Lejeunea (sect. Flavae) R. M. Schust.

[Clade XI]Lejeunea sect. FlavaeR. M. Schust. (Schuster 1980: 941) Nesolejeunea Herzog (Herzog 1947: 327) – Type species: N. intercalaris Herzog (= L. acuta Mitt.). Type species Lejeunea flava (Sw.) Nees. Description Plants prostrate, glossy yellowish green, autoicous or dioicous. Stems with ca 10–16 rows of medullary cells. Leaves symmetrically ovate, apex usually rounded, rarely acute (L. acuta). Leaf cells with distinct trigones and intermediate thickenings. Cuticle mostly smooth, occasionally roughened by wax crystals. Oil bodies finely granular, 2–10 per cell. Lobules small, ca 1 / 4 × leaf length. Underleaves rather large, 3–6 × stem width, frequently imbricate. Male bracteoles restricted to the base of the male spike (exceptionally present throughout: L. brenanii E. W. Jones). Gynoecial innovations usually fertile but not repeatedly, with up to 2 gynoecia in a row. Perianths with 5 ± smooth keels, rarely eplicate (L. ramosissima Steph.). Asexual reproduction by specialized devices absent. Distribution Pantropical; centre of species diversity in tropical Africa (Jones 1968). Species Lejeunea acuta, L. brenanii, L. flava, L. isophylla E. W. Jones, L. lomana E. W. Jones, L. ramosissima Steph., L. tuberculosa Steph. Notes The main characters of sect. Flavae are the rather unspecialized, prostrate, glossy yellowish-green plants with rather large underleaves (3–6 × stem width), leaf cells with distinct trigones, finely granular oil bodies, and 5 - keeled perianths with ± smooth keels. References Jones (1968), Schuster (1980), Wigginton (2004).