﻿1. CY^^THEA-CEAJE (*). 



Sori globose or ellipsoid, dorsal or terminal on the veins; sporangia 

 numerous, sessile or stalked, furnished with a complete, oblique (subvertical) 

 ring, which is sometimes interrupted at the place of the stomium by a row 

 of depressed, transversally oblong cells; stomium opening at right angles to 

 the ring; receptacle often elevated. Indusium wanting or more generally 

 present and then scale-like, 2-valved, subcupuliform or globose, but then after- 

 wards evanishing or becoming cup-shaped, sometimes consisting of a whorl 

 of hairs or fibres, always fastened beneath the sorus. 



Caudex arborescent, sometimes subarborescent. Fronds often very large, 

 mostly compoundly divided ; veins free or the costal ones sometimes anasto- 

 mosing in Hemitelia. 



Tropical and subtropical. 



Arrangement of the tribes. 



$ 1. CYATHEAE. Sori dorsal, placed on the back or at the forking of 

 a vein. Annulus not interrupted by a row of depressed cells. 



§ 2. DICKSONIEAE. Sori terminal on the veins. Annulus interrupted 

 by a row of depressed cells at the place of the stomium. 



Key to the tribes and genera. 



Sori on the back or at the forking of a vein. CYATHEAE. 



«. Sori indusiate. 



b. Indusium distinct, globose, quite enclosing the sorus when young, 



bursting down irregularly, afterwards evanishing or becoming + 



cup-shaped. Receptacle central. No. 1. Cyathea. 



b.h. Indusium distinct, squamiform, convex, placed at the inner side of 



the receptacle. No. 2. Hemitelia. 



(*) The species of this family are difficult of determination unless the whole stipe and 

 the lowest pinnae besides the central pinna and a portion of the main rachis are present. 



