Maths encyclopedia and lessons  
Search

Mathematics Encyclopedia and Lessons

 
     
 

Lessons

Popular
Subjects

algebra
arithmetic
calculus
equations
geometry
differential equations
trigonometry
number theory
probability theory
more
 

References

applied mathematics
mathematical games
mathematicians
more
 
 

Whisk fern

  • Psilotum nudum (L.) Beauvois
  • Psilotum complanatum Sw.

The whisk ferns, traditionally thought not to be true ferns, are odd, "primitive" vascular plants that reproduce solely by spores, without seeds. Recent evidence has suggested that they may in fact be ferns that have lost a number of pteridophytic characteristics, but their status is still uncertain.

There are two species, as listed in the taxobox, with a hybrid between them known, Psilotum x intermedium W. H. Wagner.

The distribution of Psilotum is tropical and subtropical, in the New World, Asia, and the Pacific. The highest latitudes known are in South Carolina and southern Japan for P. nudum.

01-04-2007 01:18:14
The contents of this article are licensed from Wikipedia.org
under the GNU Free Documentation License. How to see transparent copy