Friday, February 21, 2014

[Orchidology • 2013] Vanilla atropogon • a new species from Khanh Hoa Province, Vietnam

Vanilla atropogonin situ inflorescence.
Photo: Romana Rybková

 Vanilla atropogon a new species from Khanh Hoa Province, Vietnam is described.
Keywords: Vanilla atropogon, Orchidacea, Khanh Hoa Province, Vietnam

Etymology. From atro-, dark, and pogon, beard, referring to the dark, hairy lip. 

Distribution. Vietnam (Khanh Hoa Province). Endemic. 

Notes. Vanilla atropogon is perhaps most closely related to V. borneensis Rolfe (syn. V. pilifera Holttum), which has flowers that are similar in size, shape and ornamentation. In V. borneensis the patch of hairs on the mid-lobe is much denser, with hairs of almost uniform thickness (versus hairs strongly narrowing towards the apex in V. atropogon) and this patch is almost or entirely contiguous with the central patch of scales; in V. atropogon the patch of hairs and the callus-like patch of scales are well-separated; in V. borneensis the basal part of the lip is much broader and is provided with two knob-like calli, which are lacking in V. atropogon. The colour of the lip is quite different in V. borneensis: white with pink or purple veins and pink hairs. Finally, the inflorescence of V. borneensis carries 5–12 (V. atropogon: 10–23) flowers. 
 The unusual colour of the lip of V. atropogon in combination with the bad smell of the flowers suggests that it may be pollinated by flies. Unfortunately, nothing is known about the pollinators of other Asian species, but most are likely to be bee pollinated, as has been observed in similar-looking tropical American species (Cameron, 2011).

André Schuiteman. Leonid Averyanov & Romana Rybková. 2013. Vanilla atropogon, a new species from Vietnam. Orchideen. 1-1; 10-16.