364 CHARACTERS OF TRIBES AND GENERA. 
fronds). Fronds bi-tripinnate, 6 to 8 or more feet high; pinnæ 
and pinnules articulated with the rachis. Veins simple or 
forked, free. Sporangia sub-terminal, connate, forming a 
bivalved synangium, each valve consisting of 3 to 12 cells, 
opening by slits. Receptacles ovate, oblong, some species 
furnished with an indusoid fimbriate membrane. 
Type. Marattia alata, Sm. 
 lilust. Hook. and Bauer Gen. Fil, t. 26; Moore Ind. 
Fil, p. 96 B.; J. Sm. Ferns, Brit. and For., fig. 150; 
Hook. Syn. Fil., t. 9, fig. 70. 
Oss.—The general habit and mode of development of 
the fronds of this genus does not differ from Angiopteris, it 
is, however, readily distinguished by its sporangia being 
wholly: united, the two series forming a double multilocular 
spore case, which, when mature, opens lengthways in two - 
lobes (valves), each lobe containing a series of cells equiva- 
lent to the sporangia of Angiopteris. Marattia is sparingly ` 
represented in India, but it is common to the Islands of the 
Indian and Pacific Oceans, extending to Norfolk Island and 
New Zealand in the South, it is also found in South Africa, 
Tropical America, the West Indian Islands, and is one of | 
the few plants forming the indigenous flora of the Island ` ` 
of Ascension. 
Presl enumerates twenty species, which he places under | 
four distinct genera, but I find no sufficient character ue o 
warrant their adoption, his species are also fully double in. vm 
excess. In the “Species Filicum " only seven species are- — 
described, and the following, which have all been cultivated 
at Kew, appear to me to have sufficient character to be 
considered distinct species. Different fronds, or even dif- 
ferent parts of the frond of the same plant when separate, 
and placed in the herbarium, have been accepted as at- 
least four distinct species. ; vobi e 
