D 
| 900 CHARACTERS OF TRIBES AND GENERA, 
a good deal in outline, as above noted, and varying in the 
presence or absence of the involucre, whether from being 
quickly deciduous, or, as I apprehend, its entire suppression 
at times, it is hard to say." From this view I differ, for, 
in cultivated plants of P. plantagineum, as well as in many 
herbarium specimens of the same that have come under 
my notice, I found no traces of indusium, and therefore 
consider it to be normally absent; it consequently comes 
under the genus Dryomenes while P. sinuata not only 
differs in the general outline of the frond, but also in the 
sori being furnished with a large peltate indusium, and 
as it agrees in general habit with P. Singaporiana, I 
therefore associate it with that species. 
104, Aerm, Sw., in part (1800). 
Hook., Sp. Fil. 
Vernation fasciculate, erect. Fronds trilobed, pinnate, 
bipinnatifid or bipinnate, 1 to 4 feet high, ultimate segments 
generally broad and flaccid. Primary veins costeform, 
venules simply or compoundly anastomosing. | Receptacles 
compital or often on the apex of free veinlets, terminating 
in the areoles. Soriround. Indusiwm orbicular or reniform. 
Type. Aspidium trifoliatum, Sw. 
Illust. Schott., Gen. Fil., t. 4; Hook. and Bauer, Gen. 
Fil, p. 33; Moore, Ind. Fil., p. 65, B; J. Sm., Ferns, 
Brit. and For., fig. 70; Hook., Syn. Fil., t. 5, fig. 43, d. 
- Oss.—This genus consists of between twenty and thirty’ . 
species of strong-growing Ferns, generally with mem. ` 
 braneous flaccid fronds. They are widely distributed 
throughout the West Indies, Tropical America, West 
Africa, Mauritius, Ceylon, India, Malayan, Philippine, and 
Polynesian Islands. 
