A hybrid between S. caprea and S. viminalis, the common osier, making a tall shrub or small tree to 20 ft or so high; young stems sparsely hairy, soon becoming more or less glabrous. Leaves broadly oblong-elliptic or broadly lanceolate, to about 7 in. long, soon glabrous above, the undersides greenish, coated with a thin woolly indumentum, the lateral and cross-veins both prominent. Catkins produced before the leaves, 11⁄2 to 2 in. long. This hybrid is fairly widely distributed in the British Isles, in waste ground, hedgerows, etc., either spontaneously or planted. The very vigorous male clone in commerce as S. × smithiana probably belongs here and agrees quite well with the male that has been cultivated since early in the 19th century under the name “S. rugosa”.
The hybrid between S. viminalis and S. cinerea also occurs. It differs in the more persistent down on the stems, the relatively narrower, lanceolate leaves, their undersides eventually almost glabrous and the cross-veins not prominent. This hybrid is less common than S. × sericans and male plants are rare.
S. × dasyclados Wimm. – This controversial willow does not occur in Britain, either wild or naturalised. It is represented in commerce by the male clone ‘Grandis’, originally distributed as “S. aquatica grandis”. It is a large shrub with stout stems, at first velvety, becoming glabrous or almost so. Leaves oblong-elliptic, acute, to 6 or 7 in. long, 1 in. or slightly more wide, sparsely silky beneath even when young; petioles to 1 in. long, much expanded at the base when subtending the closely set, downy catkin-buds. Stipules conspicuous, broad based, more or less abruptly narrowed at the tip, withering before falling. The handsome catkins, borne before the leaves, are about 2 in. long. ‘Grandis’ is not the same as the male clone in commerce as S. dasyclados simply. This, a hybrid of uncertain identity, is of extraordinary vigour, making seasonal stems 10 ft or so long when young and pruned. The catkins appear in late winter or early spring, sometimes in autumn.
S. dasyclados was described by Wimmer in 1849 from a specimen collected near Troppau in Silesia. Many authorities, among them the Russian salicologist Skvortsov, consider it to be a good species, of wide distribution from Silesia and Brandenburg eastwards as far as the Lena river, reproducing itself by seed and occurring in the same sort of habitat as S. viminalis, to which it is allied. According to others, it is a hybrid or perhaps an aggregate of hybrids, deriving from S. viminalis and one or more of the sallows. Certainly, S. dasyclados, as often understood, includes such hybrids and it may be that the actual type of S. dasyclados was a hybrid, in which case the species would need another name.
The following appear to be allied to S. dasyclados:
S. × calodendron Wimm. S. acuminata Sm., not Mill.; S. dasyclados of some authors, not Wimm.; S. × smithiana var. acuminata (Sm.) Anderss. – A shrub or small tree with stout, velvety young stems, the hairs persisting through the winter. Leaves oblong-elliptic or oblong-lanceolate, to about 51⁄4 in. long and 11⁄2 in. wide, tapered to an acute point, greyish and thinly downy beneath, with narrowly revolute margins. Stipules ovate-lanceolate, curved, retuse on the inner side at the base. Only female trees are known, with almost sessile, crowded, upward curved catkins 3 in. long. Of uncertain parentage, thought by Wimmer to be S. dasyclados × S. caprea. It occurs here and there in Britain, probably always planted, and is worthy of cultivation for its handsome catkins. Also known only as a female is S. × stipularis Sm., with more slender leaves, whiter and velvety beneath. The specific epithet refers to the very large stipules of the strong shoots, which are lanceolate, tapered, and about 1 in. long. It was apparently widely distributed early in the last century as S. viminalis, under which name it was sent to the botanical artist Sowerby by several growers when the English Botany was being prepared. Further details will be found in an article by R. D. Meikle published in Watsonia, Vol. 2 (1952), pp. 243-8.
These osier-sallow hybrids, despite their handsome catkins, are too robust and too coarse in foliage to be acceptable in any but the largest garden. But, because of their vigorous and tall growth, they are useful for quickly providing shelter for choicer things, or as a temporary screen.