ROSACES 



565 



short claw. Fruit on stout slightly hairy or glabrous stems, oblong to oblong-obovoid, red, 

 covered with a thick glaucous bloom, f '-f ' long and f '-?' in diameter, with a thick skin 

 and thin flesh; stone oblong, compressed, pointed at the ends, slightly sulcate at apex, 

 unsymmetric, ridged on the full and rounded dorsal edge with a broad thin ridge, thin 

 nearly straight and only slightly grooved on the ventral edge, f-'-f ' long and about \' 

 wide. 



A tree 30 high, with a tall trunk usually about 12' but occasionally 18' in diameter, stout 

 spreading branches and stout or slender glabrous branchlets light orange green when they 

 first appear, becoming light gray or red-brown and lustrous at the end of their first season, 

 and dark dull red-brown the following year. Bark of the trunk and large branches thick, 

 pale gray, and broken into long platelike scales. 



Distribution. Dry Oak-woods near Jacksonville and Larissa, Cherokee County, Texas. 



7. Prunus mexicana S. Wats. Big Tree Plum. 

 Prunus arkansana Sarg. 



Leaves ovate to elliptic or obovate, abruptly long-pointed and acuminate at apex, 

 rounded or rarely cuneate and often glandular at base, and finely doubly serrate with 

 apiculate slender straight or slightly incurved teeth, at maturity thick, dark yellow-green, 



Fig. 519 

 



glabrous and lustrous on the upper surface, paler and sparingly covered on the lower surface 

 with long soft white hairs most abundant on the prominent midrib and primary veins and 

 on the numerous conspicuous reticulate veinlets, lf'-3|' long and l|'-2' wide; petioles 

 stout, pubescent or puberulous, glandular at apex with large dark glands, or eglandular, 

 ?'-' in length. Flowers appearing in March before the leaves, 1' in diameter, on slender 

 glabrous pedicels in 3 or 4-flowered sessile umbels; calyx-tube narrow-obconic, glabrous, 

 the lobes oblong or oblong-ovate, about as long as the tube, rounded and laciniate at 

 apex or entire, ciliate and glandular on the margins with small sessile glands, puberulous 

 on the outer surface, hoary-tomentose on the inner surface, reflexed after anthesis; petals 

 sometimes puberulous on the outer surface toward the base, ovate-orbicular to oblong- 

 ovate, rounded at the narrow apex, crenulate, abruptly or gradually narrowed below into a 

 short claw, about 3 times as long as the calyx-lobes; style longer than the stamens. Fruit 



