indumentumn.

1847 J. Lindley Elements Bot. (ed. 5) p. xlix Indumentum: The hairy covering of plants, of whatever kind.

1858 A. Gray Introd. Struct. & Systematic Bot. Gloss. 537/1 Indumentum, any hairiness or downy covering.

1930 J. B. Stevenson Species of Rhododendron 364 Under surface [of leaves of R. eriogynum] at first clad with a thin white flaking stellate indumentum easily rubbed off and quickly falling away.

1950 J. M. Cowan Rhododendron Leaf i. 1 On looking at the leaves of Rhododendrons, it will be seen that the under surface is often clothed with a hairy or scale-like covering, now loose and of a fine texture like a spider's web, now dense and compact like a thick felt or wool, now a mere sprinkling of brownish dots on a green background. This leaf covering, which is very variable, is known as the indumentum.

1963 P. H. Davis & V. H. Heywood Princ. Angiosperm Taxon. v. 155 To be of use for critical discrimination, indumentum must, of course, be described in detail, each type of hair present (and its disposition) being separately recorded.

1970 Watsonia 8 104 H[ieracium] termifrons occurs in two well-marked forms differing in shape of head and indumentum of the phyllaries.

1972 Biol. Abstr. 54 68/1 X[imenia] caffra differs from X. americana in that a dense or sparse indumentum is often present.