ROSACEAE. 



97 



SORBABIA. 



(Family Rosaceae). 



Low and little-branched shrubs: 

 deciduous. Twigs terete, some- 

 what zig-zag, stout for the size of 

 the plant, glabrous: pith rela- 

 tively large, rounded, brown, con- 

 tinuous. Buds ovoid, moderate 

 and sessile, with about 4 exposed 

 scales, or quickly developing so as 

 to become large, open, stalked and 

 collaterally multiple, the end-bud 

 lacking. Leaf-scars alternate, 

 rather large, half-round to round 

 or elliptical, more or less angled 

 or truncate, little raised: bundle- 

 traces 3, large: stipule-scars lack- 

 ing. 



Sorbaria has been considered a 

 part of the genus Spiraea by many 

 botanists, and on the other hand 

 those who segregate it sometimes 

 use the generic name Basilima for 

 its species. The following winter-character references may 

 be given: 8. alpina. Schneider, f. 133. S. sorbifolia. Bose- 

 mann, 76; Schneider, f. 133. The reason why no terminal 

 bud is found in Sorbaria, and the structure of its buds, are 

 considered in an extensive article on buds published by Ohlert 

 in the journal Linnaea for 1837. 



1. Twigs and buds red-brown. (1). S. Lindleyana. 

 Twigs and buds gray-brown. 2. 



Twigs purple: capsules glabrous. S. Aitchisoni. 



2. Capsules glabrous. (2). S. sorbifolia. 

 Capsules loosely hairy. S. stellipila. 



