I- OY^THEACEA^E. 



Key to the tribes and genera. (Modified). 



a. Sori not terminal on the veins. § 1. CYATHEAE ('). 



b. Sori with an indusiuhi. 



c. Indusium distinct, globose, quite enclosing the sorus when 

 young, at length bursting down irregularly, evanishing or 

 becoming more or less cup-shaped. No. 1. Cyathea. 



C.C. Indusium distinct or indistinct, not globose. 



d. Indusium consisting of a more or less conves, not rarely 



rudimentary, scale placed at the inner side of the 



receptacle. No. 2. Ileuiitelia. 



d.d. Indusium consisting of a minute orbicular scale encircling 



the receptacle. No. 3. Alsophila. 



6.6. Sori without an indusium. No. 3. Alsophila. 



«.a. Sori terminal on the veins. § 2. DICKSONIAE. 



•{• Indusium 2-valved, the outer valve consisting of an unmodified 



cucuUate lobe of the frond, forming with the inner valve a 



saccate involucre to the sorus. 



• Ultimate segments equal-sided at the base. 



No. 4. fllicksonia. 



• • Ultimate segments more or less distinctly unequal-sided at the 



base, produced on the anterior side. No. 4a. Balantium. 



f •{• Indusium 2-valved, the outer valve like the inner one, distinctly 



differentiated from the margin of the frond, l3oth forming a 



saccate involucre to the sorus. No. 5. Cibotiiiin. 



1. CYA.THEA, Smith. 



{la) C. arthropoila, Copel., in Philipp. Journ., VF, 184, tab. XlII. 



Stipes ± 40 cm. long, smooth, naked, clothed at the base with ferrugi- 



neous scales. Fronds simply pinnate, 50 — 60 cm. long, 20 — 25 cm. broad. 



(') Perhaps in the whole range of the great family of ferns'' there is not a group 

 more difticult of accurate determination than are the species of the section Eucyathea 

 of Cyathea (Hk.). — The same may be said of the whole tribe of Cyatheae. 



