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REVISION OF THE BRITISH WILLOWS. 381 



of Salix cinerea, Boswell-Syme and, following him, J. D. Hooker 

 term them and cinerea genuina slight varieties, which so run into 

 each other that it is often impossible to refer a specimen to one more 

 than to another, the distinctions being that oleifolia has narrower 

 leaves with (as in cinerea genuina) reddish-brown hairs beneath, and 

 aquatica obovate thinner leaves with usually white hairs beneath. 

 Andersson considers them as synonyms of 8. cinerea, aquatica 

 being most probably his var. latifolia. Wimmer makes 8. oleifolia 

 a synonym, but, on account of Sal. Wob. 1. 127 and Doll's opinion 

 of Eng. Bot. t. 1437, refers aquatica to the hybrid S. Caprea- 

 cinerea, Wimm. Walker-Arnott cannot distinguish them as well- 

 marked varieties, and points out the fallacy of characters derived 

 from the stipules, in whose structure Smith placed reliance. W. J. 

 Hooker retains them as species, but states Borrer's opinion that 

 their characters are unsatisfactory. These quotations will be 

 sufficient to show that the general opinion is that S. aquatica 

 and S. oleifolia are scarcely distinct, as varieties even, from S. 

 cinerea, an exception being Wimmer's idea (derived from figures 

 only) that S. aquatica is a hybrid between S. cinerea and S. Caprea. 



One or two points in Smith's descriptions are not alluded to by 

 modern botanists. S. cinerea he describes as a tree 20-30 feet 

 high if left to its natural growth. S. oleifolia is also a tree ; but 

 S. aquatica is generally bushy, rarely forming a tree. The catkins 

 of S. oleifolia are as large as those of S. Caprea, those of S. aquatica 

 oeing much smaller and more like those of S. cinerea. He also says 

 that S. aquatica is " most related " to aurita, and places the species 

 in this order— 8. cinerea, S. aurita, 8. aquatica, S. oleifolia. 



u Pith's herbarium specimens of both S. aquatica and S. olei- 

 folia, from " Mr. Crowe's garden," are preserved. These are in- 

 s ructive in several ways, and show some discrepancies with the 

 descriptions. The specimen of S. aquatica much resembles 



-aurita in twigs and catkins ; the leaves are thin, not very hairy, 

 * utile rugose above, margins slightly undulate-crenate, and under- 

 side with reddish-brown hairs. It looks like a hybrid of 8. aurita 

 I either & cinerea or S. Caprea, the pubescence of the young 

 eaves suggesting the latter. The 8. oleifolia specimen has rather 

 fonder aurita-like twigs which are not very pubescent; the 



a ! es resen ible those of cinerea, have slightly revolute and sub- 



Ttv margins ' and the underside has reddish-brown hairs ; the 

 ins (cJ) are i arger t jj Cn thoge of t j ie ugual aur ita % but small 



* cinerea, and their scales are suggestive of aurita. With the 



*™. JOUBK.-^BOTA* Y, VOL. XXVII. 2 D 







