ORCHIDACE^ 



Luzon, Rizal Province, M. Ramos Bur. Sci. ^JfOlO^ December 14, 1915. 

 Epiphyte in river forest. 



DENDROBIUM Sw. 



Dendrobium (§ Ceratobium) busuangense Ames sp. nov. 

 Caules elongati, 2 m. alti vel altiores, ±1 cm. in diametro, flavidi, 

 foliosi. Folia ±7.5 cm. longa, ±4.5 cm. lata, elliptica, obtusa, valde 

 coriacea, in sicco prominenter nervosa, inaequaliter bilobulata. 

 Vaginae tubulatae, internodiis subaequilongae vel paulo brevi- 

 ores. Inflorescentiae laxe racemosae, plus minusve quindecim- 

 florae, pedunculo tereti, ±5 dm. longo, nonnullis vaginulis tubu- 

 latis donato, rachide circa 2 dm. longa. Bracteae inflorescentiae 

 triangulares, acutae, 3 mm. longae. Pedicellus cum ovario gra- 

 cilis, 4-5 cm. longus. Sepala lateralia 2.5 cm. longa, triangularia, 

 obtusa, apiculata, cum pede gynostemii mentum 1 cm. longum 

 acutum formantia. Sepalum dorsale 2.5 cm. longum, 8 mm. la- 

 tum, oblongo-lanceolatum, obtusum, septemnervium. Petala 3. 5- 

 3.8 cm. longa, 5 mm. lata, erecta, torta, baud undulata, oblonga, 

 obtusa. Labellum 3.2 cm. longum, trilobulatum, subtus canali- 

 culato-concavum, supra tricostatum costa intermedia apice ali- 

 formi-elevata ; lobi laterales semiovati, margine undulati et irreg- 

 ulariter denticulati ; lobus medius ±1 cm. longus, vix 1 cm. latus, 

 oblongus, obtusus. Gynostemium bialatum. Clinandrium dentic- 

 ulatum. 



Dendrobium busuangense is a near ally of Z). conanthum Schltr. 

 The general aspect and habit of the plant suggest D. taurinum 

 Lindl., the only other representative of the section Ceratobium 

 known to occur in the Philippine Islands, but it is easily distin- 

 guishable from that species by the very different labellum and by 

 the color of the flowers. The sepals and mentum are very pale 

 lavender-purple. The twisted petals and the labellum are green- 



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