296 
THE FERNS OF SOUTH AFRICA 
§§ Pinnules much longer than broad. Sorus medial on a veinlet. 
(Mertensia.) 
178. G. umbraculifera. Pinnules occurring on all the dicho- 
tomous branches. 
179. G. linearis. Pinnules on the terminal pinnae, but absent 
from the lower dichotomous branches, where each fork is sub- 
tended by a pair of small pinnated pinnae. 
177. Gleichenia polypodioides (Linn.) Smith. 
Plate 156. Nat. size, b Part of pinna, magnified, c Capsule, 
much magnified. 
Rhizome very long, often four to six feet, much branched, 
slender, about one line diameter, when old, brown and polished, 
like stout copper wire, but when young covered with star-like 
tufts of black hairs. The rhizome mostly runs along the 
surface of the soil, rooting down into it, but is sometimes 
scandent or sub-scandent, or hanging in masses over the top 
of a rock. Fronds one to three feet long, on brown polished 
stalks, which are either hairy at the base only, when quite 
young, and afterwards glabrous, or else woolly-tomentose, 
especially at the forks. Frond dichotomously branched several 
times, the ultimate branches, as well as all the branches down 
to the first fork, set with numerous pinnately arranged pinnae, 
one to four inches long, two to three lines broad, divided 
down to the rachis into closely set, bluntly-pointed pinnules, 
one line broad, one to one and a half lines long. The central 
buds in the lower dichotomous forks frequently develop into 
branches, again repeatedly dichotomous, but without pinnae 
along the main rachis. Fronds are green on the upper, and 
more or less glaucous on the under surface. In young plants 
the pinnules are frequently four to five lines long, but as the 
plant gets older the pinnules become shorter and more rounded. 
The sori are sunk, pit-like, into the substance of the frond, 
one in the upper axil of each fertile pinnule, at the end of a 
veinlet, and contain three to four large capsules each, which 
fall off soon after midsummer. 
Schlechtendal makes two varieties, viz. : 
a. vulgaris. Pinnules green on underside. 
j8. arge?itea. Pinnules glaucous on underside. 
