62 



THE BOOK OF CHOICE FERNS. 



stalks 6in. to 12in. long ; they are oblong in shape and bi- or tripinnate 

 (twice or three times divided to the midrib), their leaflets varying from 

 simply pinnate to copiously bipinnate. The leafits, of a soft, papery 

 texture and yellowish-green colour, are egg-shaped when barren, except the 



terminal ones, which usually are 

 distinctly halbert-shaped and un- 

 dulated on their margins : these 

 characters are much more con- 

 spicuous when the plant is fertile 

 (Fig. 22 shows barren fronds 

 only). The fronds are smooth on 

 both surfaces, and the sori (spore 

 masses), disposed in a continuous, 

 marginal line, are provided with a 

 somewhat narrow, thin involucre, 

 nearly or quite hidden when the 

 spores are ripe. — Hooker, Species 

 Filicum, ii., p. 145 ; Filices Exoticce, 

 t. 50. Nicholson, Dictionary of 

 Fig. 22. Penza hasMa Gardening, iii, p. 67.^ Lowe, Ferns 



(much reduced). British and Exotic, iii., t. 32. 



P. (Allosorus) intramarginalis — All-os-o'-rus ; in-tra-mar-gin-a'-lis 

 (within the margin), /. Smith. 

 A delicate-looking, greenhouse species, native of Mexico and Guatemala, 

 with broadly spear-shaped fronds, 6in. to 12in. long, 2in. to 4in. broad, twice 

 divided nearly to the midrib, and borne on tufted, upright, dark chestnut-brown, 

 polished stalks 3in. to 6in. long. The spear-shaped leaflets (Fig. 23), 2in. to 

 3in. long, lin. broad, and opposite, are cut down nearly to the rachis into 

 long, narrow-oblong leafits, of a somewhat leathery texture, pale or glaucous 

 green in colour, and smooth on both surfaces. The abundant and conspicuous 

 sori (spore masses) are disposed in a continuous, single, intramarginal row, and 

 covered by a broad, somewhat fringed, thin and transparent involucre. — Hooker, 

 Species Filicum, ii., p. 112. Nicholson, Dictionary of Gardening, iii., p. 67. 

 Lowe, Ferns British and Exotic, iii., t. 31. 



