gemma

Etymology

Learned borrowing from Latin gemma (“bud on a plant”). Doublet of gem and Gemma.

noun

1. (biology) An asexual reproductive structure, as found in animals such as hydra (genus Hydra) and plants such as liverworts (division Marchantiophyta), consisting of a cluster of cells from which new individuals can develop; a bud.
   I know of no other genera with such intramarginal formation of true gemmae. 1969, Rudolf Mathias Schuster, The Hepaticae and Anthocerotae of North America East of the Hundredth Meridian, volume 1, Columbia University Press, page 527
   Gemmae are frequently longer than wide or of irregular shape. According to Degenkolbe, gemmae-bearing leaves are always different in form from normal leaves. 1990, Anthony John Edwin Smith, The Liverworts of Britain and Ireland, page 2
   In Marchantia polymorpha, high temperature promotes germination of gemmae (Dacknowski, 1907), and heat absorbed by the gemmae accelerates their germination (Fitting, 1942). 2005, R. N. Chopra, Biology of Bryophytes, page 32