Psilotaceae - Whisk ferns
Photo: BT. Wursten
Description of the family
Epiphytic or lithophytic perennial plants. Rhizome shortly creeping, dichotomously or laterally branched, with endophytic mycorrhiza, without roots, with short and long rhizoids. Aerial stems linear, chlorophyllous, erect or pendulous, dichotomously branched, simple towards the base. Leaves much reduced, simple, scale-like, lacking a midrib, without ligules. Sporangia in globular, thick-walled synangia composed of 2 or 3 fused sporangia, exindusiate, homosporus.
Worldwide: 2 genera and 12 species. Tmesipteris confined to tropical Asia and western Oceania, Psilotum has a pantropical distribution.