| 释义 |
‖ protonema Bot.|prəʊtəʊˈniːmə|
Pl. -ˈnemata. Also (in mod. Dicts.) in anglicized form protoneme |ˈprəʊtəʊniːm|.
[mod.L., f. Gr. πρωτο- proto- + νῆµα thread.]
In mosses (and some liverworts), The confervoid or filamentous thallus which arises from the germination of the spore, and produces the full-grown plant by lateral branching. (Also called pro-embryo.)
1857Berkeley Cryptog. Bot. §509. 462 This mass..is called the Protonema, and is always distinguished by the cells containing chlorophyl. 1858Carpenter Veg. Phys. §738 When the spores of mosses are sown they do not..directly produce a young moss, but they put forth conferva⁓like filaments, which are called the protonema. 1875Bennett & Dyer Sachs' Bot. 150 A new Moss-plant is..constituted by the formation of a leaf-bearing shoot out of a branch of the alga-like Protonema, which branches, strikes root (by root-hairs), and is independently nourished.
Hence protoˈnemal, protoˈnematal adjs., pertaining to or of the nature of a protonema; protoˈnematoid a., resembling a protonema.
1875Bennett & Dyer tr. Sachs's Text-bk. Bot. ii. 318 These latter [leaves] then put forth protonemal filaments, which produce first of all a flat pro-embryo; and upon this finally new leaf-buds arise. 1900Nature 9 Aug. 340/1 Leaves which,..with greater or less intervention of protonematal filaments give birth to new individuals. 1938G. M. Smith Cryptogamic Bot. I. ii. 135 The protonematal initial develops into a green filament (the primary protonema), also differentiated into nodes and internodes. 1958Nature 19 Apr. 1139/2 In the course of studies on protonematal regeneration and growth in the moss Splachnum ampullaceum (L.) Hedw., the effect of gibberellic acid on the growth of the protonemata was also tested. 1969F. E. Round Introd. Lower Plants viii. 101 The protonemal stage is..generally ignored in the description of liverworts. |