Family : Orchidaceae
Text © Prof. Pietro Puccio
English translation by Mario Beltramini
The species is native to Borneo, Java, Peninsular Malaysia, Philippines and Sumatra where it lives on the trees of the humid forests, frequently of Dipterocarpaceae, between the 400 and the 2700 m of altitude.
The name of the genus is the combination of the Greek substantives “βολβός” (bolbos) = bulb and “φύλλον” (phyllon) = leaf, with reference to the leaves growing at the apex of the pseudobulbs; the name of the species is the present participle of the Latin verb “flavescere” = to become yellow, with reference to the colour of the flowers.
Common names: yellowish bulbophyllum (English).
The Bulbophyllum flavescens (Blume) Lindl. (1830) is an very variable epiphytic species that forms wide tufts, on the trunk as well as on the main branches of the trees, with tiny close pseudobulbs on a creeping rhizome.Ovate-lanceolate leaves with acute or obtuse apex and gradually thinned base, 5-20 cm long and 1,5-2,5 cm broad, of intense green colour, coriaceous.
Racemose inflorescence, on a thin 3-8 cm long scape, bearing numerous tiny flowers, of about 2 cm of diameter, of pale yellow colour with pale orange apex of the labellum. Lanceolate dorsal sepal with caudate apex, concave, 0,7-0,8 cm long, lanceolate lateral sepals with acute or caudate apex slightly longer than the dorsal one, united at the base of the column to form a sort of a spur (mentum), linear-lanceolate petals with acute apex, about 3 mm long and 1 mm broad, ovate labellum with obtuse apex and ciliate margins, abruptly bent at the centre, about 3 mm long and 1 mm broad, and column with bifurcated apex.
It reproduces by seed, in vitro, and by division, with each section provided of at least 3-4 pseudobulbs, at the vegetative restart.
Floriferous and easy to cultivate miniature orchid, requires a partial shade, medium-high temperatures in summer, 20-30 °C, slightly cooler in winter, with lowest night ones not under the 15 °C, high humidity, 70-80%, and constant ventilation.
The plants mounted on trunks or rafts are to be watered and nebulized frequently, utilizing rain water, demineralized or by reverse osmosis at ambient temperature.
The waterings must be more reduced, in order to allow the substratum to partly dry up, for the plants cultivated in pots or baskets. Fertilizations every two weeks from spring to autumn, monthly in winter, utilizing a balanced hydrosoluble product, with microelements, at 1/4 the dosege shown on the package.
The species is reported in the appendix II of the CITES (species whose trade is internationally ruled).
Synonyms: Diphyes flavescens Blume (1825); Bulbophyllum adenopetalum Lindl. (1842); Phyllorchis adenopetala (Lindl.) Kuntze (1891); Phyllorchis flavescens (Lindl.) Kuntze (1891); Phyllorkis adenopetala (Lindl.) Kuntze (1891); Phyllorkis flavescens (Blume) Kuntze (1891); Bulbophyllum montigenum Ridl. (1894); Bulbophyllum puberulum Ridl. (1896); Bulbophyllum barrinum Ridl. (1912); Bulbophyllum ramosii Ames (1912); Bulbophyllum lanceolatum Ames & C.Schweinf. (1920); Bulbophyllum exiliscapum J.J.Sm. (1927).