340 
THE FERNS OF SOUTH AFRICA 
nor to any other related genus. The numerous species grow 
on damp ground, or in water, and are distributed over 
America, Europe, Africa, Australia, and New Zealand. 
A good many species occur in North Africa, and south 
to Angola, and they vary immensely in accordance with the 
supply or absence of water. 
217. ISOETES NATALENSIS Baker. 
Plate 184. Fig. 2. B Sporangium, enlarged. 
Plant three to four inches high. Rootstock three-lobed. 
Leaves ten to twenty, ascending or erect, very slender (quarter 
line diameter), rush-like, pale green, opaque, firm in texture, 
two to four inches long, rounded on the back, channelled 
down the face, furnished with stomata and accessory bast- 
bundles. Sporangium small, globose, brownish ; veil none. 
Macrospores white, with small tubercles between the ribs, 
and large ones over the remainder of the surface. Micro- 
spores granulated. A small rush-like plant, growing in 
constantly wet ground not often flooded. 
Natal. — Griffin’s Hill, Eastcourt (Rehmann, 7296); Upper Mooi River, 
near the Berg (T. R. Sim). 
218. ISOETES WORMALDII Sim. (New species.) 1 
Plate 185. Nat. size. B Sporangium, nat. size. C Macrospore, 
much magnified. 
Rootstock three-lobed; leaves fifty to seventy, ligulate- 
1 218. Isoetes Wormaldii Sim. (Species nova.) 
Tab. 185. Mag. nat. B Sporangium, mag. nat. C Macrospora, 
multum amplific. 
Rhizoma trilobatum ; folia 50 — 70, ligulato-teretia seu planiuscula, 9 — 18" 
longa, diametro, ad apicem rotundatum vix attenuata, flaccida, ad summam 
aquam surgentia, deinde natantia magisque extensa ; pavtibus submersis desunt 
stomata ; partes natantes atrovirides ac gramineae ; nervi unus medianus, unus 
marginalis utrinque undique ; vagina folii membranacea, dilatata, margines com- 
plectentes et ad dimidium obtegentes sporangia in superficie superiore ; sporangia 
plerumque prolata in basi singulorum foliorum, longa, lata, membranacea, 
exteriora macrosporas paucas, interiora microsporas numerosas continentia; macro- 
sporae albentes, durae, trisulcatae, tuberculatae ; microsporae minutissimae. 
In stagnis prope East London: ibidem, in Victoria Park. Primum inventa a 
W. H. Wormald, Dec. 1893. 
Abundans in stagnis supra dictis, 1902 (T. R. Sim, 1567). 
