CHAEACTERS OF TRIBES AND GENERA. 257 



Illust. Hook, and Bauer, t. 44, A ; Moore Ind. Fil., p. 83, 

 B ; J. Sm. Ferns, Brit, and For., fig. 129 ; Hook. Syn. 

 Fil., t. 1, fig. 3. 



OBS. This genus is found on a solitary species, a native 

 of Juan Fernandez ; it is said to have a slender arborescent 

 stem, which seems to be correct, as shown by imported 

 plants cultivated at Kew. 



In the " Species Filicum " Thyrsopteris is placed in the 

 tribe Cyathea, but its terminal marginal sori, and general 

 habit, clearly indicates its relationship to be with Dicksonia. 

 It agrees with the following genus, Balantium, in having 

 decompound fronds, differing only in the fertile segments 

 being contracted into pedicels, each bearing a globose 

 sorus, forming panicles, hence the name Panicularia given 

 to the genus by Colla in 1836. 



Sp. T. elegans, Kze. (v v.) (SM. Fil. Suppl.,p. 3, t. 1.) 



139. BALANTIUM, Kaulf. (1824.) 

 Dicksonia, Hook. Sp. Fil. 



Vernation fasciculate, decumbent, densely criniferous. 

 Fronds deltoid, tripinnate, smooth ; ultimate pinnules 

 dentate, multifid. Feins pinnate, venules free, simple or 

 forked. Receptacles punctiform, terminal. Sori large, 

 transversely oblong, exserted in thryseform clusters. I?- 

 dusium bivalved, coriaceous, the two valves nearly equal, 

 concave, reniform. 



Type. Dicksonia Culcita, L'Herit. 



Illust. Hook, and Bauer. Gen. Fil., t. 60 A. ; J. Sm. 

 Ferns, Brit, and For., fig. 126. 



OBS. The technical character of this genus differs but 

 little from Thyrsopteris, but is distinguished by the caudex 

 being decumbent. 



The typical species is a native of the Azores and Madeira, 



