The thallus of the liverwort Marchantia polymorpha subsp ruderalis. The picture shows the upper surface of the leaf-like thallus, with many gemma cups

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The thallus of the liverwort Marchantia polymorpha subsp ruderalis. The picture shows the upper surface of the leaf-like thallus, with many gemma cups (circular outgrowths). The visible \liverwort plant\" is the gametophyte generation - in M polymorpha, plants are either male or female, and they produce gametes; either spermatozoids or oocytes. The picture is of a male plant, and no sexual tissues are visible. The gemma cups are a mechanism for vegetative propagation of the plant; the small green particles visible within most of the cups are gemmae. These are small propagules that are dispersed by means of rain splash, and can develop into independent new plants. It is primarily this mechanism that promotes the infestation of the surface of badly drained garden soils and damp soil in flower pots that results in Marchantia being a weedy pest species in many gardens."

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Size: 3468px × 5212px
Photo credit: © DR JEREMY BURGESS/SCIENCE PHOTO LIBRARY / Alamy / Afripics
License: Licensed
Model Released: No

Keywords: cup, gamete, gametophyte, garden, gemma, liverwort, marchantia, oocyte, polymorpha, propagule, ruderlais, spermatozoid, subsp, thallus, weed