Bulbophyllum trachypus Schltr., flowers, lateral view, photo E.F. de Vogel, Leiden cult.
Bulbophyllum trachypus Schltr., Orchid Monogr. 7 (1993) 88, fig. 48, J.J. Vermeulen, drawing, plant habit and flower analysis, based on a Schlechter 18573 (iso K); b-i Van Royen & Sleumer5934 (L)
Bulbophyllum trachypus Schltr., floral analysis, R. Schlechter in Repert. Spec. Nov. Regni Veg. Beih. 21 (1928) t. 307, fig. 1179
Bulbophyllum trachypus Schltr., herbarium sheet, Schlechter 18573 (isotype specimen K), photo copyright the Board of Trustees of the Royal Botanic Gardens, Kew