Of the eight species of the Tetragonostachys that occur in Africa and on Madagascar only the species
Selaginella wightii occurs outside of the area in southern India and on Sri Lanka. Understandably the African and
Asian populations have been classified into two varieties based upon the degree of cilia on the sporophylls.
These varieties are: S. wightii var. wightii, the Asian species, and S. wightii var. phillipsiana, the
African species, which has been recently classified as its own species in The Flora of East Africa, by Bernard
Verdcourt (
http://en.wikipedia.org/wiki/Bernard_Verdcourt) and is so regarded by Michael Hassler and Brian Swale in their Checklist of World Ferns website (
http://homepages.caverock.net.nz/~bj/fern/).
In an email from Roy Gereau, a specialist in pteriodophytes working for the Missouri Botanical Gardens in the USA, he points out that in Dr. Verdcourt's Flora the species S. wightii does not occur on the African continent but does on Mauritius
whereas Hassler & Swale notes S. wightii as occurring in Tanzania. However, based upon notes by Rolla M. Tryon, Jr. the distinction between S. wightii and S. phillipsiana does not appear to warrant segregation of the
established two varieties without futher delineation, so I am maintaining S. phillipsiana as a variety of S. wightii.
The species is monomorphic in character with the microphylls generally being of the same size and shape
at the same position around a stem. The stems appear to be creeping and possess upright strobili.
Here is an image of the Asian variety taken in Sri Lanka:
http://www.odu.edu/~lmusselm/plant/index.php?todo=details&id=8826S. wightii appears to be found only in the temperate highlands of southern Sudan, southern Ethiopia, marginally into northwestern Somalia occurring in rocky habitats at 1200-1900 meters (3937-6234 ft)*, western Kenya, and into northeastern Tanzania, as per Mr. Gereau's email of Dr. Verdcourt's findings, found only at two locations at elevations of 900 to 1200 meters (2953-3937 ft). The climate in the areas of occurrence is very moderate varying from averages of 15 C to 25 C (59 F to
77 F). The daily change in temperature can be as much as a 12 degree rise from the morning lows.
Monsoonal rains occur twice during the year with heavier rains occurring roughly during April into June produce
by the southwest monsoon and a lighter monsoonal flow during October into December. High humidities and
fog banks upon the mountain plateaus serve to help cool the area.
The species may be found as cushions sprawling over rocks and among outcrops at elevations ranging from
900 meters (21953 ft) to 2400 meters (7874 ft), as per Mr. Gereau's email of Dr. Verdcourt's findings.
It has been collected on Mt. Kilimanjaro as recently as 2001, being found at 1600 meters (5249 ft).
There are no other images currently available for free view on the net apart from the one noted above.
There are two available herbarium specimens that can be enlarged with their magnification tools.
The best view is of the speciment collected in India by R. M. Tryon Jr. at the Berlin Herbarium
http://ww2.bgbm.org/herbarium/view_large.cfm?SpecimenPK=98227&idThumb=275865&SpecimenSequenz=1&loan=0and another Indian specimen collected by Robert Wight, who collected in India from 1826 to 1828, is
housed at the New York Botanical Garden Herbarium
http://sweetgum.nybg.org/vh/specimen.php?irn=721083*from Selaginella in Flora of Somalia vol. 1 (1993) by Dr. Mats Thulin per email from Dr. Thulin. Dr. Thulin
also accepts the taxon designation as Selaginella phillipsiana.
A special thanks to Roy Gereau and Mats Thulin for contributing information to this post.