A Dictionary of Choice Ferns. 
187 
CRYPTOGRAMMK— continued. 
gem also grows luxuriantly in a cold frame, or for 
two or three years in the greenhouse, or under the 
shade of vines, where, however, it seldom lasts any 
longer. The plants should always be well established 
in pots before being turned out into the border or 
on the rockery. 
C. crispa. 
The fronds are of a pale^ delicate green colour, 
abundantly produced from a densely-tufted rootstock, which 
lies horizontally just beneath the surface of the soil and 
produces a great quantity of very minute, hair-like, fibrous 
rootlets. These fronds, of a soft, papery texture and 2in. 
to Gin. long, are borne on straw-coloured, polished stalks of 
the same length and slightly scaly towards the base ; they 
are oblong in shape, three or four times divided half-way 
to the midrib, and naked on both surfaces. In the barren 
fronds, the ultimate segments are somewhat wedge-shaped 
and deeply pinnatifid, while those of the fertile fronds are 
pod-shaped. The sori are hidden beneath the reflexed 
margins of the segments, which nearly join at the midrib, 
eventually becoming confluent. This is Allosorus crispus of 
the older botanists. 
C, c. acrosticiioicles 
This variety is a native of North America, where it is 
commonly known under the popular name of American 
Rock-Brake. It is of larger and stronger habit than our 
species, the barren fronds having their rachis narrowly 
winged, and their segments of thicker texture and not so 
deeply cut. The fertile fronds are twice as long as the 
others, and are provided with fewer and more distant, 
longer, narrow and distinctly-stalked segments ; these are 
pod-like, and their edges are so far recurved as to meet at 
the midvein or even to overlap, forming a papery involucre 
which spreads when mature. 
CYATHEA. 
About eighty species are embraced in this 
genus (which includes Disjjhenia), but few are in 
cultivation even in large establishments. Still, like 
the closely-allied Alsophilas and Dicksonias, the 
majority of these species are highly decorative, and 
several are deservedly popular and extensively 
used for the embellishment of our conservatories 
and winter gardens. Indeed, it may be truth- 
