CHARACTERS OF TRIBES AND GENERA. 985 
160.—Pzrnxa, Link. (1841). 
Hook. Sp. Fil. ; Pteris, Cheilanthus and Allosorus sp. auct. 
Vernation fasciculate, erect or decumbent, acaulose. 
Fronds deltoid lobed, pinnate or bi-tripinnate, one to two 
or more feet in height, smooth, castaneous or glaucons, 
pinnules articulate with the rachis, or to a short adherent 
petiole. Veins forked; venules free. Receptacles terminal, 
the sporangia becoming laterally confluent, forming a con- 
tinuous transverse marginal sorus, included under a reflexed 
membraneous indusium. 
Type. Pteris hastata, Sw. 
Ilust. Hook. and Bauer Gen. Fil, t. 5; Hook. Fil. 
Exot., t. 15 ; J. Sm. Ferns, Brit. and For., fig. 91. 
Oss.—This genus as here restricted consists of about 
twenty or thirty species, which are widely spread over the 
tropies and sub-tropical regions of both hemispheres, with 
the exception of P. geraniefolia; the species of the Eastern 
and Western hemispheres are respectively distinct. 
At page 278 I have stated that it is more on account of 
habit and texture that has induced me to place this genus 
under Cheilanthec, than under the tribe Pteridee. In some 
. Species originally placed under Pella, the sporangia occupy 
a portion of the upper part of the venules, forming short 
linear sori, in such cases the apices of venules being free 
and not connected in a transverse receptacle as in true 
_ Pteris; consequently the inflexed margin cannot be viewed 
otherwise than as an universal indusium analogous to 
Allosorus. . 
* SPECIES oF THE EASTERN HEMISPHERE. 
Bp: P. geranicefolia, Fée (v v.); P. Tamburii, Hook.; P. 
. auriculata, Link. ; P. deltoidea, Baker; P. Doniana, Hook. ; 
` P. hastata, Link. (v v.); P. Boivini, Hook; P. consobrina, 
