The Collaborative International Dictionary
Hyponastic
Hyponastic \Hy`po*nas"tic\, a. [Pref. hypo- + Gr. ? pressed close.] (Bot.) Exhibiting a downward convexity caused by unequal growth. Cf. Epinastic.
Wiktionary
hyponastic
a. (context botany English) Exhibiting a downward convexity caused by unequal growth.