74 



THE BOOK OF CHOICE FERNS. 



black colour and quite smooth. Their leafletB, lin. to liin. long, 4in. to oin. 

 broad, are sessile (stalkless) or nearly so, oblong, and cut nearly to the rachis 

 (stalk of the leafy portion). The abundant sori (spore masses) are placed 

 midway between the midvein and the margin, and are covered by thin, 

 parchment-like, persistent involucres, which soon break down and generally 

 open at the back, so as to form a large, loose, almost transparent, two-lobed, 

 often irregularly-lacerated cup. — Hooker^ Synopsis Filicum, p. 26. 



C. angolensis — an-go'-len-sis (from Angola), Welwitsch. 



A greenhouse species, native of Benguilla, District of Huilla, Tropical 

 West Africa, where it is reported to occur at altitudes varying between 

 3500ft. and 5500ft. It is said to be rare in its native habitat and to have 

 fronds 6ft. to 8ft. long, produced from a trunk which attains 12ft. to 15ft. in 

 height and about 2ft. in circumference. This species is doubtfully distinct 

 from the better-known C. Dregei, which, however, is usually of shorter 

 stature. — Hooker, Synopsis Filicum, p. 22. 



C. arachnoidea — ar-ach-no-i'-cle-a (cobwebby), Hooker. 



A distinct, greenhouse species, native of the Island of Ternate, and 

 of very peculiar appearance through all its dark-coloured rachises (stalks of 

 the leafy portion of the fronds) being muricated (rough with short, black, 

 sharp spines) and densely clothed with a rusty tomentum. Its fronds are 

 tripinnate (three times divided to the midrib), of a firm, leathery texture, 

 smooth and shiny above, and cobwebby beneath. The sori (spore masses) are 

 disposed near the middle of the pinnules (leafits) and occupy the whole space 

 between the midrib and the recurved margin ; the involucres, of a tliin, 

 parchment-like texture, are white and delicate, and break into variously -lobed 

 and laciniated segments. — Hooker, Synopsis Filicum, p. 24. 



C. arborea — ar-bor'-e-a (arborescent), /. Smith. 



A stove species, also known as C. Grevilleana, native of the West Indian 

 Islands and most abundant in Jamaica. It is very variable in general 

 appearance, its trunk and stalks being sometimes quite smooth, but at other 

 times copiously prickly and very strongly so at the base of the stalks : this 

 species is also equally variable as regards the colour of its stalks, which are 



