576 MIMOSACEAE 



1. Pithecolobium Guadalup6nse (Desv. ) Chapm. An unarmed shrub 1-2 m. tall. 

 Leaflets 4, the blades obliquely obovate or oblong-obovate, 2-4 cm. long, leathery, mucro- 

 nate, undulate, delicately nerved, lustrous above : petioles shorter than the petiolules : 

 heads yellow: peduncles solitary on the axils, 4-8 cm. long, surpassing the subtending 

 bracts : calyx campanulate, pubescent, the triangular lobes shorter than the tube : corolla 

 pubescent : stamens 3-4 times longer than the corolla, crisped : ovary pubescent : pods 

 5-10 cm. long, contorted. 



In sand, Florida keys. Also in the West Indies. 



2. Pithecolobium Unguis-Cati (L. ) Benth. An armed or unarmed straggling shrub 

 or small tree, sometimes 8 m. tall. Leaflets 4, the blades thinnish, obliquely obovate or 

 oval, rounded or mucronate at the apex, delicately reticulated ; petioles slender, mostly 

 much longer than the petiolules: heads in terminal axillary panicles: calyx turbinate- 

 campanulate, glabrous, the triangular lobes much shorter than the tube : corolla glabrous 

 or nearly so : stamens about twice as long as the corolla : pods 8-12 cm. long, contorted. 



In sand, southern peninsular Florida and the Keys, also in the West Indies and tropical America. 



2. SIDEROCARPOS Small. 



Trees, with spreading branches and zigzag twigs. Leaves alternate, but often clustered : 

 blades 2-pinnate, with 4-6 pinnae : leaflets relatively few. Flowers mostly perfect, in 

 cylindric spikes. Calyx campanulate, 5-lobed, very different from the corolla. Corolla 

 5-lobed, the lobes longer than the tube. Stamens numerous : filaments united below. 

 Ovary sessile : style filiform. Ovules numerous. Pods stout and turgid, very tardily de- 

 hiscent, the valves woody, enclosing a soft tissue which separates the seeds from each other. 

 Seeds transverse, on straight funicles. TEXAN EBONY. 



1. Siderocarpos flexicaulis (Benth. ) Small. An evergreen shrub or tree, reaching 

 a height of 10 m., armed with short spines. Leaves with 4-6 pinnae; leaflets 6-8, the 

 blades oblong, oval or obovate, 5-10 mm. long, usually obtuse, delicately reticulated 

 beneath : peduncles I -1.5 cm. long : spikes cylindric, 2-4 cm. long, often clustered in the 

 axils: calyx campanulate, about 0.5 mm. high : corolla 4-5 times longer than the calyx, 

 the lobes longer than the tube : pods narrowly oblong, 1-1.5 dm. long, thick and turgid, 

 slightly curved, sessile. [Pithecolobium flexicaule (Benth.) Coulter.] 



On bluffs, Texas and Mexico. Summer. 



3. HAVARDIA Small. 



Small evergreen trees, sometimes shrubby, armed with stipular spines. Leaves alter- 

 nate : blades 2-pinnate, with 6-10 pinnae : leaflets numerous (20-40 in each pinna), rela- 

 tively small. Flowers perfect, in head-like spikes. Calyx quite short, 5-lobed, very dif- 

 ferent from the corolla in shape and texture. Corolla 5-lobed, the lobes shorter than the 

 tube. Stamens numerous : filaments united below. Ovary stipitate : style filiform. 

 Ovules several. Pods flat, readily dehiscent, with membranous or thin-leathery valves. 

 Seeds few. HUAJILLO. 



1. HavardU brevifolia (Benth. 1 Small. An evergreen shrub or small tree, some- 

 times 10 m. tall, armed with short spines. Leaves with 6-10 pinnae; leaflets 20-40, the 

 blades oblong or narrowly oblong, 3-7 mm. long, obtuse or acutish, reticulated beneath : 

 panicles 5-10 cm. long : peduncles- 1-1.5 cm. long : heads subglobose, about 2 cm. in diam- 

 eter : corolla 6-8 times longer than the calyx, the ovate lobes shorter than the tube : sta- 

 mens between twice and thrice longer than the corolla: pods linear-oblong, flat, 7-10 

 cm. long, acuminate at the apex, stipitate. [Pithecolobium brevifolium Benth.] 



In valleys, southern Texas and northern Mexico. 



4. ALBIZZIA Durazz. 



Unarmed shrubs or trees, with wide spreading branches. Leaves alternate, blades 2- 

 pinnate : leaflets small, numerous, their glands, as well as the petiolar glands, more or less 

 conspicuous. Flowers perfect, or polygamous, in peduncled, sometimes panicled, capitate 

 spikes. Calyx tubular to campanulate, 5-lobed. Corolla funnelform, the lobes often 

 ^shorter than the tube. Stamens numerous, exserted : filaments united at the base of the 

 corolla-tube and sometimes adnate to it. Ovary often short-stalked. Pods linear, flattish, 

 2-valved, the valves not separating from the margins, or indehiscent 



