614 



TREES OF NORTH AMERICA 



Cercidium produces hard wood sometimes used as fuel. 



The generic name, from Keptddiov, refers to the fancied resemblance of the legume to 

 the weaver's instrument of that name. 



CONSPECTUS OF THE NORTH AMERICAN ARBORESCENT SPECIES. 



Legume compressed, with straight margins; leaflets green, slightly glandular. 



1. C. floridum (E). 



Legume somewhat turgid, the margins often slightly contracted between the seeds; leaf- 

 lets glaucous. 2. C. Torreyanum (G, H). 



1 . Cercidium floridum Benth. Green-barked Acacia. 



Leaves l'-l-|' long, with 2 or rarely 3 pinnae, a broad pubescent petiole and rachis, and 

 oval or somewhat obovate dull green puberulous minutely glandular leaflets about T y 

 in length, rounded or slightly emarginate at apex, and when they unfold covered on the 

 lower surface with scattered white hairs; petiolules short, stout, pubescent; appearing in 

 April and deciduous in October. Flowers opening with the leaves, and produced in suc- 



Fig. 562 



cessive crops during three or four months, f in diameter, on slender pedicels, in 4 or ;>- 

 flowered racemes H'-2' long, with small acute minute membranaceous caducous bracts. 

 Fruit compressed, oblong, straight or slightly falcate, acute, narrowly and acutely mar- 

 gined on the ventral suture, glabrous, 2 or 3-seeded, 2'-2|' long, \' broad, tardily de- 

 hiscent, 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 spreading 

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

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

 by occasional black lenticels, and armed with slender spines 1' or less in length. Bark 

 jJ^' 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 sap wood. 



Distribution. Shores of Matagorda Bay to Hidalgo and Valverde Counties, 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. 



