Salix alba L.
Tree to c. 25 m high, but usually much < 15 m; bark dark greyish, fissured. Branchlets and shoots spreading to erect, usually yellow or orange-yellow, sometimes olive, greenish brown or red, tough and flexible, not snapping, soon glabrous. Buds glabrous and brown, or whitish hairy. Petiole of lvs on reproductive branches usually < 1 cm long. Lamina 4-13 × 1-2-(2.7) cm, lanceolate, ± shining and usually soon becoming glabrous on upper surface, glaucous and usually eventually glabrous on lower surface, sometimes persistently silky hairy on both surfaces, glandular-serrulate, sparsely to densely ciliate; apex acute or short-acuminate. Stipules minute. Catkins ♂ or ♀, appearing with lvs, narrow-cylindric. ♂ catkins to 4 cm long, spreading and often tending to curve downwards; rachis villous. Bracts 2-4 mm long, ovate-elliptic, elliptic-oblong or ± oblong, pale green, hairy; margins strongly incurved; apex obtuse or acute. Glands 2, the larger anterior one 0.4-0.5 mm long, oblong to square. Stamens 2; filaments hairy towards base. ♀ catkins similar to ♂; gland 1 (anterior), 0.4-0.5 mm long, broader than long to semi-annular. Ovary sessile, glabrous.
Key
FL Sep-Oct.
Unlike S. fragilis and most plants of S. × rubens, trees of S. alba have whitish rootlets when these are in water and the abundant willow sawfly galls on the lvs are pale greenish or pale yellowish. Wild N.Z. plants of S. alba can be referred to 2 vars and some plants to particular cvs of them.
