LEGUMINOS^ 



563 



about ylj' in length, rounded or slightly emarginate at the apex, and when they un- 

 fold covered on the lower surface with scattered white hairs; their petiolules short, 

 stout, pubescent, appearing in April and deciduous in October. Flowers opening 

 with the leaves, and produced in successive crops during three or four months, in 

 diameter, on slender pedicels, in 4 or 5-flowered racemes l^'-2' long, with small 

 acute minute membranaceous caducous bracts. Fruit compressed, oblong, straiglit 

 or slightly falcate, acute, narrow and acutely margined on the ventral suture, gla- 

 brous, 2 or 3-seeded, 2'-2y long, i' broad, tardily dehiscent, the valves papery, 

 yellow tinged with brown on the outer surface, and bright orange color within; 

 seeds i' long. 



A tree, 18-20 high, with a short crooked trunk 8'-10' in diameter, stout spread- 

 ing branches covered with thin smooth bright green bark, forming a low wide head, 



W^S 



and branchlets light or dark olive-green, slightly puberulous at first, soon glabrous, 

 marked by occasional black lenticels, and armed with slender spines V or less long. 

 Bark -^-^' thick, light brown tinged with red, with numerous short horizontal light 

 gray ridge-like excrescences. Wood light, soft, close-grained, pale yellow tinged 

 with green, with thick lighter colored sapwood. 



Distribution. Shores of Matagorda Bay to Hidalgo County, Texas, and in 

 northern Mexico; not common in Texas; very abundant and a conspicuous feature 

 of vegetation in Mexico from the mouth of the Rio Grande to the foothills of the 

 Sierra Madre. 



2. Cercidium Torreyanum, Sarg. Green-barked Acacia. Palo Verde. 



Leaves few and scattered, V long, at first hoary-tomentose, puberulous at matur- 

 ity, with slender petioles and 2 pinnae, each with 2 or 3 pairs of oblong obtuse glau- 

 cous leaflets narrowed toward the somewhat oblique base, iV~6' ^^ng, unfolding in 

 March and April and falling almost immediately when fully grown. Flowers f in 

 diameter, on slender pedicels, in 4 or o-flowered racemes, about V long, with small 

 acute membranaceous caducous bracts. Fruit ripening and falling in July, 3'-4' 

 long, 2-8-seeded, slightly turgid, often somewhat contracted between the seeds, 

 frequently grooved on the ventral suture; seeds turgid, i' long. 



A low intricately branched tree, leafless for most of the year, 25-30 high, with 

 a short often inclining trunk 18'-20' in diameter, stout branches covered with yellow 



