196 WILSON EXPEDITION TO CHINA 



the upper half of the leaf. It is much less hairy than the type and quickly be- 

 comes glabrous. 



This Amelanchier is one of the commonest and most beautiful of the small trees 

 in the thickets and thin woods of western Hupeh. 



PRUNUS L. 



Determined by E. Koehne. 



Subgen. PADUS. 



For the species of this subgenus collected by Mr. Wilson and a 

 key to all the Chinese species, see pp. 59-75. It remains only to add 

 here the determinations of the specimens of Padus collected by 

 Mr. Wilson during his journey of 1910.^ 



Prunus pubigera Koehne, var. Potanini Koehne in Sargent, PI. 

 Wilson. 68 (1911). 



Western Szech'uan: southeast of Tachien-lu, woods, alt. 3000- 

 3300 m., October 1910 (No. 4133, tree 23-27 m. high, 2 m. circum- 

 ference, pendulous racemes). 



As I have not seen foliiferous shoots I have some doubt whether No. 4133 

 really belongs to this variety. 



Prunus pubigera, var. obovata Koehne, 1. c. (1911). 



Western Szech'uan: Pan-lan-shan, west of Kuan Hsien, wood- 

 lands, alt. 3000-3300 m., August 1910 (No. 4036, tree 14-16 m. 

 high, 1.6-2 m. circumference); west and near Wen-ch'uan Hsien, 

 woods, alt. 2300-2800 m., September 1910 (No. 4185, tree 7-12 m. 

 high, 1-1.3 m. circumference). 



Prunus sericea Koehne, 1. c. 63 (1911). 



Western Szech'uan: Mupin, woods, alt. 1600-2000 m., October, 

 1910 (No. 4219, tree 14 m. high, 1.6 m. circumference). 



1 Here may also be added the description of a new form collected by Mr. 

 Purdom. 



Prunus Padus Linnaeus, var. pubescens Regel, f . Purdomii Koehne, n. f. 



Ramuli novelli tomento moUi cinerascentes, vetustiores plus minus glabrati. 

 Petioli dense pubescentes cinerascentes, lamina subtus cinereo-tomentosa. Racemi 

 pedunculus minutim puberulo-velutinus, axis ipse glaberrimus. 



Northern Chili: Weichang, May 26, 1909, Wm. Purdom (No. 15). 



This form is remarkable for the tomentose lower surface of all the leaves, while 

 the axis of the raceme is quite glabrous. 



