Very small. Sterile fronds linear, grass-like. Fertile fronds taller, with a terminal fruit-cluster. In pine barrens of New Jersey. P. [63].
GROUP II
FERTILE FRONDS PARTIALLY LEAF-LIKE, THE FERTILE PORTION UNLIKE THE REST OF THE FROND
[The species coming under the genera Botrychium and Ophioglossum may appear to belong to Group I, as the fertile and the sterile portions of their fronds may seem to the uninitiated like separate fronds, but in reality they belong to the one frond.]
5. ROYAL FERN
Osmunda regalis
Large. Sterile fronds twice-pinnate, pinnules oblong. Fertile fronds leaf-like below, sporangia in clusters at their summits. In wet places. P. [67].
6. INTERRUPTED FERN
Osmunda Claytoniana
Large. Sterile fronds once-pinnate, pinnæ pinnatifid. Fertile fronds leaf-like above and below, contracted in the middle with brown fruit-clusters. In wet places. P. [72].