, LEGUMINOS^: 563 



about ^j' 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, f in 

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

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

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

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

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

 seeds ' 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, 



and branclilets 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 Mad re. 



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



Leaves few and scattered, 1' 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, ^V~V l n > unfolding in 

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

 diameter, on slender pedicels, in 4 or 5-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, \' 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 



