| Jensenia | |
|---|---|
| Scientific classification | |
| Kingdom: | Plantae |
| Division: | Marchantiophyta |
| Class: | Jungermanniopsida |
| Order: | Metzgeriales |
| Family: | Pallaviciniaceae |
| Genus: | Jensenia Lindb. 1868 |
| Species | |
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Jensenia angulata |
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| Synonyms | |
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Jensenia is a bryophyte plant genus in the liverwort family Pallaviciniaceae. It has been treated as a subgenus of Pallavicinia by several authors, though a set of features seems to set it apart as a genus.[1] The six[2] or seven[3] species of the genus belong to a southern, possibly Gondwanaland element.[1]
Jensenia liverworts are dioicous. Compared to Pallavicinia liverworts,[1][4] their thallus grows erect, and branches tree-like, rather than trailing the ground. The thallus is perched on an ascending stipe which grows from a creeping rhizome. Slime papillae are absent from the thallus margin, though locally present elsewhere. The midrib of the thallus is broad but ill-defined.
Male reproductive organs are scattered over the thallus's dorsal surface, while female organs are specifically placed near a bifurcation of the frond. The pseudoperianth, a tube of thallus tissue protecting the archegonia, is basally fused with the calyptra. Following fertilization, the sporophyte is enveloped by three structures: the cup-shaped involucre, cylindrical pseudoperianth and the calyptra. The spore surfaces are irregularly fasciated.