Descriptions of the Species. 
47 
the vein, which becomes an elongated receptacle, surrounded by 
capsules on all sides, and often with a point extending beyond 
them. Capsules flattened, surrounded by an obliquely transverse 
entire ring, and bursting irregularly. The genus contains many 
species, mostly tropical or sub-tropical. 
Key to the species : — 
§ Fronds glabrous, not toothed. 
4. H. rarum, rachis winged, frond bipinnatifid, pinnules wide. 
5. H. gracile, rachis not winged, frond tripinnatifid, pinnules narrowly 
linear. 
§§ Fronds ciliated and hairy. 
6. H. obtusum, rachis winged, frond ovate-triangular. 
7. H. lineare, rachis not winged, frond linear lanceolate. 
§§§ Fronds toothed at the margin. (Leptocionium, Presl. ; and V. D. 
Bosch.) 
8. H. Tunbridgense, involucre toothed ; var. Wilsoni, involucre entire. 
4. Hymenophyllum rarum. R. Br. 
Plate 4, fig, 2, natural size. b pinnule, and involucre enlarged. 
Rhizome very slender, black. Stalk one inch long, slender. 
Frond pinnate, one to four inches long, four to eight lines broad 
at the base, tapering upward, pendant from the top of the stalk. 
Rachis winged for most of its length, pinnae neither toothed nor 
hairy at the edge, lower side undivided, upper side with three to 
five blunt pinnules, each one to three lines long, one line broad ; 
upper pinnae simple or forked, involucre inflated, wider and 
shorter than in the other species, lobes often one line broad, a 
half line long, divided to the lamina, and light coloured. 
Sori terminal on the upper pinnae, or on the pinnules nearest 
the rachis lower down. 
Some of the Table Mountain specimens are much larger than 
usual, four inches long, a half inch wide, and tapering below ; 
others one inch wide, and deltoid, but all having the involucre as 
wide as, or wider than, the segments. 
H. rarum. R. Brown in Prod. Flor. Nov. Holl. 159 ; Hk. and Bkr. 
Syn. Fil. 58 ; Pappe and Rawson, 137. 
H. semibivalve. Hk. and Gr. Ic. Fil., tab. 33. 
II. Thunbergii. Ecklon. (teste Kuhn, but not Schl, nor Kunze). 
