60 BULLETIN 179, U. S. DEPARTMENT OF AGEICULTUEE. 



also grown, produced a very good crop of fruit in 1911. The fruit 

 of P. orthosepala is considered excellent in quality, and the Laire 

 bears abundantly and is considered an excellent plum. It is pos- 

 sible that all of these forms represent natural hybrids of P. americana 

 and the sand plum, both of which occur in northern Kansas; this 

 would account for the variation and possibly also for their rare 

 occurrence. Whatever their origin and whether they represent a 

 natural species or hybrids, they are unquestionably promising, at 

 least for the Plains region of Kansas and Oklahoma. 



Prunus Alleghaniensis Porter. 



(Northern sloe.) 



Prunus alleghaniensis Porter, 1877, in Bot. Gaz., v. 2, no. 6, p. 85. 



Leaves lanceolate to oval-lanceolate (PL V, fig. 2) or sometimes 

 broadest above the middle and slightly oblanceolate, mostly 6 to 9 

 cm. long, 2 to 3 cm. broad, acute or acuminate, the margin finely 

 and sharply serrate, very rarely doubly serrate, with or without 

 glands near the base of the blade, green and glabrous or sparingly 

 pubescent above and pale green below, usually pubescent, at least 

 when young, sometimes becoming glabrous with age, midvein 

 prominent; petiole 7 to 12 mm. long, pubescent, at least on the upper 

 side, rarely glandular at the apex; stipules linear with bright 

 reddish glands along the margin. Flowers appearing before the 

 leaves from the last of April to the middle of May, 10 to 12 mm. 

 broad, in nearly sessile umbels of 2 to 4; pedicels mostly 9 to 10 mm. 

 long, slender, sparingly hairy or glabrous; calyx narrowly obconic, 

 pubescent or sometimes glabrous, at least in cultivated specimens, 

 the tube about 3 mm. long and obscurely ribbed, the lobes narrowly 

 oblong-ovate, about 2 mm. long, erect, sparingly hairy or glabrous 

 within; petals about 5 mm. long, round-obovate and abruptly nar- 

 rowed to a short claw, the margin entire or sparingly erose toward 

 the apex, white, turning pinkish with age. Fruit subglobose or 

 somewhat oval or obovoid, about 10 mm. in its greatest diameter, 

 very dark purple and covered with bluish bloom, flesh yellow, 

 ripening in August; stone (PI. XII, fig's. 1 to 3) 11 to 12 mm. long, 

 8 mm. broad, shghtly obovoid and rather obtuse at the apex, turgid, 

 the ventral edge rather thick and grooved and the dorsal edge ob- 

 scurely grooved, the surface obscurely roughened. 



The species is a shrub 3 to 6 feet high, or more rarely a small tree 12 

 or more feet high, often forming thickets of considerable extent; 

 branches rarely spinescent, bark of the larger branches comparatively 

 smooth, very dark gray, that of the young twigs reddish brown and 

 somewhat lustrous, pubescent or frequently glabrous, lenticels oval 

 or round, sUghtly raised, yellowish brown; winter buds ovate, the 

 scales slightly hairy or glabrous. 



