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98 F E R N S OF NORTH AM E R IC A .
pmnæ fertile, the lower pinnæ uniformly sterile. Fée noticed
that among: the sporangia are great numbers of smaller ped-
icelled corpuscles, peltate, radiate, palmate, iiitestmiform, etc.,
and, as he supposed, each kind peculiar to the species, as he’
regarded the species. Sometimes what appeared to be a mass
of sporangia he found to consist wholly of these corpuscles.
In the Indian River specimen, which Mr. Faxon has
figured, these corpuscles are intestiniform, as in F é e s C.
scaiphtrahmi, and in the Corkscrew river plants they are
irregularly radiate, with rounded points, as in F é e s C. Cayennense.
The spores are spheroid-tetrahedral, smooth, and
plainly trivittate.
The generic character of Acrostickum, as understood by
Hooker, consists in the sporangia being spread over the whole
lower surface or over large portions of the surface, sometimes
both surfaces, of the frond. Hooker & Baker describe
about two hundred species. Fée divided the genus into
eighteen genera, and even Mettenius admitted five genera
as distinct.
Plate IN IW .— Acrostichum aurmm. The specimen is a small
one, and was collected at Indian River, Florida, by Dr. Edward Palmer.
Fig. 2 IS a part of a fertile pinna, enlarged, so as to show the sporangia,
which are partly removed. Fig. 3 is a spore. Fig. 4, a section
of the stalk.
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