In dry soil, Texas to Arizona. Spring and summer. 



4. Acacia constricta Benth. A shrub, armed with spreading straight or slightly 

 curved spines, the foliage often sticky. Leaves 3-6 cm. long, with 4-14 pinnae ; leaflets 

 12-20, the blades oblong, 1.5-2 mm. long, obtuse, nerveless : spikes globose, 8-10 mm. 

 thick, on pubescent peduncles 1-2 cm. long : pods elongated, linear, constricted between 

 the seeds, glabrous, 5-13 cm. long, each narrowed into a stipe. 



In dry soil, southern Texas to New Mexico, and adjacent Mexico. Spring. 



5. Acacia Roemeriana Schlecht. A stout shrub, with spreading branches, armed 

 with stout prickle-like spines. Leaves 3-10 cm. long, with 4-6 pinnae ; leaflets 8-16, the 

 blades oblong, oval or cuneate, 8-10 mm. long, oblique, apiculate or retuse at the apex, 

 prominently nerved : spikes globose, 8-10 mm. thick, on glabrous peduncles 1-2 cm. long : 

 pods flat, oblong or linear-oblong, 5-15 cm. long, slightly curved, each narrowed into a 

 stipe, the valves prominently nerved near the edges. 



In dry soil, southern Texas, New Mexico and Mexico. Spring. 



6. Acacia Wrightii Benth. A shrub or small tree, with streaked branchlets armed 

 with short prickles. Leaves numerous, 2-3.5 cm. long, usually with 4-6 pinnae; leaflets 

 6-12, the blades oblong to obovate, 5-7 mm. long, often minutely pointed, prominently 

 nerved beneath : racemes cylindric, 2-3 cm. long, not very dense : flowers slender-pedi- 

 celled : pods 8-11 cm. long, 2-2.5 cm. broad, curved, often irregularly undulate along the 

 margins. 



In dry soil, Texas, New Mexico and adjacent Mexico. Spring and summer. TEXAS CATSCLAW. 



7. Acacia Gr6ggii A. Gray. A shrub or small tree, commonly armed with short 

 curved prickle-like spines. Leaves 2.5-5 cm. long, with 2-6 pinnae; leaflets 8-14, the 

 blades firm, oblique, oblong to cuneate, 4-6 mm. long, apiculate, obtuse or truncate at the 

 apex, prominently nerved : spikes long-peduncled, 2-4 cm. long : pods flat, linear-oblong, 

 8-12 cm. long, sometimes glaucous, irregularly constricted between the seeds. 



In dry or rocky soil, Texas and Mexico. Spring and summer. DEVIL'S CLAWS. PARADISE FLOWER. 

 CATSCLAW. 



8 Acacia amentacea DC. A glabrous shrub, with zigzag branches, armed with 

 straight or slightly curved pale spines 1-2 cm. long. Leaves 1-2 cm. long, with 2 pinnae ; 

 leaflets 4-8, the blades firm, obliquely oblong or obovate, 4-6 mm. long, truncate or retuse 

 at the apex, prominently nerved : racemes oblong, 1-2 cm. long : pods linear, flat, 6-10 

 cm. long, curved, constricted between the seeds, usually acuminate at the apex, each attenu- 

 ate at the base into a stipe. 



On hillsides, from the Guadalupe River to the Pecos, south to Mexico. Spring. 



7. VACHELLIA Wight & Arn. 



Shrubs or small trees, with spreading branches and straight spines. Leaves alternate : 

 blades 2-pinnate, with 8-16 pinnae : leaflets numerous (20-50 in each pinna), relatively 

 small. Flowers polygamous, in globular spikes. Calyx simulating the corolla but only 

 about as long, shallowly 5-lobed. Corolla tubular-funnelform, shallowly 5-6-lobed, the 

 lobes as broad as high. Stamens very numerous : filaments distinct. Ovary sessile : style 

 filiform. Pod stout, turgid, nearly terete or usually broader than high, scarcely dehiscent, 

 filled with a pulp which separates the two rows of seeds and the individual seeds from each 

 other. HUISACHE. CASSIE. 



1. Vachellia Farnesiana (L. ) Wight & Arn. A shrub or small tree, with spread- 

 ing branches and straight spines 5-15 mm. long. Leaves 1-2.5 cm. long, with 8-16 

 pinnae ; leaflets 20-50, the blades linear-oblong, 2-4 mm. long, rather obtuse : spikes 

 globose, 8-12 mm. in diameter, on pubescent peduncles 1-2 cm. long : pods cylindric, 3- 

 7.5 cm. long, straight or slightly curved, often slightly constricted between the seeds. 

 [ Acacia Farnesiana (L. ) Willd.] 



On plains and prairies, southern Texas and Mexico, also naturalized in Florida. Spring, fruit ripe 

 in summer. YELLOW OPOPANAX. 



8. LEUCAENA Benth. 



Evergreen shrubs or trees, usually unarmed. Leaves alternate : blades pinnate ; 

 petioles often furnished with a gland, the leaflets subtended by setaceous stipels : leaflets 



