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Home /Anomalous_Items / Aquatic_Macrophytes / Submerged_Leaves / Vallisneria / Images |
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Vallisneria |
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Vallisneria
gigantea (a.k.a. V. americana)
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Vallisneria
gigantea
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Vallisneria
spiralis
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Vallisneria spiralis |
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Diagram of hydrophilous pollination. Cox, P.A. 1988. Hydrophilous pollination. Annual Review of Ecology and Systematics, Vol. 19, (1988), pp. 261-279. In the scenario, both male and female flowers are produced underwater and float to the surface. Female flowers remain attached to the plant on thread-like elongate peduncles, while male flowers detach and independently float to the surface and drift. Some are eaten by small fish. Surviving male flowers produce erect anthers above the water surface, some of which drift toward the floating female flowers that form a depression on the surface film -- down which the males slide to pollinate the females. Pollination is aerial, not underwater. Similar to all angiosperms (and gymnosperms) fertilization occurs when the pollen tube nuclei fuse with egg nuclei. After fertilization the developing fruits are no longer floating on the surface tension, and so continue to ripen underwater (Fassett 1940). Fassett, N.C. 1940. A Manual of Aquatic Plants. Univ. of Wisconsin Press. (405 pp.)
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Home /Anomalous_Items / Aquatic_Macrophytes / Submerged_Leaves / Vallisneria / Images |
