CAUDEX
caudex
(noun) woody stem of palms and tree ferns
stock, caudex
(noun) persistent thickened stem of a herbaceous perennial plant
Source: WordNet® 3.1
Etymology
Noun
caudex (plural caudices or caudexes)
(botany) An enlargement of the stem, branch or root of a woody plant, usually serving to store water.
Source: Wiktionary
Cau"dex, n.; pl. L. Caudices, E. Caudexes. Etym: [L.] (Bot.)
Definition: The sterm of a tree., esp. a sterm without a branch, as of a
palm or a tree fern; also, the pernnial rootstock of an herbaceous
plant.
Source: Webster’s Unabridged Dictionary 1913 Edition