Fig. 1

Eight species of Madagascan Bulbophyllum clade C vary intra-specifically for mating type. a Habit and detail of inflorescene (inset) and (b) flower close up of a member of Madagascan Bulbophyllum clade C (B. cirrhoglossum). c Outcrossing individuals (Type I) differ from their (d) auto-pollinating conspecifics (Type II) by the presence of the rostellum. Note that the pollinia in (d) were lost during sample preparation. Abbreviations: a, anther; c, column (gynostemium); l, labellum; p, pollinia; pe, petal; r, rostellum; rr rudimentary rostellum; s, stigma; se, sepal; st, stelidium. Scale bars: A = 20 mm; B = 1 mm; C, D = 0.1 mm. Photographs by A. Sieder (a) and A. Gamisch (b). The habitus photograph (a) and the scanning electron microscopy micrographs of B. quadrifarium and sketches of the different gynostemium morphs (c, d) are modified from [48]