Labellar features of C. membranacea (SEM). (A–I) Labellum bearing clavate projections (osmophores) that are concentrated distally and centrally. (B) Epidermal cells of distal, adaxial surface of labellum showing striated cuticle. (C) Detail of typical, unbranched, multicellular, clavate osmophore. Note the narrow, elongate stalk cells and the isodiametric head cells. (D) Detail of head showing angular cells with striated cuticle and scant residues of secreted material. (E,F) Osmophores with bifid heads. (G) Branched, deeply bifurcate osmophore. (H) Flabelliform, laterally compressed osmophore. (I) Osmophore with head composed of three confluent lobes. Scale bars: (A, H) = 1 mm; (B) = 20 µm; (C, F) = 100 µm; (D) = 10 µm; (E, I) = 500 µm, (G) = 200 µm.