Salix ×rubens Schrank
Small to medium-sized trees; bark rough and ± fissured. Branchlets spreading but not slender and pendulous. Shoots olive, brownish green or less commonly yellowish, usually snapping moderately easily, hairy when young. Buds brown, ± hairy. Petiole of lvs on reproductive shoots to c. 1 cm long. Lamina to c. 12 × 2.7 cm, lanceolate or narrowly elliptic-lanceolate, glaucous below, shining above, fairly soon glabrous, finely glandular-serrulate; apex acuminate. Stipules minute. Catkins ♂ or ♀, to c. 6 cm long, ♀ longer at fruiting, appearing with or after lvs; rachis villous. Bracts 2-4 mm long, elliptic-oblong, ovate-oblong, or oblong, green, strongly incurved, hairy to glabrate; apex usually obtuse to rounded, sometimes acute. Glands (1)-2, 3-7 mm long, elliptic-oblong to rectangular or square, sometimes wider than long. Stamens 2; filaments hairy towards base. ♀ fls with very short pedicels; ovary subsessile or with pedicel to c. 0.8 mm long, glabrous.
N.: mainly Manawatu; S.: eastern areas, especially Canterbury.
Europe 1983
Riverbeds.
FL Sep-Oct.
Hybrids between crack and white willows are often common where ♀ S. alba var. vitellina and ♂ S. fragilis grow together and are called S. × rubens. Plants of S. × rubens may be of either sex and it is likely that backcrossing occurs and may be common. In N.Z., as elsewhere, such hybrids are sometimes propagated and planted in waterside habitats. Some common ♂ plants, with deep yellow shoots, resemble the hybrid clone cv. 'Basfordiana', which is sometimes treated as a var. of S. fragilis or recently as a hybrid forma [Meikle, R. D., Watsonia 15(3): 273 (1985)]. Other wild plants of S. × rubens show more influence of S. alba and have young lvs silky, although these soon become glabrous. In many such plants the lf is narrower and with finer serrations than in S. fragilis, and the shoots are ± intermediate in brittleness between the 2 spp. However, brittleness varies with age and therefore is not always a reliable character. The presence of red or partly red rootlets in water and red willow sawfly galls on the lvs are also a feature of such hybrids as they are of S. fragilis.
