Arachnis annamensis is a species of orchid, originated in Vietnam.

[1] It is a sizable monopodial orchid that thrives in warm climates, exhibiting epiphytic growth.

The elongated stem carries numerous alternate leaves, slightly bilobed at the apex.

It produces an upright inflorescence around 60 cm long in spring, with numerous flowers in the axils.

annamensis: Geographical epithet referring to its location in Annam in Vietnam.