Filices.] FLORA OF TASMANIA. 133 
DisrRis. New South Wales. 
A very different plant in habit from D. Antarctica, and appearing to belong to a different genus, but there 
are numerous ìntermediate species in various tropical countries.—Pronds 2-5 feet high, rather coriaceous, pale, 
arising from a stout, creeping rhizome, tripinnate. Pina deeply divided; pinnules obliguely oblong-lanceolate, 
pinnatifid. Sori near the apices of the lobules; upper valve of the involucre formed of the coriaceous recurved 
lobule of the frond; lower small and membranous. 
Tribe III. HYMENOPRYLLEE.—Sorus at or beyond the edge of the frond. Capsules sessile, on a filiform or 
club-shaped, often elongated receptacle, girt with an oblique ring. Frond very delicate, transparent, 
and reticulated. 
Gen. IV. HYMENOPHYLLUM, Sm. 
Sori marginales. Capsule receptaculo cylindraceo fronde immerso v. exserto subsessiles, depresse, 
annulo completo transverse cincte, longitudinaliter rupte. Jmvolucrwm textura frondis, bivalve, urceo- 
latum v. compressum ; valvis planis v. convexis, extus liberis.—Frondes membranacez, pellucida, cellulis 
magnis reticulate, costa valida percursa. 
One of the largest and most; beautiful genera of Ferns, generally of small size, easily recognized (except from 
Trichomanes) by the transparent pellucid texture of the delicate green, glistening fronds, which are beautifully reti- 
culated when seen through the microscope.—hizome slender or stout, wiry, filiform, creeping. Fronds generally 
glabrous, often flaccid, pinnately or pinnatifidly divided into linear, blunt, dichotomously branched segments, through 
which runs a stout midrib. Sori at the axils or ends of the segments, sunk in the substance of the frond, which 
forms a cup-shaped or box-like, often flattened, two-valved involucre over them. Sometimes the involucre is pro- 
duced beyond the frond, and stalked ; its two valves or lips are entire or toothed, and open outwards. Capsules 
sessile, on a filiform or cylindrical receptacle, that is sometimes exserted, like a thread, beyond the involucre, 
sessile, depressed, surrounded with a complete ring, and bursting longitudinally. (Name from Ze, a membrane, and 
dvo», a leaf.) 
$ A. Fronds quite glabrous ; margins toothed or serrate, not ciliate. 
1. Hymenophyllum Tunbridgense (Sm. Fl. Brit.), var. 8. cupressiforme; fronde elongata erecta 
rigida, pinnis distantibus decurvis, segmentis angustissimis, involucris lobulo frondis quasi stipitatis liberis. 
— Hook. Sp. Fil. i. p. 95; Fl. N. Zeal. ii. 11; Br. Prodr. 159. H. cupressiforme, Lab. Fl. Nov. Holl. 
p. 102. 4. 950. f. 2. H. revolutum, Col. in Tasm. Phil. Journ. (Gunn, 46, 1510.) 
Has. Abundant in shady places, on the ground, and on rotten trunks of trees.—(v. v.) (Cultivated 
in England.) 
Disteıs. Victoria, New Zealand, South Chili, Fuegia, and Brazil, South Africa. 
The H. Tunbridgense is a scarce English Fern, and a great favourite with cultivators. The Tasmanian state 
of the species has a narrower and more decumbent frond, often remarkably curved downwards on to the ground, 
and narrower segments.—Fronds 2-4 inches high, ovate or linear, pinnate below, pinnatifid (rachis winged) above, 
quite glabrous. Pinne very narrow, distant, rigid; segments long or short, spreading or curved downward, deeply 
and sharply toothed. Znvolucre orbicular, compressed at the axils of the segments, erect, projecting beyond the 
frond, in which their bases are sunk, their lips spinulose or irregularly toothed, rarely nearly entire. The ordinary 
state of H. Tunbridgense, with short, broad, oblong, flat, bright-green fronds, with broad, short pinne and seg- 
ments, and involueres more sunk in the segments, is a different-looking Fern from its deep-green, sparingly 
branched var. B, and also from H. unilaterale, but these characters vary in whatever parts of the world they both 
inhabit, and the ß. eupressiforme seems all but intermediate. 
2. Hymenophyllum unilaterale (Willd. Sp. Pl. v. p. 521); frondibus czespitosis n s 
M 
VOL. II. 
