Osmunda (family Osmundaceae) A genus of large ferns with massive, erect rhizomes, and bi-pinnate leaves. The sporangia are borne mostly on the upper margins of specialized pinnules without lamina or chlorophyll, and are massive, short-stalked structures, cultivated as ornamentals (royal ferns). There are some 10 species, cosmopolitan in distribution but absent from Australasia.
More From encyclopedia.com
Quillwort , Isoetaceae A family of Pteridophyta, mostly aquatic vascular cryptogams with 2 types of spore (see HETEROSPORY). They have a short, stout, basal stoc… Pondweed , Potamogetonaceae (pondweeds) A cosmopolitan family of aquatic herbs, found mostly in fresh water, that have submerged and translucent or sometimes le… Centrifugal Speciation , centrifugal speciation The principle that new species are likely to arise towards the centre of the range of the present species, rather than at the… Vicarious Distribution , vicarious distribution The distribution that results from the replacement of one member of a species pair (i.e. two closely related species derived f… Selaginella , Selaginellaceae A family of the Pteridophyta in the wide sense, or of the Lycopsida in the narrower sense, of plants similar to the clubmosses (Lycop… Constellation Diagram , constellation diagram A representation of species affinities that is based on χ2 as a measure of the association between species. The reciprocal of t…
About this article
Updated About encyclopedia.com content Print Article
You Might Also Like