GROUP I
STERILE AND FERTILE FRONDS TOTALLY UNLIKE; FERTILE FRONDS NOT LEAF-LIKE IN APPEARANCE
1. SENSITIVE FERN
Onoclea sensibilis
Newfoundland to Florida, in wet meadows.
Sterile fronds.—One or two inches to three feet high, broadly triangular, deeply cut into somewhat oblong, wavy-toothed divisions, the lower ones almost reaching the midrib, the upper ones less deeply cut; stalk long.
Fertile fronds.—Quite unlike the sterile fronds and shorter, erect, rigid, contracted; pinnules rolled up into dark-green, berry-like bodies which hold the spore-cases; appearing in June or July.
This is one of our commonest ferns, growing in masses along the roadside and in wet meadows. Perfectly formed sterile fronds are found of the tiniest dimensions. Again the plant holds its own among the largest and most effective ferns. From its creeping rootstock rise the scattered fronds
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