FERNS 451 



trichomanes}. 2 to 6 inches. Stalk slender, hairlike, black. Ovate pinnae. 

 Abundant on shaded rocks, old walls, and buildings. 



16. Common Hart's Tongue (Scolopendrium vulgar e). Fronds 6 to 18 inches ; 

 oblong, strap-shaped, simple. Sori at short intervals on upper portion. 

 Common on shady banks and rock clefts. 



17. Hard Fern (Blechnum spicant). Fronds simple, pinnate, tufted. 

 Fertile 12 to 18 inches, with narrow acute segments. Under side covered with 

 son. Barren fronds deeply pinnatifid. Found in moist boggy land, and heaths 

 and woods. 



18. Brakes, or BRACKEN (EAGLE FERN) (Pteris aquilina). Very common, 

 sometimes attaining a height of 6 to 10 feet. Continuous lines of sori on the 

 margins. Fronds compound bipinnate. 



19. True Maidenhair (Adiantium capillus-veneris) . The only British 

 species, recognized by its fan-shaped leaflets and wiry black stalks. 9 to 15 

 inches. Very local in Cornwall and Devon. 



20. Brittle Bladder Fern (Cystopteris fragilis). Fronds 5 to 6 inches, 

 growing in tufts. Lanceolate and bipinnate. Veining in fronds very distinct. 

 Almost every vein terminates in a group of roundish capsules, becoming con- 

 fluent as fern grows. Widely distributed ; moist mountainous districts. 



21. Tunbridge Hymenophile (FiLMY FERN) (Hymenophyllum tunbridgense). 

 The smallest of our British ferns (2 to 3 inches) ; pinnate, lanceolate; olive-brown. 

 Veins very strongly marked, the leafy part being slight and membranous. 

 Roots thread-like, matted. Found in many mountainous districts among moss. 



22. Royal or Flowering Fern (Osmunda regalis). Noted for its flowery 

 panicle, sometimes 3 to 4 feet above the other fronds. In old plants the stem 

 looks like a trunk, the leafy bipinnate fronds depending from its crown. 

 Found in marshy districts, but local. 



23. Moonwort (Botrychium lunaria). In its early stages hardly like a fern, 

 consisting of an upright simple stem, in reality a bud, enclosing a fertile and 

 barren frond. The pinnae are obliquely fan-shaped or half-moon, thick and 

 entire. Found on dry open moors ; chiefly in Staffordshire, Surrey, and 

 Yorkshire ; also Isle of Wight. Name derived from the crescent shape of the 

 pinnae. 



24. Common Adder's Tongue (Ophioglossum vulgatum). Resembling in 

 its growth the Cuckoo-pint (Arum maculatum}. 3 to 9 inches. One frond, 

 barren, enclosing an upright spike, in which are two lines of spore-cases. When 

 ripe, the spike opens, the pollen is discharged, leaving behind a double row of 

 round empty cells. Generally distributed. 



Club-mosses and Horse-tails. 



Of the Club-mosses and Horse-tails but little need be said. There are six 

 species of the former in Britain, of which the commonest is the Wolf's 

 Claw (Lycopodium clavatum). 



