Above the black leaf-mould in our rocky northern woods rise the firm, graceful crowns formed by the blue-green fronds of the Evergreen Wood Fern. The plant bears a family likeness to the Crested Shield Fern, but its conspicuously marginal fruit-dots identify it at sight.
It is interesting to read that it comes "nearer being a tree-fern than any other of our species, the caudex covered by the bases of fronds of previous seasons, sometimes resting on bare rocks for four or five inches without roots or fronds" (see Eaton, p. 70). This peculiarity in the plant's growth is often striking and certainly suggests the tree-ferns of the green-house.
Frequently in this species I notice what is more or less common to nearly all ferns, the exquisite contrast in the different shades of green worn by the younger and older fronds and the charming effect produced when the deep green of the centre of a frond shades away in the most delicate manner toward its apex and the tips of its pinnules.
As its English title signifies, the Evergreen Wood Fern flourishes throughout the winter. In one of the October entries in his journal, Thoreau records his satisfaction in the endurance of the hardy ferns:
"Now they are conspicuous amid the withered leaves. You are inclined to approach and raise each frond in succession, moist, trembling, fragile greenness. They linger thus in all moist, clammy swamps under the bare maples and grapevines and witch hazels, and about each trickling spring that is half choked with fallen leaves. What means this persistent vitality? Why were these spared when the brakes and osmundas were stricken down? They stay as if to keep up the spirits of the cold-blooded frogs which have not yet gone into the mud, that the summer may die with decent and graceful moderation. Is not the water of the spring improved by their presence? They fall back and droop here and there like the plumes of departing summer, of the departing year. Even in them I feel an argument for immortality. Death is so far from being universal. The same destroyer does not destroy all. How valuable they are, with the lycopodiums, for cheerfulness. Greenness at the end of the year, after the fall of the leaf, a hale old age. To my eye they are tall and noble as palm-groves, and always some forest nobleness seems to have its haunt under their umbrage. All that was immortal in the swamp herbage seems here crowded into smaller compass, the concentrated greenness of the swamp. How dear they must be to the chickadee and the rabbit! the cool, slowly retreating rear-guard of the swamp army."
46. FRAGRANT SHIELD FERN
Aspidium fragrans (Dryopteris fragrans)
Northern New England to Wisconsin and northward, on rocks. Five to sixteen inches long, with very chaffy stalks having brown, glossy scales.
Fronds.—Lance-shaped, tapering to a point, nearly twice-pinnate, fragrant; pinnæ oblong-lanceolate, pinnatifid; fruit-dots round, large; indusium large and thin.