The Collaborative International Dictionary
Didymous
Didymous \Did"y*mous\ (d[i^]d"[i^]*m[u^]s), a. [Gr. di`dymos twofold, twin.] (Bot.) Growing in pairs or twins. [1913 Webster] ||
Wiktionary
didymous
a. (context botany zoology English) twin, twinned; growing or occurring in pairs.