Jensenia

Jensenia
Scientific classification
Kingdom:	Plantae
Division:	Marchantiophyta
Class:	Jungermanniopsida
Order:	Metzgeriales
Family:	Pallaviciniaceae
Genus:	Jensenia Lindb. 1868
Species
Jensenia angulata Jensenia canicruria Jensenia decipiens Jensenia difformis Jensenia erythropus Jensenia lewisi Jensenia pisicolor Jensenia spinosa
Synonyms
Makednothallus Mittenia

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. The six or seven species of the genus belong to a southern, possibly Gondwana element.

General characteristics

Jensenia liverworts are dioicous. Compared to Pallavicinia liverworts, 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.

Reproductive morphology

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.