CHARACTERS OP TRIBES AND GENERA. 277 



154. HEWARDIA, J. 8m. (1840). 

 Adiantum, sp. t Hook. Sp. Fil. 



Vernation sarmentose (?) Fronds 1 to 2 feet high, pin- 

 nate, or dichotomously bipinnate, smooth, pinnae and 

 pinnules alternate, distant, petiolate (not articulate), some- 

 times falcate, 4 to 8 inches long, 1 to 2 inches wide. 

 Costce evident, central. Feins uniform, reticulated, forming 

 elongated, oblique areoles. Indusium marginal, continuous, 

 venose, and sporangiferous on its under side, as in Adian- 

 tum, at length becoming replicate and involute, forming a 

 continuous sorus, occupying both margins. 



Type. Hewardia adiantoides, J. Sin. 



Illust. Hook, and Bauer, Gen. Fil., t. 89 ; Moore, Ind. 

 Fil., p. 25 A. 



OBS. This genus is distinguished from Adiantum by 

 having reticulate venation, on both sides of the central costas. 



Sp. H. adiantoides, J. Sm., Hook. Journ. Bot., vol. 3, 

 t. 16 and 17 ; H. dolosa, Fee, Hook. Sp. Fil., 1, t. 79 B. 



Natives of Guiana and Brazil. Although the latter 

 species agrees in general habit with H. adiantoides, the 

 veins, however, are not so decidedly anastomose, and on 

 account of H. Wilsoni and A. Leprieurii having occasional 

 anastomose venation, they are therefore by some also re- 

 ferred to this genus. 



Tribe 20. CHEILANTHEJ3. (Plate 20.) 

 Fronde varying from simple pinnate to decompound 

 multifid, and from a few inches to 2 feet in height, smooth, 

 or densely tomentose or squamose. Venules free. Sporan- 

 gia terminal, marginal ; sori punctiform, distinct, or two 

 or more laterally confluent, seated in the axis of the in- 

 flexed membraneous margin of the segment (indusium). 



