60 THE BOOK OF CHOICE FERNS. 



oblong segments. They are of a soft, papery texture and bright green colour, 

 and their sori (spore masses), of a reddish-brown colour, are disposed in broad, 

 continuous, marginal lines and covered by a narrow indusium. — Hooker, 

 Species Filicum, ii., p. 132 ; Icones Plantarum, t. 915. Nicholson, Dictionary 

 of Gardening, iii., p. 66. Lowe, Ferns British and Exotic, iii., t. 27. 



P. (AUosorus) glauca — All-os-o'-rus ; glau'-ca (bluish - green), 

 /. Smith. 

 A stove species, of small dimensions, native of Chili and Mexico, with 

 fronds Sin. to 4in. each way, deltoid and quadripinnatifid (in form of the 

 Greek delta. A, and four times divided nearly to the midrib), borne on strong, 

 erect, polished stalks 4in. to Sin. long and of a dark chestnut-brown colour. 

 The lowest leaflets are much the largest, and the leafits on the lower side are 

 also larger than the others ; all the leafits are cut down to the rachis into 

 segments, and these are again cut down to the rachis below, the ultimate 

 divisions being about ^in. long, narrow -oblong, with inrolled edges more or 

 less notched. The fronds are of a leathery texture, naked on the upper 

 surface, and woolly underneath ; the leathery involucre is rolled down over 

 the spore masses. — Hooker, Species Filicum, ii., p. 153. 



P. GlaziOYii — Glaz-i-o'-vi-i (Glaziou's). Synonymous with P. microphylla. 



P. (Cheiloplecton) gracilis — Cheil-op-lec'-ton ; grac'-il-is (slender). 

 Hooker. 

 Although found also in Siberia, Thibet, and Northern India, where it is 

 said to occur at 9000ft. to 10,000ft. elevation, this pretty, delicate, greenhouse 

 species is a thorough North American Fern. Eaton states that it is found 

 growing in crevices of damp and shaded, calcareous rocks, especially in deep 

 glens from Labrador to British Columbia, and southward to Iowa, Wisconsin, 

 and Pennsylvania ; also in Colorado, near Breckinridge City ; and adds that, 

 though by no means a common plant, it is found in Sunderland, Massachusetts ; 

 at Trenton Falls, Chittenango Falls, and other deep glens in Central New 

 York ; in Lycoming and Sullivan Counties, Pennsylvania ; and in other 

 similar places in Vermont, Michigan, &c. The plant, which Eaton says is the 

 most delicate of all the North American Pellseas, has somewhat the general 

 appearance of Cryptogramme crispa, and is also known in gardens as P. Stelleri. 



