Orchid Information - Genus Dendrobium section Diplocaulobium subsection Goniobulbon

Genus Dendrobium Sw. sect. Diplocaulobium Rchb.f. subsect. Goniobulbon (Schltr.) de Vogel, Mal. Ochid J. 22 (2018) 83. Type species: Dendrobium chrysotropis Schltr.

Synonyms:

• Dendrobium sect. Goniobulbon Schltr. in K.Schum. & Lauterb., Nachtr. Fl. Deutsch. Schutzgeb. Südsee: 149 (1905)
• Diplocaulobium (Rchb.f.) Kraenzl. sect. Goniobulbon (Schltr.) Brieger (1981): 735, nom. illeg.

Plants epiphytic. Roots filiform, unbranched. Rhizome usually creeping, in some species pendulous; rhizome scales persistent or decaying. Pseudobulbs on a plant all of similar size and all potentially fertile, often crowded on the rhizome, in some species somewhat wider spaced, ovate to cylindrical, mostly 4-6-angular or –ribbed and ascending, in some species smooth and terete, in others dorso-ventrally flattened and appressed to the rhizome. Leaf normally erect, dorso-ventrally flattened, usually rather thin leathery, in some species thick coriaceous; in species with the pseudobulb dorso-ventrally flattened and appressed to the rhizome sometimes oblique and almost appressed to the substratum. Inflorescences usually arising in succession but sometimes in fascicles of 2-9; peduncle slightly shorter or longer than the spathe, with a terminal floral bract. Flowers usually rather small to medium-size, ephemeral, but in several species lasting several days, predominantly white with a more multi-coloured lip; not turning pink to purplish to the end of anthesis. Pedicel usually long, terete, sometimes with 6 ribs. Ovary with or without grooves, in some species 4- or 6-ribbed. Sepals and petals usually spreading widely. Median sepal erect or recurved, in some species horizontal. Lateral sepals falcate, widely opening, erect or recurved. Petals usually much more slender than the lateral sepals, erect or recurved. Lip either clearly divided in a hypochile with lateral lobes and an epichile, or ligulate without lateral lobes and without a clear division of the hypochile and epichile; keels on the hypochile 2 or 3, for most of their length straight or slightly curved, only in the upper part undulating or curved, keels on the epichile 3 or 5, in one species 4, usually more or less undulating over most of their length, the median one less so, in most cases keels glabrous, sometimes minutely papillose. Column compact, with curved column foot; clinandrium 3-lobulate; anther cap-shaped, in front usually truncate; pollinia 4.
(After De Vogel in De Vogel, Vugt & Hoogendijk 2018)

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