CHAEACTERS OF TEIBES AND GENEBA, 277 



154.— Hbvvaedia, J. 8m. (1840). 

 Adianttim, sp., Hook. Sp. Fil. 



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

 nate, or diohotomously bipinnate, smooth, pinjiEB and 

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

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

 Costal evident, central. Veins uniform, reticulated, forming- 

 elongated, oblique areoles. Indusium marginal, continuous, 

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

 tum, at length becoming replicate and involute, forming a 

 contiauous sorus, occupying both margins. 



Tyj)e. Heioardia adiantoides, J. Sin, 



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

 Fil., p. 25 A. 



Obs. This g'enus is distinguished from Adiantum by 

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



Sp. H. adiantoides, /. Sni., 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 IE. adiantoides, the 

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

 account of U. JVilsoni and A. Leprieurii having occasional 

 anastomose venation, they are therefore by some also re- 

 ferred to this genus. 



Tribe 20.— CHEILANTHEiE. (Plate 20.) 

 Fronds varying from simple pinnate to decompound 

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

 or densely tomentose or squamose. Venules iree. 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). 



