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

India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...

China China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...

Myanmar Myanmar, officially the Republic of the Union of Myanmar; and also referred to as Burma (the official English name until 1989), is a country in northwest Southeast Asia. It is the largest country by area in Mainland Southeast Asia and has ...

, and

Nepal Nepal, officially the Federal Democratic Republic of Nepal, is a landlocked country in South Asia. It is mainly situated in the Himalayas, but also includes parts of the Indo-Gangetic Plain. It borders the Tibet Autonomous Region of China Ch ...

. It is closely related to '' Papilionanthe biswasiana''.

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 90 species, and the genus is commonly cultivated for the marketplace. This genus and its allies are considered to be among the ...

'' 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