''Papilionanthe vandarum'' is a species of epiphytic orchid native to

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

Myanmar Myanmar, ; UK pronunciations: US pronunciations incl. . Note: Wikipedia's IPA conventions require indicating /r/ even in British English although only some British English speakers pronounce r at the end of syllables. As John C. Wells, Joh ...

, and

Nepal Nepal (; ne, नेपाल ), formerly the Federal Democratic Republic of Nepal ( ne, सङ्घीय लोकतान्त्रिक गणतन्त्र नेपाल ), is a landlocked country in South Asia. It is mai ...

. Is is closely related to ''

Papilionanthe biswasiana ''Papilionanthe biswasiana'' is a species of epiphytic orchid native to Laos, China, Myanmar, and Thailand. Is is closely related to ''Papilionanthe vandarum''. Description It is erect or pendulous, slender, long, wide, usually unbranched stem ...

''.

Description

This species is adapted to drought and can grow in full sun. Flexible, long and slender stems bear terete, distichously arranged leaves with cuticular papillae and specialised, club-shaped water-storage cells are found within the mesophyll. The cuticle is very thick and may reach a thickness of 19 µm on the adaxial leaf surface and 17.5 µm on the abaxial leaf surface. Few flowers, resembling ''

Vanda ''Vanda'', abbreviated in the horticultural trade as ''V.,'' is a genus in the orchid family, Orchidaceae. There are about 87 species, and the genus is commonly cultivated for the marketplace. This genus and its allies are considered to be among ...

'' flowers, hence the specific epithet ''vandarum'', are produced on axillary racemes. The floral morphology of the fragrant, predominantly white flowers infers entomophily and they are thought to be pollinated by moths. The three-lobed labellum bears a 1.6 cm long, slender, bent or curved spur, which has unicellular, or occasionally bicellular, secretory trichomes. Spindle-shaped, 0.3 mm long seeds with pointed ends are formed in capsules.

Ecology

The plants may grow at altitudes of 1028 to 1740 m a.s.l. and flowering occurs in May to September or June to July.

Conservation

This species is rare and endangered.Kishor, R., Devi, H.S., Jeyaram, K. et al. Molecular characterization of reciprocal crosses of Aerides vandarum and Vanda stangeana (Orchidaceae) at the protocorm stage. Plant Biotechnol Rep 2, 145 (2008). https://doi.org/10.1007/s11816-008-0053-8

Images

Papilionanthe vandarum (Rchb.f.) Garay, Bot. Mus. Leafl. 23 372 (1974) (45631410074).jpg Papilionanthe vandarum (Rchb.f.) Garay, Bot. Mus. Leafl. 23 372 (1974) (45442100285).jpg Papilionanthe vandarum (Rchb.f.) Garay, Bot. Mus. Leafl. 23 372 (1974) (45442137455).jpg Papilionanthe vandarum (Rchb.f.) Garay, Bot. Mus. Leafl. 23 372 (1974) (44537733970).jpg The Orchid Album-03-0064-0116-Aerides vandarum.png

References

vandarum Orchids of India Orchids of Myanmar Orchids of China Orchids of Nepal {{Vandeae-stub