212 CHARACTEES OP TRIBES AND GENERA. 



SERIES 2. Veins free. 

 * Sori Indusiate. 



Sect. 3. OREOPTEREJS. 

 Sori punctiform. Indusium orbicular or reniform, plane. 



111. LASTREA, Presl. (1836). 

 Poly podium sp. auct. ; Nephrodium sjp., Hook. Sp. Fit. 



Vernation uniserial, sarmentose or fasciculate, erect or 

 decumbent, acaulose, rarely sub-arboroid. Fronds varying 

 from pinnatifid to decompound multifid, 1 to 6 feet high. 

 Veins simple, or once or several times forked, or costae- 

 form and pinnate ; venules free. Receptacles punctiform, 

 terminal or lateral. Indusium reniform or sub-rotund, 

 interiorly attached. 



Type. Aspidium Filix-mas, Sw. 



Illust. Hook, and Bauer. Gen. Fil., t. 45, A. ; Hook. Brit. 

 Ferns, 1. 15 ; Hook. Fil. Exot.,t. 98 ; Moore Ind. Fil., 

 p. 71 ; J. Sm. Ferns Brit, and For., fig. 75 ; Hook. 

 Syn. Fil., t. 5, fig. 44. 



OBS. The above character embraces a large number of 

 widely distributed species, abounding within the tropics, 

 and extending to the furthest limits of Fern vegetation in 

 both hemispheres. These numerous species vary greatly 

 in the size and circumspection of their fronds, agreeing in 

 general habit with the genus Phegopteris, the want of 

 indusia in the latter being the only technical distinction, 

 that organ, however, is often very small and soon becomes 

 obliterated, and as stated under Nvphrodium, when absent, 

 the species of Lastrea are consequently placed under 

 Phegopteris. The indusium varies considerably in size and 

 texture and in the depth of the sinus, the latter being 



