194 CHARACTERS op TRIBES AND GENERA, 
98. ÅAMPHIBLESTRA, Presl. (1836). 
Pieris, sp., H. and B., Hook., Sp. Fil. 
Vernation fasciculate, erect (?). Fronds stipate, 2 to 3 
feet high, pinnate, membraneous, flaccid, pinnæ 2 to 3 pairs, 
oblong acuminate, petiolate, 8 inches or more in length, 
2 to 3 inches broad, entire or the lower ones lobed, sub- 
pinnatifid. Primary veins costeform, venules compound 
anastomosing, with free veinlets terminating in the areoles. 
Receptacles compital, contiguous, forming a linear sub- 
continuous marginal sorus, included under or near to the 
narrow inflexed membraneous indussform margin. ` 
Type. Pteris latifolia, H. and B. 
Ilust. Hook. and Bauer, Gen. Fil, t. 120, C; Moore, 
Ind. Fil., t. 83, A. Both copied from Presl. 
Oss.—This genus is founded on a remarkable and rare 
Fern, first described by Willdenow in 1810, from specimens 
collected in Venezuela by Humboldt and Bonpland. At 
the time of the publication of Hooker and Bauer's * Genera 
Filicum " I had not seen specimens of this Fern, and there- 
fore followed Presl in retaining it in Pteridee ; having 
subsequently received specimens, I find its natural asso- 
ciation to be with Dryomenes, Dictyopteris, and Aspidium, 
especially such as A. macrophyllum, with which it agrees 
in habit and venation, but differs from Aspidium in having 
the sporangia produced close to the margin, and forming 
an apparent linear sorus parallel with the margin which is 
inflexed in the form of a narrow membraneous indusium, 
which circumstance led authors to refer it to Pteris. I, how- 
ever, view this Fern as an aberrant form of the Aspidee 
alliance, 
Sp. A. latifolia, Pr., Kze. Schk., Supp. II., 43, t. 118. 
