| GROUP VI | FERTILE AND STERILE FRONDS LEAF-LIKE |
way of holding itself. Sometimes the fronds stand three feet high, and are broad and spreading. Again, they are tall, slender, and somewhat erect. Again, they are not more than a foot high.
At its best it grows with almost tropical luxuriance and is a plant of rare beauty, its fronds having a certain featheriness of aspect uncommon in the Aspidiums.
Var. dilatatum (D. spinulosa dilatata)
Newfoundland to North Carolina, chiefly in the mountains.
Fronds.—Usually large, broader at base than in either of the preceding species, ovate or triangular-ovate, oftenest thrice-pinnate; pinnules lance-oblong, the lowest often much elongated; fruit-dots round; indusium smooth.
This form of the Spinulose Wood Fern is distinguished chiefly by its broader fronds and by the smooth indusia. As these indusia can be seen satisfactorily only by the aid of a magnifying-glass, there is frequently some difficulty in distinguishing this variety. Occasionally it occurs in a dwarf state, fruiting when only a few inches high.
41. BOOTT'S SHIELD FERN
Aspidium Boottii (Dryopteris Boottii)
Nova Scotia to Maryland, about ponds and in wet places. One and a half to more than three feet high, with somewhat chaffy stalks which have pale-brown scales.
Fronds.—Long lance-shaped, somewhat narrowed at base, nearly or quite twice-pinnate; pinnæ, the lowest triangular-ovate, upper longer and narrower; pinnules oblong-ovate, sharply thorny-toothed, somewhat pinnatifid below; fruit-dots round; indusium slightly glandular.
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