ROSACEAE. 



SORB ARIA A. Br. 



Determined by Alfred Rehder. 



Sorbaria arborea Schneider, III. Handh. Laubholzk. I. 490, fig. 297 

 (1905). 



Western Hupeh: Chang-lo Hsien, thickets, alt. 1500-2100 m., 

 July and October 1907 (No. 499''); Chang-yang Hsien, thickets, alt. 

 1500-1800 m., July 1907 (No. 2741); Fang Hsien, thickets, alt. 1500- 

 2100 m., July 1907 (No. 2742); Hsing-shan Hsien, woodlands, alt. 

 1500-1800 m., July 1907 (No. 2743); Patung Hsien, thickets, alt. 

 1500-2400 m., July 1907 (No. 2743^). Western Szech'uan: Mupin, 

 woodlands, alt. 1500-2400 m., November 1908 (No. 1235, in part); 

 Wa-shan, thickets, alt. 1600-2200 m., July 1908 (No. 2745). 



This variable species is most nearly related to S. Lindleyana Maximowicz from 

 which it differs in its longer stamens, two or three times as long as the petals, in 

 the shorter caljrx-tube and in the leaflets being cuneate at the base and covered 

 beneath with a fasciculate floccose tomentum or glabrous in one variety. 



Sorbaria arborea, var. subtomentosa Rehder, n. var. 



A typo recedit foliis subtus tomento fasciculato densiore usque ad 

 maturitatem persistente vestitis, argute minuteque biserrulatis, 

 venis magis congestis circa 2 mm. tantum distantibus, inflorescentia 

 dense floccosa, densiore, ramis adscendentibus, floribus majoribus, 

 petalis 3 mm. longis, carpellis pubescentibus vel glabris. 



Western Szech'uan: Wa-ssu country, Wen-chuan Hsien, wood- 

 lands, alt. 1800-3100 m., November 1908 (No. 1235, fruiting specimen, 

 type); Ta Hsing-ling, Ching-chi Hsien, thickets, alt. 1600-2200 m., 

 August 1908 (No. 2744, flowers) ; Pan-lan-shan, west of Kuan Hsien, 

 woodlands, alt. 2100-2400 m., September 1910 (No. 4474). 



Differs from the type in its denser persistent tomentum of the under side of 

 the leaves, their more closely set veins, 2 mm. apart, while in the type they are 3-4 

 mm. apart, and in the more densely tomentose inflorescence. In the type speci- 

 men the follicles are sparingly pubescent, while in the flowering specimen they are 

 quite glabrous; therefore these two specimens may possibly represent two dis- 

 tinct forms, but in fohage they are exactly alike. 



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