Page:Parsons How to Know the Ferns 7th ed.djvu/70

 GROUP IV

FERTILE AND STERILE FRONDS LEAF-LIKE AND SIMILAR; SPORANGIA ON OR BENEATH A REFLEXED PORTION OF THE MARGIN

[The first clause bars out P. gracilis and P. atropurpurea, which otherwise would belong to Group IV as well as to Group III.]

Large and coarse, frond 3-branched, spreading, each branch 2-pinnate, sporangia in a continuous line beneath the reflexed margin of the frond. In dry, somewhat open places. P. 105.

Graceful and delicate, frond forked at the summit of the stem, 2-pinnate, the pinnæ springing from the upper sides of the branches, pinnules one-sided, their upper margins lobed, bearing on their undersides the short fruit-dots. In rich woods. P. 108.

Rather small, fronds 2-pinnate, hairy, fruit-dots "covered by the infolded ends of the rounded or oblong lobes." On rocks. P. 112.

Rather large, pale, delicate and sweet-scented, fronds usually 2-pinnate, fruit-dots small, each on a recurved toothlet of the pinnule, borne on an elevated, globular receptacle. In moist thickets and in upland pastures. P. 114.