OS 



THE BOOK OF CHOICE FERNS. 



they are of a somewhat leathery texture, and their sori (spore masses) are 

 covered by an incurved involucre of a thin, transparent nature. — Hooker, 

 Species Filicum, h\, p. 132, t. 114b. 



P. (Allosorus) pulchella — All-os-o'-rus ; pul-chel'-la (pretty), Fee. 



A remarkably pretty, greenhouse species, found in Western Texas, in 

 New Mexico, and from Mexico to Peru. Regarding its habitat, Eaton, in his 

 exhaustive work on "Ferns of North America" (i., p. 81), says: "It probably 

 grows in clefts of exposed rocks, but none of the collectors seems to have 

 made a note of the kind of place where it is found." Its very elegant, oblong- 

 fronds, Sin. to 6in. long, lin. to 3in. broad, and tripinnate (three times divided 

 to the midrib), are produced from a very short, rather stout rootstock, nearly 

 erect, and borne on densely-tufted, wiry, erect stalks 2in. to 3in. long, of 

 a dark chestnut-brown colour and polished nature, except at the base, where 

 they are chaffy with narrow, crisped, nearly black scales. The lower leaflets 

 are broadly triangular, and their spear-shaped pinnules (leafits) are again 

 divided into oblong, blunt segments scarcely more than fin. long and half as 

 broad. The fronds are of a leathery texture, pale green and smooth on both 

 surfaces, with the edges of the fertile segments much enrolled, and a broad 

 involucre of a thin, papery texture, permanently rolled over the spore masses. 

 — Hooker, Species Filicum, ii., p. 150. Nicholson, Dictionary of Gardening, 

 iii., p. 67. Eaton, Ferns of North America, i., t. 11. 



P. (Cheiloplecton) rigida— Cheil-op-lec'-ton ; rig'-id-a (stiff), Hooker. 



This stove species, of medium dimensions and upright habit, is a native 

 of Mexico, Guatemala, and Peru. Its fronds, in the shape of the Greek 

 delta, A, and twice or three times divided to the midrib, are 4in. to 9in. long, 

 oin. to 6in. broad, and borne on stout, erect, naked or slightly scaly, dark 

 chestnut-brown stalks 4in. to 6in. long. The lowest leaflets, which are the 

 largest, are 3in. to 4in. long, upright, and broadly triangular ; the leafits on 

 their lower side are larger than the others and divided again into narrow - 

 oblong, blunt segments of a somewhat leathery texture and either naked or 

 sometimes slightly hairy on both surfaces. The sori (spore masses), disposed 

 in a continuous, marginal line, are covered by a broad, pale, wrinkled involucre, 

 which is rolled down tightly over them. — Hooker, Species Filicum, ii., p. 144. 



