Part 31

a Portion of fertile pinna b Tip of pinna showing veining]

38. MARSH FERN

Aspidium Thelypteris (Dryopteris Thelypteris)

New Brunswick to Florida, in wet woods and swamps. One to nearly three feet high.

Fronds.--Lance-shaped, slightly downy, once-pinnate, fertile fronds longer-stalked than the sterile; pinnæ, the lower ones hardly smaller than the others, cut into oblong, entire lobes, which are obtuse in the sterile fronds, but appear acute in the fertile ones from the strongly revolute margins; veins once or twice forked; fruit-dots small, round, half-way between midvein and margin, or nearer margin, soon confluent; indusium small.

In our wet woods and open swamps, and occasionally in dry pastures, the erect, fresh-green fronds of the Marsh Fern grow abundantly. The lowest pinnæ are set so high on the long slender stem as to give the fern the appearance of trying to keep dry, daintily holding its skirts out of the mud as it were.

The plant's range is wide. As I pick my way through marshy inland woods, using as bridges the fallen trunks and interlacing roots of trees, its bright fronds standing nearly three feet high, crowd about me. Close by, securing, like myself, a firmer foothold by the aid of the trees' roots, I notice the flat, mottled green and white rosettes and the slender wands of flowers of the rattlesnake orchid. In the open swamps beyond the fern's companion is another orchid, the ladies' tresses, with braided spikes of white, and in this case deliciously fragrant flowers.

In open marshes near the sea I find this plant associating itself with the violet-scented adder's mouth, with glistening sundew, and with gaudy Turk's-cap lilies.

From the New York Fern it may be distinguished easily by the somewhat abrupt instead of tapering base of the frond, by the strongly revolute margins of the fertile frond, and by its long stalk.

MARSH FERN

Fertile frond Sterile frond]

From the Massachusetts Fern it may be distinguished by its forked veins, the less revolute margins of the fertile frond, and by its thicker texture and deeper green.

39. MASSACHUSETTS FERN

Aspidium simulatum (Dryopteris simulata)

New Hampshire to the Indian Territory, in wooded swamps. One to more than three feet high.

Fronds.--Oblong-lance-shaped, little or not at all narrowed at the base, rather thin, pinnate; pinnæ lance-shaped, cut into oblong, obtuse segments, which are slightly reflexed in the fertile fronds, veins not forked; fruit-dots rather large, somewhat distant; indusium "withering-persistent."

This species closely resembles the Marsh Fern. The less revolute margins of the fertile frond, the simple veins, its thinner texture, and its more distant fruit-dots aid in its identification. It is found in woodland swamps from New Hampshire to the Indian Territory.

SPINULOSE WOOD FERN

Aspidium spinulosum, var. intermedium

a Portion of fertile pinnule]

40. SPINULOSE WOOD FERN

Aspidium spinulosum (Dryopteris spinulosa)

Newfoundland to Kentucky. The common European type, rare in North America. One to two and a half feet high, with stalks having a few pale-brown deciduous scales.

Fronds.--Lance-ovate, twice-pinnate; pinnæ oblique to the rachis, elongated-triangular, the lower ones broadly triangular; pinnules oblique to the midrib, connected by a narrow wing, cut into thorny-toothed segments; fruit-dots round; indusium smooth, without marginal glands, soon withering.

To my knowledge I have only seen this fern in the herbarium, it being rare in this country. It is found, I have been told, chiefly toward the tops of mountains. Its pinnæ are noticeably ascending.

Var. intermedium (D. spinulosa intermedia)

Labrador to North Carolina, in woods almost everywhere. Usually large, with somewhat chaffy stalks, having brown, dark-centred scales.

Fronds.--Oblong-ovate, 2-3 pinnate; pinnæ oblong-lance-shaped, spreading, rather distant, the lowest unequally triangular, the pinnules on the lower side longer than those on the upper side; pinnules ovate-oblong, spreading, with oblong lobes thorny-toothed at the apex; fruit-dots round; indusium delicate, beset with tiny stalked glands.