SALIX 
21 
*S. alba x fragilis Wimmer in Denkschr. Schles. Gesellsch. 156 (1853); A. et G. Camus Classif Saul. 
238 (1904); v. Seemen in Ascherson und Graebner Syn. iv, 212 (1909) excl. syn. White; A. russelliana 1 Smith 
FI. Brit. 1045 (1804)!; 5 . viridis Fries FI. Suec. ed. 2, 283 (1828)!; Syme Eng. Bot. viii, 207 (1868); xS. 
viridis Wimmer Sal. Eur. 133 (18 66); White in Journ. Linn. Soc. xxvii, 371 (1890)! 
leones ; — Smith Eng. Bot. t. 1808, as S', russelliana (repeated in Syme Eng. Bot. viii, t. 1308, as S. viridis)-, 
Forbes Sal. Woburn, t. 28, as S', russelliana-, t. 127, as S', caerulea-, Host Hist. Sal. t. 24, t. 25, as S', palustris ; 
t. 28, t. 29, as S', excelsior-, FI. Dan. t. 2486, as S', viridis-, Reichenbach Icon. t. 610, fig. 1265, as S', russelliana-, 
A. et G. Camus op. cit., Atlas t. 22, fig. A — D, as x S', viridis. 
Camb. Brit. FI. ii. Plate 24. (a) Shoot with pistillate catkins. ( b ) Barren shoot. ( c ) Ripening capsules 
(enlarged). ( d ) Bract (enlarged). Huntingdonshire (E. W. H.). 
Exsiccata : — Fries, i, 61, as S', viridis ; Leefe, 55, as S', russelliana ; E. F. et W. R. Linton, 33. 
Trees, intermediate between S. alba and S. fragilis. Young branches less fragile at the base 
than S. fragilis. Leaves more or less covered with silky hairs when young, glabrous or glabrescent 
at maturity ; intermediate in size between S’, alba and S. fragilis. Nectaries very variable. Capsules 
with a longer stalk than in S. alba. 
S. russelliana Smith is a particular form or segregate of this hybrid, as his specimen conclusively shows. According 
to the account given by Smith (vide Eng. FI. iv, 186 (1828)) and by the Duke of Bedford (see the Introduction to 
Forbes Sal. Woburn. (1829)), this form was very valuable economically; and it would therefore be desirable to retain 
a form of the hybrid, under the name x Salix russelliana, if we could be certain of the precise form which constituted 
this, the Bedford or Leicestershire willow. 
There has, however, been much confusion among botanists with regard to the plant. In herbaria, we find willows 
named “ S. russelliana ,” many of which are simply forms of S. fragilis, whilst others are forms of A. alba x fragilis. Of 
course, a few of the latter may really be Smith’s plant ; but until the confusion has been cleared up, it is impossible 
to decide which of these are x S. russelliana and which are not. 
White (op. cit.) adopted a remarkable attitude with regard to S. fragilis. He maintained that S. fragilis Smith was 
S. alba x fragilis, and that S. russelliana Smith was S. fragilis Linn. We are unable to endorse this view. Not only 
is it inconceivable that Sir J. E. Smith, the greatest and most careful of Salicologists as well as one of the greatest 
of systematic botanists, did not know such a common species as S. fragilis, but his descriptions, figure, and specimen 
prove White’s view to be incorrect. Smith himself ( Eng . FI. iv, 187 (1828)) definitely rejected the view that his S. 
russelliana was “only the crack willow.” Smith’s specimen of his S. russelliana is, in our judgment, unmistakably a form 
of S. alba x fragilis. Syme (op. cit.) adopted this view in placing A. russelliana Smith as a synonym of the later name 
S. viridis Fries. The leaves of Smith’s figure of S. russelliana (Eng. Bot. t. 1808) are evidently from a coppiced shoot, 
and are older, larger, and less silvery than those of Smith’s specimen which is taken from a normal shoot. 
We conclude that the particular segregate or mutant x S. russelliana has been lost sight of ; but its alleged economic 
importance makes its rediscovery desirable. 
According to Smith (loc. cit.), it is a tree of quicker growth than S. fragilis. The bark is said to contain an 
exceptionally large quantity of tannin. Young bra?iches not angular at the point of insertion (Smith). Petioles with glands 
more often modified into leaflets than in S. fragilis. Laminae rather smaller, often more deeply serrated, more gradually 
acuminate, and more silky with hairs when young than in S. fragilis. Catkins lax-flowered, stalked. Staminate plants were, 
not known to Smith. 
Some continental works (e.g., Camus, op. cit., p. 239) describe a form x A. russelliana -, but, as this is described as 
having glabrous leaves, it differs from Smith’s type-specimen. 
The putative hybrids of 5 . alba and S. fragilis grow in similar situations as the supposed parents : they are 
fairly widespread and not uncommon in this country, being recorded from Somerset and Kent to Perthshire ; 
but they are less abundant and more local than the supposed parents. North of Ireland (Syme, op. cit.), but 
perhaps not indigenous there. 
Norway, Sweden, Denmark, Germany, Holland, Belgium, France, central Europe, Russia, the Balkan penin- 
sula ; the Caucasus. 
A", alba x pentandra (p. 1 6). 
[>S. alba X triandra Giirke Plant. Europ. ii, 5 (1897)?; A. et G. Camus Classif. Saul, ii, 99 (1905)?; excluding 
syn. White ; non Wimmer. 
leones: — A. et G. Camus op. cit., Atlas ii, t. 6 (39) fig. K (a leaf only), as x S. erythroclados , ? 
S. undulata Ehrhart is sometimes referred to S. alba x triandra. Wimmer (Sal. Eur. p. 144) adopted this view, 
after having previously held (Denkschr. p. 157 (1853)) that S. undulata Ehrhart should be referred to S. triandra x viminalis. 
MM. Camus (op. cit., i, 251) adopt Wimmer’s earlier view; but they also (op. cit., ii, 99) refer S. undulata Ehrhart 
herb, to S’, alba x triandra. The specimen of S’, undulata Ehrhart which we have seen in herb. Smith does not, however, 
agree with the description of S’, alba x triandra given by MM. Camus. 
For remarks on S. lanceolata Smith, see page 24. 
1 After Francis Russell (1765 — 1802), fifth Duke of Bedford, who first brought this willow into notice (cf. Smith Eng. 
FI. iv, 186 (1828)). 
