36 ENGLISH BOTANY. 



Rather local, but widely distributed. Chiefly in the west of England 

 and Scotland, Cornwall, Devon, Somerset, Sussex, West Kent, Gla- 

 morgan, Merioneth, Carnarvon, Yorkshire, the Lake district, North- 

 umberland, Dumfries, Peebles, Stirling, Dumbarton, Renfrew, Argyle, 

 Bute, Arran and Mull. In Ireland it is local, being rare in the east, 

 centre and north of the island ; it occurs in Kerry, Cork, Waterford, 

 Tipperary, Kilkenny, Limerick, Clare, Longford, Galway, Sligo, 

 Leitrim, Donegal, Tyrone and Down. 



England, Scotland, Ireland. Perennial. Summer, Autumn. 



Plant growing in sheets or mats, with the black hair-like rootstocks 

 interlaced ; these are much branched, and emit numerous hairy 

 rootlets, which attach themselves to the rock or substance on which 

 the plant grows ; they are nearly naked, having a few brown hair- 

 like scales on their younger portions, and commonly a small tuft at 

 the base of the young fronds Stipes setaceous, a little thickened 

 upwards, J to 2 inches long ; lamina J to 4J inches long, by \ to 

 1 inch broad ; lower pinnae somewhat flabellately pinnatifid or pinnati- 

 partite, which arises from the distribution of the veins ; the main vein 

 of each pinna gives off a lateral vein first on the anterior side, then 

 on the posterior, then another anterior branch, and often a posterior 

 following it ; each of these branches is commonly forked, or sometimes 

 twice forked, and so is the termination of the main vein ; the ultimate 

 veins do not quite reach the apex of the ultimate divisions ; in the 

 uppermost segments the veins frequently branch only on the upper 

 side. Involucres about -^ inch long, inversely deltoid at the base, 

 which is somewhat swollen ; the valves are flattened horizontally, 

 and project beyond the substance of the leaf. The sporangia are 

 wholly included, and the vein or receptacle on which they are placed 

 does not extend beyond them. 



The leaves in texture, and in the shape of their ultimate divisions, 

 bear considerable resemblance to those of the barren stems of the 

 moss, Mnium undulatum, Hedwig. 



Tunbridge Filmy Fern. 



SPECIES II.— HYMENOPHYLLUM UNILATERALE. Bory. 



Plate 1841. 



Babenh. Crypt. Vase. Europ. Exsicc. No. 120. 



H. Wilsoni, Hook. Wilson, Eng. Bot. Supp. No. 2686. Bab. Man. Brit. Bot. ed. vii. 



p. 454. Fries, Summ. Veg. Scand. pp. 83, 253. 

 H. peltatum, Desvaux, Ann. Linn. 1827, p. 333. Babenh. I.e. 

 H. Tunbridgense, var. Bentham, Handb. Brit. Fl. p. 638. Baker in Hook. & Bah. Syn. 



Filic. ed. ii. p. 67. 

 Triehomanes peltatum, Poiret, Enc. Bot. Vol. VIII. p. 76, fide Desvaux. 



