LEAF ANATOMY OF RAOULIA HOOK.F. (COMPOSITAE, GNAPHALIEAE)

Leaf anatomy is compared for all species of Raoulia. The species are t abulated according to their lamina structure. Noteworthy anatomical fe atures are lamina type and grade of differentiation, stomatal position , epidermal and cuticle thickness, shape of mesophyll cells, presence or absence of central clear cells, sclerenchyma caps, abaxial collench yma and protruding midrib. It is shown that leaf anatomy data provide characters which are taxonomically useful in Raoulia. The main subgene ra are supported except that the leaf anatomy of R. haastii is anomalo us and that of R. youngii is typical of R. subg. Raoulia rather than R . subg. Psychrophyton. The leaf anatomy of R. petriensis is unique in the genus. (C) 1998 The Linnean Society of London.