44 BULLETIN 119, V. S. DEPAETMENT OF AGRICULTUEE. 



Peunus Angustipolia Hybrids. 



The early ripening of the fruit of Prunus angustifolia has caused 

 it to be used in hybridizing with P. trijlora (PI. XIII, fig. 13, Six 

 Weeks) with which it crosses very readily, and it is supposed also to 

 be one of the species used in producing the variety Chicrigland. 

 This is said to be a combination of P. angustifolia, P. reverchonii, and 

 P. texana (P. glandulosa (Hook.) Torr. and Gray). 



Prunus Angustifolia Watsoni (Sargent) Waugh. 



(Sand plum.) 



Prunus watsoni Sarg., 1894, in Gard. and Forest, v. 7, p. 134, f. 25. 



Prunus angustifolia watsoniW augh, 1899, m Vt. Agr. Exp. Sta., 12th Ann. Rpt., 239. 



Leaves oval or oblong-oval, 3 to 4.5 cm. long, 12 to 18 mm. broad, 

 gradually narrowed toward the base, usually acute at the apex, some- 

 times abruptly so, lustrous above, pale and glabrous below or some- 

 times a few scattered hairs along the midrib toward the base, the 

 margin finely crenate and glandular; petioles slender, 6 to 18 mm. 

 long, glabrous, or sometimes pubescent along the upper edge. Flowers 

 appearing in Kansas from the last of March to about April 20, some- 

 times with red anthers, otherwise not differing from the species. Fruit 

 very similar to the species, but ripening from the first of August 

 to the first of October, or in the Panhandle region early in July; 

 stone oval or rarely obovoid, about 13 or 14 mm. long, 9 mm. broad, 

 7 mm. thick, truncate or obMque at the base, rounded or pointed 

 at the apex, variously grooved on either side of the ventral edge or 

 the grooves very obscure but without a winghke margin, grooved 

 along the dorsal edge, prolonged at the base when obovoid. 



Prunus angustifolia watsoni is usually a shrub 3 to 6 feet high 

 with rather stiff branches, these often furnished with spinescent 

 branchlets. 



The subspecies was originally described from garden specimens 

 grown from seed sent from EUis, Kans., by Dr. Louis Watson. It 

 ranges from northeastern Kansas southwestward through Oklahoma 

 and the Panhandle region of Texas to the vicinity of Nara Visa, 

 Quay County, in northeastern New Mexico. Its eastern boundary 

 is not well defined, but no specimens have been observed east of a 

 line drawn from the northeastern part of Kansas southwestward 

 to the junction of the North Fork of Red River with the main 

 stream, yet it doubtless occurs somewhat farther east. It does 

 not appear to have been collected much west of EUis and Seward 

 Counties, in Kansas. It has several times been reported from 

 southeastern Nebraska, but no specimens are to be found in the 

 larger herbaria from that region, and it probably occurs in Nebraska 

 only under cultivation. 



