2. O. Struthiópteris, Hoffmann. ([Pl. 16], fig. 1–5.) Fronds growing in a crown; sterile ones short-stalked (2–10° high), broadly lanceolate, narrowed toward the base, pinnate with many linear-lanceolate, pinnatifid pinnæ; veins free, the veinlets simple; fertile frond shorter, pinnate with pod-like or somewhat necklace-shaped pinnæ. (Struthiopteris Germanica, Willd.)—Alluvial soil, common northward. July.—The rootstock sends out slender underground stolons, which bear fronds the next year. (Eu.)
16. WOÓDSIA, R. Brown. ([Pl. 19.])
Fruit-dots round, borne on the back of simply-forked free veins; the very thin and often evanescent indusium attached by its base all around the receptacle, under the sporangia, either small and open, or else early bursting at the top into irregular pieces or lobes.—Small and tufted pinnately-divided ferns. (Dedicated to Joseph Woods, an English botanist.)
[*] Stalks obscurely articulated some distance from the base; fronds chaffy or smooth, never glandular; indusium divided nearly to the centre into slender hairs which are curled over the sporangia.
1. W. Ilvénsis, R. Brown. Frond oblong-lanceolate (2–6´ long by 12–18´´ wide), smoothish and green above, thickly clothed underneath as well as the stalk with rusty bristle-like chaff, pinnate; the pinnæ crowded, oblong, obtuse, sessile, pinnately parted, the numerous crowded segments oblong, obtuse, obscurely crenate; the fruit-dots near the margin, somewhat confluent when old.—Exposed rocks; common, especially northward, and southward in the Alleghanies. June. (Eu.)
2. W. hyperbòrea, R. Brown. Frond narrowly oblong-lanceolate (2–6´ long by 8–12´´ wide), smooth above, sparingly paleaceous-hirsute beneath, pinnate; the pinnæ triangular-ovate, obtuse, pinnately lobed, the lobes few and nearly entire; fruit-dots rarely confluent.—Mountain ravines, northern Vt. and N. Y., and northward; rare. (Eu.)
3. W. glabélla, R. Brown. ([Pl. 19], fig. 1–3.) Smooth and naked throughout; frond linear and very delicate (2–5´ high), pinnate; pinnæ roundish-ovate, the lower ones rather remote (2–4´´ long), obtuse, crenately lobed; fruit-dots scanty; the hairs of the indusium fewer than in the last two species.—On moist mossy rocks, mountains of northern New Eng., north and westward. First found at Little Falls, N. Y., by Dr. Vasey. (Eu.)
[*][*] Stalks not articulated; fronds never chaffy, often glandular-pubescent.
[+] Indusium of a few broad segments, at first covering the sorus completely.
4. W. obtùsa, Torr. ([Pl. 19], fig. 4, 5.) Frond broadly lanceolate, minutely glandular-hairy (6–12´ high), pinnate, or nearly twice pinnate; pinnæ rather remote, triangular-ovate or oblong (1–2´ long), bluntish, pinnately parted; segments oblong, obtuse, crenately toothed, the lower pinnatifid with toothed lobes; veins forked, and bearing the fruit-dots on or below the minutely toothed lobes; indusium at length splitting into several spreading jagged lobes.—Rocky banks and cliffs; not rare.