Definition of protonema in English:

protonema

noun

Botany
  • 1The juvenile form of a bryophyte (usually consisting of a branched filamentous structure, but sometimes flat or platelike), developing on the germination of a spore and producing buds from which the adult plants arise.

  • 2An analogous thread-like structure in other lower plants; specifically the filamentous form of a developing gametophyte of a fern or charophytic alga.

Origin

Mid 19th century; earliest use found in Miles Berkeley (1803–1889), Church of England clergyman and naturalist. From scientific Latin protonema, former genus name from proto- + -nema.

Pronunciation

protonema

/ˌprəʊtə(ʊ)ˈniːmə/