By Thomas Silou, Laurent Loubaki, Gilles Figuérédo and Jean-Claude Chalchat

Abstract: Abstract: Seventy constituents were identified by GC and GC/MS analysis of the oils from the leaves and flower tips, stalks and roots of Elyonurus hensii Schum. The compounds p-cymene, p-mentha-2,8(9)-dien-1-ol, p-mentha-1(7),8-dien-2-ol, 2-undecanone, 2-tridecanone, intermedeol and aristolone characterize and discriminate the underground and aerial parts of the plant. Key Word Index: Elyonurus hensii, Graminae, essential oil composition, p-cymene, p-mentha-1(7),8-dien-2-ol, aristolone.

Introduction
Elyonurus hensii Schum is a grass found in the tropical zone of the Democratic Republic of Congo, Republic of Congo and Gabon. In the Republic of Congo it grows in the low-Congolese climate on clay-sand to moist sand soils. Its height does not exceed 1 m, and its fine stalk is ramified at the top. Its roots are 4-8 cm long and are fine and flexible. Its leaves are 8-15 cm long and 2 cm wide, and scrolled. Its stem is nonvillous. It is used in the Congo as an herbal tea to treat aches and influenza-like conditions. The oils of E. hensii have not been studied to date. As a result, we report here the chemical composition of oils obtained from leaves with flowering tips, stalks and roots.