ROSACE:. SILVA OF NORTH AMERICA. 23 
PRUNUS TARDA. 
Sloe. 
CALYX-LOBES acuminate, entire, villose on the outer, tomentose on the inner surface. 
Fruit red, yellow, purple, black, or blue. Leaves oblong to obovate. 
Prunus tarda, Sargent, Bot. Gazette, xxxiii. 108 (1902). 
A tree, from twenty to twenty-five feet in height, with a tall trunk eighteen or twenty inches in 
diameter, and wide-spreading branches forming an open symmetrical head. The bark of the trunk is 
light brown tinged with red, from one half to five eighths of an inch in thickness, and divided by 
shallow interrupted fissures into flat ridges broken on the surface into small loose plate-like scales. 
The branchlets are slender and marked by small scattered dark lenticels, and when they first appear 
they are light green and coated with hoary tomentum, becoming glabrous, light red-brown and lustrous 
during their first summer, and darker at the end of their second year, when they lose their lustre. 
The winter-buds are narrow, acute, the color of the branchlets, and from one sixteenth to one eighth 
of an inch in length. The leaves are oblong or occasionally somewhat obovate, acute or acuminate 
and short-pointed at the apex, gradually narrowed and rounded or cuneate at the base, and finely 
serrate, with straight or incurved teeth tipped with dark minute persistent glands; as they unfold they 
are glabrous or rarely scabrous or puberulous above and cinereo-tomentose below, and at maturity 
they are thick and firm in texture, dark yellow-green and glabrous on the upper surface, pale and 
pubescent or puberulous on the lower surface, particularly along the prominent light yellow midribs and 
thin primary veins, from an inch and a half to three inches long and from three quarters of an inch 
to an inch and a quarter wide; they are borne on stout tomentose or ultimately pubescent petioles 
which vary from one third to one half of an inch in length and are furnished at the apex with two 
large round stalked dark glands or are often eglandular. The stipules are acicular, often bright red, 
and about a third of an inch long. The flowers, which are about three quarters of an inch in diameter, 
appear early in April with or before the leaves, and are borne in subsessile two or three-flowered 
umbels, on slender glabrous pedicels from five eighths to three quarters of an inch in length. The 
calyx-tube is narrowly obconic, glabrous toward the base, villose above, with acute entire lobes villose on 
the outer surface and coated on the inner surface with thick hoary tomentum. The petals are oblong- 
obovate and gradually contracted below into short claws. The filaments and pistils are glabrous. The 
fruits, which ripen late in October or early in November and sometimes do not entirely fall until 
nearly the beginning of December, are borne on stout rigid peduncles, and vary from short-oblong to 
subglobose and from one third to one half of an inch in length. The skin is tough and thick; and 
clear bright yellow on some trees, it is bright red on others, and on others either purple, dark blue, or 
black. The flesh is thick and very acid and adheres firmly to the stone, which is ovoid, more or less 
compressed, very rugose, obscurely ridged on the ventral suture and slightly grooved on the dorsal 
suture, acute and apiculate at the apex, and rounded at the base. 
Prunus tarda inhabits glades and open woods in the neighborhood of Marshall, Texas, where it 
was discovered in April, 1901, by W. M. Canby, B. F. Bush, and C. S. Sargent, and ranges to western 
Louisiana and southern Arkansas. Resembling in many of its characters Prunus umbellata, with 
which it has been sometimes confounded, Prunus tarda is well distinguished from that species by its 
remarkable bark, which is unlike that of any other American Plum-tree and which is hardly to be 
distinguished from that of Castanea pumila, growing with it, by the pubescence of the leaves, which 
