146 CHARACTERS OF TRIBES AND GENERA. 
long, 2 to 3 inches broad, the upper pairs of pinne con- 
tracted and fertile. Veins uniform, reticulated, forming 
numerous elongated subquadrangular parallel areoles. 
Sporangia densely occupying the whole of the under surface 
of the fertile pinnæ. 
Type. Acrostichum aureum, Linn. 
lllust. Hook, and Bauer. Gen. Fil, t. 81 A.; Moore 
Ind. Fil, p. 8, B; J. Sm. Ferns, Brit. and For» 
fig. 54, 
Osns.—This genus was founded by Linneus in 1737, 
the typical species being Acrostichum aureum, but subse- 
‘quently he, and other authors, added numerous other 
species to the genus, indeed it may be said that all Ferns 
in which the sporangia were not evident in well defined 
round or linear masses were referred to this genus, as 
shown by Moore's “Index Filicum," in which no less than 
473 generic and specific names are recorded, of which 
about 140 now constitute the tribe Acrostichee : the prin- ` 
cipal are given as examples under the respective new ` ` 
genera as above defined. 2 
The genus Acrostichum, as here restricted, consists of 
only one species, namely, A. aureum, which is found in 
most Fern regions throughout the tropies of both hemi- 
spheres, which under the different influences of climate, | 
and growing in wet or dry places assumes very different 
aspects as regards size and texture, such being the case, 
has led to a dozen or more Specific names being given by 
authors to the different states. In the “Species Filicum ” 
. they are all recorded as synonyms, in which I concur. = 
—.. Bp. A. aureum, Linn, (A. marginatum, Schk., A. inequale, — — 
Willd., A. speciosum, Willd., A. danæfolium, Lang. et Fisch., SC 
A. fraxinifolium, R. Br., A. sculpturatum, Presl, A. obliquum, 
Bl., Chrysodium hirsutum, Fée.), des 
