[1] : The Collaborative International Dictionary of English v.0.48

gemma \gem"ma\, n.; pl. gemmae. l., a bud.
   1. bot. a leaf bud, as distinguished from a flower bud.
      1913 webster

   2. biol. a bud spore; one of the small spores or buds in
      the reproduction of certain protozoa, which separate one
      at a time from the parent cell.
      1913 webster
see also:
gemmae 

[2] : WordNet (r) 2.0

gemma
     n : small asexual reproductive structure in e.g. liverworts and
         mosses that detaches from the parent and develops into a
         new individual
     also: gemmae pl
see also:
gemmae 

Gemma >> G Words
Gemma, definition of term: Gemma
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