124 CHARACTERS OF TRIBES AND GENERA. 
< Sp. P. alcicorne (Sw.) (v v.) ; P. Stemmaria ( Desv.) (v v.) ` 
(P. Aithiopicum, Hook. Gard. Ferns, t. 9); P. grande — 
(J. Sm.), Hook. Fil. Beat. t. 86; Bedd. F. Brit. Ind., pl. 
326; P. biforme (Bl. Fil, Sect t. 18) (v v.); Bedd. F. 
Brit, Ind., pl. 109 ; P. Wallichii (Hook. Fil. Beat, t. 97), 
(v v.); Bedd. F. Brit. Ind., pl. 108.* 
Ons.— In Queensland P. grande grows to a large size on 
trees. The barren fronds overlapping each other, and 
forming a round or oblong convex mass, 2 to 3 feet in 
diameter, and as much high ; which often becomes so sur- 
charged with water, that the whole mass in time falls to i 
the ground. 
Drviston II.—DESMOBRYA. 
Vernation terminal, adherent, uniserial, or fasciculate. 
I. Ring of Sporangia vertical. 
Tribe 6.—ACROSTICHEAÆ (Plate 6). 
| Fronds dimorphous, the fertile wholly or some portion of ; 
it contracted. Veins obscure. Sori amorphous. 
. Oss.— This tribe is composed of species of the genus ` 
Aerostichum, of Linnsus, Swartz, and other authors, as . 
. now restricted, the number of described species being about à 
. 140t They vary greatly in size and in the circumscription 
.. of their fronds, which, with the difference of their vernation - 
. and venation, afford sufficient characters to admit of the 
` "fa the Gardeners’ Chronicle, March 6th, 1875, Mr. T. Moore 
. described a new species under the name of P. H: illinickii, a native of. 
. Java. Its fructification is terminal, on narrow MEN. like thata 
EE aleicorne. 
` in the Appendix to “Syn. Fil.” forty additional species e 
