352 
I. FILICES. 
5. HYMENOPHYLLUM, Smith. 
Bhizome very slender, wiry, creeping. — Fronds usually matted, small (i-10 
in. long), pinnate or 2- or 3-pinnatifid, pale-green, pellucid, beautifully reti- 
culated when magnified ; segments with 1 stout, never branched midrib. Sori 
axillary or terminal, free or sunk in the segments, globose or oblong, enclosed 
in a 2-valved membranous involucre, whose lips open outwards. Capsules 
sessile on a stalked or filiform receptacle, depressed, girt by a complete hori- 
zontal striate ring. 
A very large tropical and temperate genus, of most beautiful small Perns. A few South 
American species have simple frouds. The species inhabit forests, often clothing stumps and 
trunks of trees. 
I. Fronds glabrous; margins toothed or serrate. 
Receptacle not exserted. 
Frond pinnate, pinnse pinnatifid. Invol. smooth, supra-axillary, 
valves jagged or toothed .. i ........ . 1. R. tunbridgense. 
Frond pinnate, pinnae pinnatifid. Invol. free, smooth, supra-ax- 
illary, valves quite entire 2. R. unilaterale. 
Froud minute, pinnatifid. Iuvol. terminal, free, with toothed 
backs and lips 3 . R. minimum. 
Frond 2- or 3-pinnatifid. Invol. terminal, base sunk in the 
frond, smooth ; lips quite entire 4. II. bivalve. 
Receptacle exserted. Involucre free 5. H. multifidum. 
II. Fronds glabrous, or setose only on the stipes, rachis and costa; margins neither toothed 
nor ciliate. 
Fronds pinnatifid, rarely pinnate below ; rachis and generally the stipes also winged. 
Rhizome and stipes capillary. Frond pendulous, flat, membranous. 
Invol. broad, flat, terminal, sunk in the frond 6. R. rarum. 
Rhizome stout, bristly. Frond tall, broad. Invol. orbicular, free, 
terminal 1. R. pulcherrimum. 
Rhizome stout, glabrous. Frond tall, 3-piunatifid. Invol. orbicu- 
lar, terminal, half sunk 8. R. dilatatum. 
Frond 3-pinnatifid ; segments and wing of rachis crisped or waved. 
Iuvol. ovate, free, terminal 9 . H. crispatum. 
Frond 3-pinnatifid ; segments narrow, concave. Invol. ovate, free, 
axillary 10. R. polyanthos. 
Frond pinnate below. Stipes not winged. Rachis winged above only. 
Stipes and rachis glabrous. Frond bright-green. Invol. small, ovate 11. H.demissum. 
Stipes and rachis bristly. Frond dark-green. Invol. orbicular . 12. H. scabrum. 
Stipes woolly at the base only and stipes glabrous. Frond pale, 
glistening. Invol. small 13. H. fiabellatum. 
III. Costa, margius and sometimes both surfaces of the fronds covered with stellate hairs. 
Frond pendulous, opaque, clothed with red-brown stellate hairs . . 14. II. ceruginosum. 
Frond pendulous, membranous, transparent ; margins and costa with 
stellate hairs 15. H. Lyallii. 
Froud rigid, erect, clothed with stellate hairs. See Trichomanes hlalingii, p. 356. 
1. H. tunbridgense, Smith; — FI. N. Z. ii. 11. Small tufted or 
matted, quite glabrous. Bhizome slender, wiry. Frond 1-3 in. high, ovate 
or linear, pinnate below, pinnatifid above; segments close or distant, long or 
short, spreading or decurved, toothed. Involucres supra-axillary, orbicular, 
compressed, their base sunk in the segments (free in var. /3), lips spinulose 
or toothed. — Hook. Sp. Fil. i. 95. 
