Its large, fleshy, tuberous root, often 2 feet long, produces several round, purplish, trailing or somewhat climbing stems bearing alternate, broad-ovate and cordate or sometimes fiddle-shaped (pandurate) leaves.
-- John Lust, The Herb Book, 1974
The lip is pandurate with a broadly expanded, erose, apical lobe, separated from obtuse lateral lobes by a very narrow isthmus.
-- Carlyle A. Luer, A First Century of New Species of Stelis of Ecuador, 2002
Pandurate comes from the Latin pandūra, a three-stringed musical instrument popular in ancient times.