The Collaborative International Dictionary
Triadelphous
Triadelphous \Tri`a*del"phous\, a. [Pref. tri- + Gr. ? brother.] (Bot.) Having stamens joined by filaments into three bundles. See Illust. under Adelphous.
Wiktionary
triadelphous
a. (context botany English) Having its stamens fused together at least partly by the filaments so that they form three separate groups, some of which may contain a lone stamen.