558 



TREES OF NORTH AMERICA 



filaments villose near the base and green anthers; pistillate flowers unknown. Fruit 

 4'-5' long, V wide, straight, much compressed, rounded and short-pointed at the 



apex full and rounded at the broad base, thin-walled, dark chestnut-brown, puberu- 

 lous, slightly thickened on the margins, many-seeded, without pulp; seeds oval, 

 compressed, dark chestnut-brown, very lustrous, ^' long. 



A tree, 100-120 high, with a trunk rarely exceeding 2^ in diameter, ascending 

 and spreading branches forming a narrow head, and comparatively slender more or 

 less zigzag branchlets roughened by numerous small round lenticels, light orange- 

 brown when they first appear, gray or orange-brown during their first year, ashy 

 gray the following season, and unarmed. Bark thin and smooth. 



Distribution. Only in a single grove on the bottom-lands of the Brazos River, 

 near the town of Brazoria, Texas. 



3. Gleditsia aquatica. Marsh. Water Locust. 



Leaves 5'-8' long, 12-18-foliolate, or doubly pinnate, with 3 or 4 pairs of pinnae; 

 leaflets ovate-oblong, usually rounded or rarely emarginate at the apex, unequally 

 wedge-shaped at the base, slightly and remotely crenate or often entire below the 

 middle, glabrous with the exception of a few hairs on the short stout petiolules, dull 

 yellow-green and lustrous on the upper surface, dark green on the lower surface, 

 about 1' long and ^'-|' wide. Flowers appearing in May and June after the leaves 

 are fully grown on short stout purple puberulous pedicels, in slender racemes 3'^' 

 long; calyx-tube covered with orange-brown pubescence, the lobes narrow, acute, 

 slightly pilose on the two surfaces, as long as but narrower than the green erect petals 

 rounded at the apex; filaments hairy toward the base; anthers large, green; ovary 

 long-stipitate, glabrous. Fruit fully grown in August, pendent in graceful racemes, 

 obliquely ovate, long-stalked, crowned with a short stout tip, thin, V-2' long, V broad, 

 without pulp, its valves thin, tough, papery, bright chestnut-brown, lustrous and some- 

 what thickened on the margins; seeds 1 or 2, flat, nearly orbicular, orange-brown, 

 i' in diameter. 



A tree, 50-60 high, with a short trunk 2-2^ in diameter, usually dividing a 

 few feet from the ground into stout spreading often contorted branches forming a 

 wide irregular flat-topped head, and glabrous orange-brown branchlets becoming in 

 their second year gray or reddish brown, marked by occasional large pale lenticels, 



