248 
The Ferns of South Africa. 
Tropics generally, and a little beyond them ; epiphytal on 
trees. 
Natal. — (Gueinzius), on the coast, rare ; bush swamp at head of Bay of 
Natal (Buchanan). 
Order IV. — Selaginellace^e. 
Genus XL1. — Selaginella. Spring. 
Plants very similar in habit to some species of Lycopodium, in 
which genus this was formerly included, and from which it is 
distinguished by having dimorphous spores and sporangia. Many 
species have procumbent rooting stems ; some have erect stems 
from spreading rhizomes, others have the stems proceeding from a 
crown, while a few are annual, and erect or procumbent. In 
almost all the species the leaves are distichous and dimorphous, 
though in a few the leaves are all alike and produced all round 
the stem. Sporangia one-celled, two-valved, arranged in the axils 
of bracts in spikes terminal on the branches. The smaller kind of 
sporangia, which contain numerous small spores occupy the upper 
part of the spike, and the larger kind occupy the lower part, and 
contain several large spores, which on development produce a 
minute prothalium, on which fertilisation takes place. The habit 
of growth in Isoetes is altogether different. 
Synopsis of the species. 
§ Leaves set all round the stem, and all of one kind. 
166. S. pumila. Annual, sub-erect, leaves not awned. 
167. S. rupestris. Perennial, procumbent, leaves awned. 
§§ Leaves of two kinds, one line of larger spreading leaves along both sides 
of the decumbent stem, and two lines of smaller ascending leaves on 
the upper surface. Perennials of firm texture. 
168. S. depressa. Stem not jointed, two to three inches long, slightly 
branched. 
169. S. Kraussiana. Stem jointed, six to twelve inches long, much 
branched. 
§§§ Leaves as in the previous section. Annuals of thin texture. 
170. S. integerrima. Leaves not ciliated at all. 
