SAPOTACE.E 



815 



with snow white pubescence when they unfold, and at maturity coriaceous, dark yellow- 

 (?reen, lustrous and glabrous on the upper surface, paler on the lower surface, l|'-3' long 

 and ^'-l ' wide, with slightly revolute margins, a slender yellow midrib glabrous or slightly 

 pubescent below toward the base and conspicuous reticulate veinlets, deciduous; petioles 

 slender pubescent early in the season, becoming glabrous. Flowers opening from the mid- 

 dle of June to the middle of July, on villose pedicels, becoming sometimes nearly glabrous 

 in the autumn, |-'-j' in length; calyx pale green, villose-pubescent, its lobes ovate, ciliate on 

 the margins, shorter than the lobes of the corolla, their appendages lanceolate; staminodia 

 rounded at apex, longer than the corolla-lobes. Fruit ripening in September, subglobose 

 to oblong-obovoid, \'-\' long and '-$' in diameter; seed oblong, rounded at the ends, 

 about f ' long. 



A tree, in favorable positions 20-25 high, with spinose branches forming an irregular 

 open head, and slender often zigzag red-brown lustrous branchlets, the lateral branchlets 



Fig. 725 



often ending in stout spines; more often an irregularly branched shrub 10-15 high, spread- 

 ing on the banks of streams into great thickets. Bark of the trunk thick, pale and dark 

 gray, rough and scaly, exfoliating in large scales. 



Distribution. Texas, dry limestone cliffs and canon bottoms and by streams dry during 

 a large part of the year, valley of the upper Guadalupe River (Comal, Kendall and Kerr 

 Counties) to the valley of the Rio Grande (Uvalde County), and northward to the valley of 

 the upper Brazos River (Palo Pinto County); in Cohahuila (near Saltillo). 



4. Bumelia lycioides Gaertn. f. Ironwood. Buckthorn. 



Leaves elliptic to oblanceolate, acute, acuminate, or rarely rounded at apex, gradually 

 narrowed at base, covered when they unfold especially below with silky villose pubescence, 

 soon glabrous, and at maturity bright green and glabrous on the upper surface, light green 

 and sometimes coated on the lower surface with pale pubescence, thin and rather firm, 

 finely reticulate-venulose, 3'-6' long and ^'-2' wide, with a pale thin conspicuous midrib 

 sometimes slightly pubescent below near the base, deciduous in the autumn; petioles slen- 

 der, slightly grooved, mostly pubescent early in the season, usually becoming glabrous, \'- 

 1' in length. Flowers appearing at midsummer on slender glabrous pedicels \' long, in 

 crowded many-flowered fascicles; calyx glabrous, ovoid-campanulate, with rounded lobes 

 rather shorter than the corolla; staminodia broad-ovate, denticulate, nearly as long as the 

 narrow appendages; ovary ovoid, slightly hairy toward the base only, gradually contracted 

 into a short thick style. Fruit ripening and falling in the autumn, ovoid or obovoid, about 



