40 BULLETIN 179, U. S. DEPARTMENT OP AGRICULTURE. 



pressed, glandular serrate, the glands remaining as callous points, 

 glabrous and green above, pale green and pubescent with scattered 

 hairs below or rather densely pubescent when young, the pubes- 

 cence rarely or not at all tufted in the axils of the lateral veins; 

 petioles 10 to 12 mm, long, giandless or with one or two glands near 

 the apex, pubescent along the upper edge; stipules linear or lobed, 

 glandular. Flowers appearing in February or March, with or be- 

 fore the leaves, in umbels of 2 to 4 or rarely 5, about 9 or 10 mm. 

 broad; pedicels 6 to 8 mm. long, slender, glabrous; calyx campanu- 

 late, the tube glabrous, about 2 mm. long, the lobes as long as the tube 

 and ovate or oblong-ovate, usually pointed at the apex, glandular, 

 obscurely pubescent on the outside, pubescent on the inner surface 

 toward the base, and reflexed in age; petals 4 to 4.5 mm. or rarely 

 5 mm. long, 2.5 mm. broad, obovate-orbicular, or rarely oblong-obo- 

 vate, narrowed to a very short claw. Fruit ripening in June, sub- 

 globose, about 15 mm. in diameter, red with a light bloom; stone 

 oval to nearly globose (PI. X, figs. 23 and 24), 9 to 12 mm. long, 7 to 9 

 mm. broad, 6 to 7 mm. thick, rounded or shghtly pointed at the apex 

 and rounded or obliquely truncate at the base, irregTilarly grooved 

 along the vertical edge, the dorsal edge inconspicuously grooved or 

 sometimes smooth, surface obscurely rugose. 



The species is a shrub 3 to 8 feet high with slender stems, forming 

 open thickets. The bark of the stems is gray, that of the young 

 twigs grayish or rarely somewhat reddish or pale chestnut in color, 

 obscurely marked with oval lenticels; winter buds small. 



Prunus rivularis occurs (fig. 2) in bottom lands along streams in 

 Texas from the Rio Blanco, in Hays County, to San Antonio. It is 

 apparently not very abundant. 



The species was originally described from a specimen collected by 

 Lindheimer, but neither the date nor locality are cited by Scheele. 

 Among the seven specimens in the herbarium of the Missouri Botan- 

 ical Garden collected by Lindheimer, one (No. 274, 1846) has a label with 

 the same data that are given by Scheele and is apparently a duplicate 

 of the type. On the same sheet is a package of stones labeled ''New 

 Braimfels, Texas, 1846, Lindheimer," and there can be little doubt 

 that this is the type locality. Prunus texana was described from ma- 

 terial collected by Roemer at New Braunfels, and a flowering speci- 

 men of his in the herbarium of the Missouri Botanical Garden, ''Pru- 

 nus texana Scheele," bears the legend ''Scheele misit" and is evi- 

 dently part of the type material. It does not differ from P. rivularis. 

 The Indians, according to Lindheimer, gathered these plums and 

 cooked them with honey, but the fruit is small, poor in quality, and 

 the species apparently has little value in horticulture. 



