Figure 1. Floral features of Bulbophyllum bicoloratum.

(A) Inflorescence with spirally arranged, resupinate flowers; (B) flower (ca. 4 x 6 mm) covered by an imbricate, oval-acute bract; (C) virtual 3D model generated by micro-CT of an auto-pollinated B. bicoloratum flower; (D) longitudinal section of the same 3D model passing through the median plane of the flower (see also Videos S1 and S2 corresponding to Figure 1C and D, respectively). In the 3D models, idioblasts with dense raphide-bundles are visible as white dots scattered throughout the non-reproductive floral tissue. Abbreviations: a, anther; c, column (gynostemium); dr, ‘displaced’ (suberect) rostellum; l, labellum; lig, ligament (hinge); o, ovary; p, pollinia; pe, petalum; s, stigmatic cavity; sc, stylar canal; se, sepalum; st, stelidium; sr, rim of stigmatic cavity; vb, vascular bundle. Photo credit Figure A, B: Rogier van Vugt (Leiden Botanical Garden).