gametophyte vegetative stage protonema whole plant development stage 2011-03-10T11:37:59Z protonemal phase (exact) The protonema phase ends with the development of gametophores in mosses, some other bryophytes, and leptosporangiate ferns and with the development of a thallus in other bryophytes, although protonema tissue may persist of continue to develop after this. fase protonemica (Spanish, exact) PO:0030006 原糸体を形成する植物発生段階 (Japanese, exact) rwalls PO_GIT:300 A gametophyte development stage during which a gametophyte undergoes filamentous growth and that succeeds spore germination and precedes a thalloid development stage (planar growth) or gametophore development stage. protonema phase (exact) plant_structure_development_stage