10 JOIRNAL OF THE ARNOLD ARRORETUM [vol. ii 



forms are, liowevcr, not clearly separaled. The variability seems to be the 

 ^ame in diflerent localities, and Ball riglilly states (1915) tliat it is " an im- 

 mensely variable sjjccies esi)ecially as to foliage." J. K. Henry, having 

 in mind in 1915 only the variations of typical S. Scouleriana in southern 

 Urilish Columbia, likewise asserts that the species is "very variable, i)resent- 

 ing many ill defined forms." Api)arently he made careful observations 

 of these forms in the field, and besides the type he distinguished a var. 



fl 



typ 



fl 



leaved 



fcjinis (folia 5-10 cm. longa). Of the last he says: "' These are two recof^uiz- 

 able forms of this var. (a) leaves prevailingly obovate and o!)tuse, 4-6 cm. 

 hroad, common on V.I. (b) Leaves prevailingly oblanceolatc and acute; 

 but the U\o inlergrade." In 1899 Ball as already stated was inclined to sepa- 

 rate the coast form from that of the mountains, the last being identical with 

 the typical S. flavescens; m 1909, however, he only says: "Forms w^ith 

 j-hort stout amenls may be referred to var. cras.sijuUs Anders," but he does 

 not n.ention other forms. 



It is cxdcmcly difhcult to analyze correctly the different forms of such a 

 varial>!e species. It woidd be an easy task to describe as many varie- 

 ties as have for instance been made of the European S, nigricans, but noth- 

 ing couhl he gained by doing this. Wc need many more careful observa- 

 tions in tlie field, and much more material collected from the same individual 

 at different seas(rns of the year from every part of its habitat. We arc far 

 frrm having a good idea of the variability of the individual i)lant and of its 

 adnijtabili(y to certain ecological and climatic conditions. The dilfercnces 

 in the flowers (size of the aments, glabrousness or pubescence of the fila- 

 ments, si^c and color of the anthers, length of the stigmas and of the style, 

 length of the pedicel, etc.) do not seem to afford very reliable characters on 

 which to base varieties or even forms. The pubescence of the twigs and 

 leaves Avhidi often looks so distinct, at least in the herbarimu, is changeable 

 in the same i)lant according to the season or locality; and I am far from being 

 able to decide the taxonomic value of these variations. 



It is not less diflicult to apply certain names to certain forms. As may be 

 seen by what has been said and by the synonymy given above, a good many 

 ccmbinalions have already been made. Several of them api^ly to identical 

 forms. The oldest varietal name var, temiijidis Anders, is synonymous with 

 tyi>ical S. Scovlericwa, while var. crassijidis Anders, can only be used for 

 (he form whi<'h is identical with the typical S. capreoides which moreover is 

 nothing but 5. hrachy.stachy,s Benth. 



fi 



fl 



Nuttalbbut probably typical S. Scouleriana or at least aform of it. Nuttall\s 

 flav€ic€7us may })e a form of the mountains which, at present, I cannot clearly 

 distinguish from the northern coastal form. NuttalPs S. slagnalLs from the 

 Colun.bia in Oregon seems to agree with typical S. Scouleriana, Ibniry's 



small-leaved form. Here the leaves are indeed, as Xuttall says, ''scattered 



