Psilotum

Psilotum nudum

Psilotum is one of two genera of the family of fork -leaved plants ( Psilotaceae ). Your are attributed to two types.

Description

Psilotum species are herbaceous plants which do not form roots. The underground parts of the stems are highly branched and form gems. The above-ground stems are slender, well developed, dichotomous branching and can grow up to 1 m in length, but are usually shorter. The leaves are pfriemförmig or scale-like. They have no veins, or this is weak at the base.

The sporangia are sessile or nearly sessile, at first spherical, three-lobed or later dreizellig. The spores are elliptical and coarsely wrinkled.

Systematics and distribution

The genus Psilotum consists of two types:

• Psilotum nudum (L.) Beauv P., Occurrence:. Distributed worldwide in the tropics and subtropics, with the exception of arid regions. It extends into the southeastern United States, the center of Japan and South Korea. Also on some often remote islands, especially in the Pacific it occurs. In Europe there is an occurrence in south-western Spain at Algeciras.
• Complanatum Psilotum Sw. ( Syn: Psilotum flaccidum Wall. ) Occurrence: mainly in the Pacific, Jamaica, Mexico, Central America, South America, Malaysia, and on some Pacific islands.
• Psilotum x intermedium WHWagner ( Psilotum Psilotum nudum complanatum × ): from Hawaii has been described between the two species, the hybrids.