14. Cystopteris. Indusium convex, fixed by a broad base partly under the sorus, commonly reflexed as the sporangia ripen.

[*][*][*] Indusium obscure, irregularly semicircular. Fertile fronds much contracted and very unlike the sterile ones.

15. Onoclea. Sporangia on an elevated receptacle; divisions of the fertile frond pod-like or berry-like.

Tribe VII. WOODSIEÆ. Sori round, borne on the veins; indusium fixed under the sorus, divided into segments or into slender filaments.

16. Woodsia. Small ferns with free veins. Indusium very delicate.

Tribe VIII. DICKSONIEÆ. Sori roundish, marginal or submarginal. Indusium cup-shaped or two-valved, the outer portion composed of a reflexed lobule of the frond, or more or less united to it.

17. Dicksonia. Indusium in our species small, membranaceous, nearly globular. Frond elongated, decompound.

Suborder II. Hymenophyllàceæ. Sporangia sessile on a bristle-like receptacle within a cup-shaped or bivalvular involucre, the ring transverse and complete. Fronds delicately membranaceous.

18. Trichomanes. Involucres funnel-form or cup-shaped.

Suborder III. Schizæàceæ. Sporangia ovate, sessile, having a complete transverse articulated ring at the apex, and opening by a longitudinal slit. (Pl. 19.)

19. Schizæa. Sporangia naked, fixed in a double row to the midrib of the narrow fertile segments. Sterile fronds rigid, simple or dichotomously branched.

20. Lygodium. Sporangia borne in a double row on narrow fertile segments, each sporangium seated on a separate veinlet, and provided with a special scale-like indusium. Fronds leafy, climbing.

Suborder IV. Osmundàceæ. Sporangia naked, globose, mostly pedicelled, reticulated, with no ring or mere traces of one near the apex, opening into two valves by a longitudinal slit. Stipes winged at base and almost stipulate! (Pl. 19.)

21. Osmunda. Fertile pinnæ or fronds very much contracted, bearing the abundant and large sporangia upon the margins of the very narrow segments. Veins free.

1. POLYPÒDIUM, L. Polypody. (Pl. 16.)

Fruit-dots round, naked, arranged on the back of the frond in one or more rows each side of the midrib or central vein, or irregularly scattered, each borne in our species on the end of a free veinlet. Rootstocks creeping, branched, often covered with chaffy scales, bearing scattered roundish knobs, to which the stipes are attached by a distinct articulation. (Name from πολύς, many, and ποῦς, foot, alluding to the branching rootstock.)

1. P. vulgàre, L. (Pl. 16, fig. 1–3.) Fronds evergreen, oblong, smooth both sides, 4–10´ high, simple and deeply pinnatifid; the divisions linear-oblong, obtuse or somewhat acute, remotely and obscurely toothed; veins once or twice forked; fruit-dots large, midway between the midrib and the margin.—Rocks; common. July. (Eu.)

2. P. incànum, Swartz. Fronds evergreen and coriaceous, oblong, 2–6´ high, grayish and very scurfy underneath with peltate scales, simply pinnatifid; the divisions oblong-linear, obtuse; fruit-dots rather small, near the margin; veins forking, free in the N. American plant!—Rocks and trunks of trees, Va. and Ohio to Ill., and southward. Aug.

2. NOTHOLÆ̀NA, R. Brown. Cloak-fern.

Fruit-dots roundish or oblong, placed near the ends of the veins, soon more or less confluent into an irregular marginal band, with no proper involucre. Veins always free. Fronds of small size, 1–4-pinnate, the lower surface almost always either hairy, tomentose, chaffy, or covered with a fine waxy white or yellow powder. (Name from νόθος, spurious, and λαῖνα, a cloak, the woolly coating of the original species forming a spurious covering to the sporangia.)

1. N. dealbàta, Kunze. Fronds triangular-ovate, 1–3´ long, 3–4-pinnate; rhachis and branches straight, black and shining; ultimate pinnules scarcely a line long, white and powdery on the lower surface.—Clefts of calcareous rocks, Mo., Kan., and southwestward. July–Aug.

3. ADIÁNTUM, L. Maidenhair. (Pl. 17.)

Fruit-dots marginal, short, borne on the under side of a transversely oblong, crescent-shaped or roundish, more or less altered margin or summit of a lobe or tooth of the frond reflexed to form an indusium; the sporangia attached to the approximated tips of the free forking veins.—Main rib (costa) of the pinnules none (in our species), or at the lower margin. Stipes black and polished. (The ancient name, from α privative and διαίνω, meaning unwetted, the smooth foliage repelling rain-drops.)

1. A. pedàtum, L. (Pl. 17, fig. 1–3.) Frond forked at the summit of the upright slender stalk (9–15´ high), the recurved branches bearing on one side several slender spreading pinnate divisions; pinnules numerous, short-stalked and obliquely triangular-oblong, entire on the lower margin, from which the veins all proceed, and cleft and fruit-bearing on the other.—Rich, moist woods. July.—A delicate and most graceful Fern.

2. A. Capíllus-Véneris, L. Fronds with a continuous main rhachis, ovate-lanceolate, 9–18´ long, often pendent, 2–3-pinnate at the base, the upper third or half simply pinnate; pinnules wedge-obovate or rhomboid, 6–12´´ long, deeply and irregularly incised; veinlets flabellately forking from the base; involucres lunulate or transversely oblong.—Moist rocky places, Va. to Mo., and southward. (Eu.)

4. PTÈRIS, L. Brake or Bracken. (Pl. 17.)

Sporangia in a continuous slender line of fructification, occupying the entire margin of the fertile frond, and covered by its reflexed narrow edge which forms a continuous membranaceous indusium, attached to an uninterrupted transverse vein-like receptacle connecting the tips of the forked free veins.—Fronds 1–3-pinnate or decompound. (The ancient Greek name of Ferns, from πτερόν, a wing, on account of the prevalent pinnate or feathery fronds.)

1. P. aquilìna, L. (Common Brake.) Frond dull green (2–3° wide), ternate at the summit of an erect stout stalk (1–2° high), the widely spreading branches twice pinnate; pinnules oblong-lanceolate; the upper undivided; the lower more or less pinnatifid, with oblong obtuse lobes, margined all round with the indusium, which is really double in this species.—Var. caudàta, with the lobes very narrow and revolute, the terminal ones much elongated, is a southern form, which extends in a modified condition as far north as New Jersey.—Thickets and hillsides, common. Aug. (Eu.)

5. CHEILÁNTHES, Swartz. Lip-fern. (Pl. 17.)

Sporangia borne on the thickened ends of free veinlets, forming small and roundish distinct or nearly contiguous marginal fruit-dots, covered by a mostly whitish and membranaceous, sometimes herbaceous, common indusium, formed of the reflexed margin of separate lobes or of the whole pinnule.—Low, mostly with 2–3-pinnate and hairy or chaffy, rarely smooth fronds, the sterile and fertile nearly alike, the divisions with the principal vein central. Some species with continuous indusium connect this genus very closely with the next. (Name composed of χεῖλος, a lip, and ἄνθος, flower, from the shape of the indusium.)

[*] Fronds smooth, or at most hairy.

1. C. Alabaménsis, Kunze. Fronds smooth, chartaceous (2–8´ long), ovate-lanceolate, bipinnate; pinnæ numerous, oblong-lanceolate; pinnules triangular-oblong, rather acute, often auriculate or lobed; indusium continuous, rather broad, pale, and of firm consistence.—On rocks, mountains of Va. to Ky., and southward.

2. C. vestìta, Swartz. (Pl. 17, fig. 1, 2.) Fronds (6–15´ high), lanceolate-oblong, hirsute, as are the brown and shining stipes, with straightish prominently articulated rusty hairs, twice pinnate; pinnæ rather distant, triangular-ovate; pinnules oblong, crowded (2–4´´ long), more or less incised, the ends of the roundish or oblong lobes reflexed and forming separate herbaceous involucres, which are pushed back by the ripened sporangia.—Clefts of rocks, Manhattan Island (W. W. Denslow) and N. J. to Ill., and southward.

[*][*] Fronds woolly or tomentose.

3. C. tomentòsa, Link. Fronds (12–20´ high) lanceolate-oblong, densely tomentose with slender and entangled whitish obscurely articulated hairs, thrice pinnate; primary and secondary pinnæ oblong or ovate-oblong; pinnules distinct, minute (½–1´´ long), roundish-obovate, sessile or adnate-decurrent, the upper surface less woolly, the reflexed narrow margin forming a continuous somewhat membranaceous indusium.—Mountains of Va. and Ky.; thence west and southward.—Stipe and rhachis rather stout, brown, covered with narrow chaffy scales and whitish hairs.

6. PELLÆ̀A, Link. Cliff-Brake. (Pl. 16.)

Sporangia in roundish or elongated clusters on the upper part of the free veins, distinct, or confluent laterally so as to imitate the marginal continuous line of fructification of Pteris, commonly covered by a broad membranaceous and continuous (rarely interrupted) general indusium, which consists of the reflexed and altered margin of the fertile pinnule or division. Small ferns, with 1–3-pinnate fronds, the fertile ones with narrower divisions than the sterile, but otherwise similar. Stipes generally dark-colored, smooth and shining. (Name from πελλός, dusky, alluding to the stipe.)

1. P. grácilis, Hook. (Pl. 16.) Fronds smooth (3–6´ high), delicately membranaceous and slender, of few pinnæ, the lower ones once or twice pinnately parted into 3–5 decurrent divisions, those of the fertile frond oblong or linear-oblong, entire or sparingly incised; of the sterile ovate or obovate, crenate or incised; veins of the fertile fronds mostly only once forked.—Shaded calcareous rocks, Mass. to Minn., and northward; rare. July.—Rootstock very slender, creeping; stipes polished, brownish, darker and sparingly chaffy at base.

2. P. atropurpùrea, Link. Smooth, except some bristly-chaffy hairs on the midribs and especially on the dark purple and polished stalk and rhachis, 6–15´ high; frond coriaceous, pale, once or below twice pinnate; the divisions broadly linear or oblong, or the sterile sometimes oval, chiefly entire, somewhat heart-shaped or else truncate at the stalked base; veins about twice forked.—Dry calcareous rocks; not common, but of wide range. July.—Rootstock short and stout; stipes clustered.

7. CRYPTOGRÁMME, R. Brown. Rock-Brake.

Fruit-dots roundish or elongated and extending far down on the free forking veins. True involucre or indusium none, the herbaceous margins of the fertile segments at first reflexed and meeting at the midrib, at length opening out flat and exposing the confluent sporangia.—Low ferns, with smooth, 2–3-pinnate fronds, the fertile ones taller than the sterile, and with much narrower divisions. (Name from κρυπτός, hidden, and γραμμή, a line, alluding to the lines of sporangia at first concealed by the reflexed margin.)

1. C. acrostichoìdes, R. Brown. Stipes densely tufted, straw-colored; fronds 2–3-pinnate (6–10´ high); fertile segments stalked, linear or linear-oblong (3–5´´ long), the sporangia in lines extending down the veins almost to the midrib, confluent when ripe and covering the under surface of the now fully opened segments; sterile fronds on much shorter stipes, with ovate or obovate decurrent and crenately toothed or incised segments. (Allosorus acrostichoides, Sprengel.)—On rocks, from L. Superior westward and northward.—Very near C. crispa of Eu.

8. WOODWÁRDIA, Smith. Chain-fern. (Pl. 17.)

Fruit-dots oblong or linear, arranged in one or more chain-like rows on transverse anastomosing veinlets parallel and near to the midrib. Indusium fixed by its outer margin to the fruitful veinlet, free and opening on the side next the midrib. Veins more or less reticulated, free toward the margin of the frond.—Large ferns, with pinnatifid or pinnate fronds. (Named for Thomas J. Woodward, an English botanist.)

§ 1. ANCHÍSTEA. Sterile and fertile fronds alike; veins forming only one row of meshes (areoles).

1. W. Virgínica, Smith. (Pl. 17, fig. 4, 5.) Fronds (2–3° high) pinnate, with numerous lanceolate pinnatifid pinnæ; segments oblong; veins forming a row of narrow areoles along the midrib both of the pinnæ and of the lobes, the outer veinlets free; fruit-dots oblong, one to each areole, confluent when ripe.—Wet swamps, Maine to Ark., and southward. Rootstocks creeping, often 6–8° long! July.

§ 2. LORINSÈRIA. Sterile and fertile fronds unlike; veins of the sterile fronds forming many rows of meshes.

2. W. angustifòlia, Smith. (Pl. 17, fig. 1–3.) Fronds pinnatifid; sterile ones (12–18´ high) with lanceolate serrulate divisions united by a broad wing; fertile fronds taller, with narrowly linear almost disconnected divisions, the areoles and fruit-dots (4–5´´ long) in a single row each side of the secondary midribs; rootstocks creeping.—Wet woods, New Eng., near the coast, to Ark., and southward; rare. Aug., Sept.

9. ASPLÈNIUM, L. Spleenwort. (Pl. 18.)

Fruit-dots oblong or linear, oblique, separate; the straight, or rarely curved, indusium fixed lengthwise by one edge to the upper (inner) side of the fertile vein;—in some species a part of the fruit-dots are double, the fertile vein bearing two indusia placed back to back. Veins free in all our species. (Name from α- privative and σπλήν, the spleen, for supposed remedial properties.)

§ 1. ASPLENIUM proper. Indusium straight or slightly curved, attached to the upper side of the vein, rarely double.

[*] Small evergreen ferns; fronds pinnatifid, or pinnate only near the base.

1. A. pinnatífidum, Nutt. Fronds (3–6´ long) lanceolate, pinnatifid, or pinnate below, tapering above into a slender prolongation, "the apex sometimes rooting"; lobes roundish-ovate, obtuse, or the lowest pair long-acuminate; fruit-dots irregular, those next the midrib often double, even the slender prolongation fertile.—On cliffs and rocks, Penn. to Mo., and southward; very rare. July.—Resembles the Walking-Leaf (Camptosorus), but the veins are free. Stipes brownish, becoming green above, and so passing into the broad pale green midrib.

2. A. ebenoìdes, R. R. Scott. Fronds (4–9´ long) broadly lanceolate pinnatifid, below pinnate, the apex prolonged and slender; divisions lanceolate from a broad base, the lower ones shorter, often proliferous, as is the apex of the frond; fruit-dots much as in the last; stipes black and polished, as is the lower part of the midrib, especially beneath.—Limestone cliffs, Conn. and Penn., and southward; very rare, usually growing with Camptosorus and Asplenium ebeneum, of which Rev. M. G. Berkeley considered it a probable hybrid.

9. A. Rùta-murària, L. Fronds deltoid-ovate (1–2½´ long), subcoriaceous, laxly 2–3-pinnate at base, the pinnæ alternate; ultimate segments few, stalked (2–5´´ long), from narrowly cuneate to roundish-obovate, toothed or incised at the apex; veins forking; sori 2–4 on a segment.—Limestone cliffs, Vt. to Mich., and southward; scarce. July. (Eu.)

11. A. thelypteroìdes, Michx. (Pl. 18, fig. 1, 2.) Fronds (2–3° high) pinnate; pinnæ deeply pinnatifid, linear-lanceolate (3–5´ long); the lobes oblong, obtuse, minutely toothed, crowded, each bearing 3–6 pairs of oblong fruit-dots, some of them double.—Rich woods; not rare. July–Sept.

§ 2. ATHÝRIUM. Indusium delicate, curved, often crossing the vein, and attached to both sides of it, thus becoming reniform, or shaped like a horseshoe.

12. A. Filix-fœ́mina, Bernh. Fronds (1–3° high) ovate-oblong or broadly lanceolate, twice pinnate; pinnæ lanceolate, numerous; pinnules confluent on the secondary rhachis by a narrow margin, oblong and doubly serrate, or elongated and pinnately incised with cut-toothed segments; fruit-dots short, variously curved, at length confluent.—Moist woods; common and presenting many varying forms. July. (Eu.)

10. SCOLOPÉNDRIUM, Smith. Hart's-Tongue. (Pl. 18.)

Fruit-dots linear, elongated, almost at right angles to the midrib, contiguous by twos, one on the upper side of one veinlet, and the next on the lower side of the next superior veinlet, thus appearing to have a double indusium opening along the middle. (The ancient Greek name, so called because the numerous parallel lines of fruit resemble the feet of the centipede, or Scolopendra.)

1. S. vulgàre, Smith. Frond oblong-lanceolate from an auricled-heart-shaped base, entire or wavy-margined (7–18´ long, 1–2´ wide), bright green.—Shaded ravines and under limestone cliffs; central N. Y.; also in Canada and Tenn.; very rare. Aug. (Eu.)

11. CAMPTOSÒRUS, Link. Walking-Leaf. (Pl. 18.)

Fruit-dots oblong or linear, as in Asplenium, but irregularly scattered on either side of the reticulated veins of the simple frond, those next the midrib single, the outer ones inclined to approximate in pairs (so that their two indusia open face to face), or to become confluent at their ends, thus forming crooked lines (whence the name, from καμπτός, bent, and σωρός, for fruit-dot.)

1. C. rhizophýllus, Link. Fronds evergreen, sub-coriaceous, growing in tufts, spreading or procumbent (4–12´ long), gradually narrowed from a cordate or auricled base to a long and slender acumination, which often roots at the end and forms a new plant.—Shaded rocks, especially calcareous rocks, N. Eng. to Minn., and southward to Kan. and Ala.—The auricles are sometimes greatly elongated, and even rooting; in another form they are lacking, as in the thinner leaved C. Sibiricus. July.

12. PHEGÓPTERIS, Fée. Beech Fern.

13. ASPÍDIUM, Swartz. Shield Fern. Wood Fern. (Pl. 19.)

Fruit-dots round, borne on the back or rarely at the apex of the veins. Indusium covering the sporangia, flat or flattish, scarious, orbicular and peltate at the centre, or round-kidney-shaped and fixed either centrally or by the sinus, opening all round the margin. Stipe continuous (not articulated) with the rootstock.—Our species have free veins and 1–3-pinnate fronds. (Name, ἀσπίδιον, a small shield, from the shape of the indusium.)

§ 1. DRYÓPTERIS. Indusium reniform, or orbicular with a narrow sinus.

[*] Veins simple or simply forked and straight; fronds annual, decaying in autumn, the stalks and slender creeping rootstocks nearly naked.

1. A. Thelýpteris, Swartz. Fronds pinnate, lanceolate in outline; pinnæ horizontal or slightly recurved, linear-lanceolate, deeply pinnatifid, the lowest pairs scarcely smaller; lobes oblong, entire, obtuse or appearing acute when in fruit from the strongly revolute margins; veins mostly forked, bearing the (soon confluent) fruit-dots near their middle; indusium minute, smooth and naked.—Marshes; common. Aug.—Stalk 1° long or more, usually longer than the frond, which is of thicker texture than the next, and slightly downy. (Eu.)

2. A. Noveboracénse, Swartz. Fronds pinnate, lanceolate in outline, tapering both ways from the middle; pinnæ lanceolate, the lowest 2 or more pairs gradually shorter and deflexed; lobes flat, oblong, basal ones often enlarged and incised; veins simple, or forked in the basal lobes; fruit-dots distinct, near the margin; indusium minute, the margin glanduliferous.—Swamps and moist thickets; common. July.—Frond pale green, delicate and membranaceous, hairy beneath along the midribs and veins.

[+][+][+] Large (2–4° high); fronds once pinnate and the pinnæ deeply pinnatifid, or nearly twice pinnate; fruit-dots not very near the margin; the indusium large, thinnish and flat, persistent.

9. A. marginàle, Swartz. (Pl. 19, fig. 1, 2.) Frond evergreen, smooth, thickish and almost coriaceous, ovate-oblong in outline (1–2° long); pinnæ lanceolate, acuminate, slightly broadest above the base; pinnules oblong or oblong-scythe-shaped, crowded, obtuse or pointed, entire or crenately-toothed; fruit-dots close to the margin.—Rocky hillsides in rich woods; common, especially northward. Aug.

§ 2. POLÝSTICHUM. Indusium orbicular and entire, peltate, fixed by the depressed centre; fronds rigid and coriaceous, evergreen, very chaffy on the rhachis, etc.; pinnæ or pinnules auricled at base on the upper side, crowded, the teeth or lobes bristle-tipped.

10. A. acrostichoìdes, Swartz. (Christmas Fern.) (Pl. 19, fig. 3, 4.) Frond lanceolate (1–2½° high), stalked; pinnæ linear-lanceolate, somewhat scythe-shaped, half-halberd-shaped at the slightly stalked base, serrulate with appressed bristly teeth; the fertile (upper) contracted and smaller, bearing contiguous fruit-dots near the midrib, which are confluent with age, covering the surface.—Var. incìsum is a state with cut-lobed pinnæ, a not unfrequent case in the sterile fronds; sometimes with all the tips fertile.—Common in rocky woods, especially northward. July.

11. A. Lonchìtis, Swartz. Frond linear-lanceolate (9–20´ high), scarcely stalked, very rigid; pinnæ broadly lanceolate-scythe-shaped, or the lowest triangular, strongly auricled on the upper side, and wedge-truncate on the lower, densely spinulose-toothed (1´ or less in length), copiously fruit-bearing; fruit-dots contiguous and near the margins.—Woods, southern shore of Lake Superior, and northward. (Eu.)

[*][*] Fronds bipinnate.

12. A. aculeàtum, Swartz, var. Braùnii, Koch. Fronds spreading (1½–2° long), oblong-lanceolate in outline, with a tapering base, the lower of the many pairs of oblong-lanceolate pinnæ gradually reduced in size and obtuse; pinnules ovate or oblong, obtuse, truncate and almost rectangular at base, short-stalked, or the upper confluent, sharply toothed, beset with long and soft as well as chaffy hairs.—Deep woods, mountains of New Eng., N. Y., and Penn., and northward. (Eu.)

14. CYSTÓPTERIS, Bernhardi. Bladder Fern. (Pl. 19.)

Fruit-dots roundish, borne on the back of a straight fork of the free veins; the delicate indusium hood-like or arched, attached by a broad base on the inner side (toward the midrib) partly under the fruit-dot, early opening free at the other side, which looks toward the apex of the lobe, and is somewhat jagged, soon thrown back or withering away.—Tufted ferns with slender and delicate 2–3-pinnate fronds; the lobes cut-toothed. (Name composed of κύστις, a bladder, and πτερίς, fern, from the inflated indusium.)

1. C. bulbífera, Bernh. (Pl. 19, fig. 1–3.) Frond lanceolate, elongated (1–2° long), 2-pinnate; the pinnæ lanceolate-oblong, pointed, horizontal (1–2´ long); the rhachis and pinnæ often bearing bulblets underneath, wingless; pinnules crowded, oblong, obtuse, toothed or pinnatifid; indusium short, truncate on the free side.—Shaded ravines, not rare from N. Eng. to Ark., commoner on calcareous rocks. July.—Specimens from Tenn. and Ark. have sometimes shorter fronds and few or no bulblets, indicating an approach to the next species.

2. C. frágilis, Bernh. Frond oblong-lanceolate (4–8´ long, besides the brittle stalk which is fully as long), 2–3-pinnate; the pinnæ and pinnules ovate or lanceolate in outline, irregularly pinnatifid or cut-toothed, mostly acute, decurrent on the margined or winged rhachis; indusium tapering or acute at the free end.—Shaded cliffs and rocky woods; common and greatly varying in the shape and cutting of the pinnules. July. (Eu.)

15. ONOCLÈA, L. (Pl. 16 and 19.)

Sporangia borne on elevated receptacles, forming roundish sori imperfectly covered by very delicate hood-shaped indusia attached to the base of the receptacles. Fertile fronds erect, rigid, with contracted pod-like or berry-like divisions at first completely concealing the sporangia, and at last, when dry and indurated, cracking open and allowing the spores to escape. Sterile fronds foliaceous. Rootstocks creeping and constantly forming new plants. (Name apparently from ὄνος, a vessel, and κλείω, to close, from the singularly rolled up fructification.)

§ 1. ONOCLEA proper. Sterile frond with anastomosing veins.

1. O. sensíbilis, L. (Sensitive Fern.) (Pl. 19, fig. 1, 2.) Fronds scattered; the sterile ones long-stalked (2–15´ long), triangular-ovate, pinnatifid into a few oblong-lanceolate sinuately lobed or nearly entire segments; veins reticulated with fine meshes; fertile fronds contracted, closely bipinnate, the pinnules rolled up into berry-like bodies.—Moist meadows and thickets, very common and variable. July.—Imperfectly fertile fronds sometimes occur, with the still foliaceous pinnæ cut into obovate segments with free veins and abortive sori; the so-called var. obtusilobàta.

§ 2. STRUTHIÓPTERIS. Sterile frond with free veins.

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.

[+][+] Indusium entirely concealed beneath the sorus, divided into very narrow segments or reduced to minute hairs.

5. W. Oregàna, D. C. Eaton. Smooth, with fronds (2–8´ high, 8–12´´ wide) elliptical-lanceolate, pinnate, the fertile ones tallest; pinnæ triangular-oblong, obtuse, pinnatifid; segments oblong or ovate, obtuse, finely toothed, and in larger fronds incised; fruit-dots near the margin; indusium very small, divided almost to the centre into a few necklace-like-jointed cilia.—Crevices of rocks, south shore of Lake Superior (Robbins), and westward.

6. W. scopulìna, D. C. Eaton. Much like the last, but the rather larger fronds puberulent beneath with minute jointed hairs and stalked glands; indusium deeply cleft into narrow segments ending in jointed hairs.—Rocky places, Minn., southward and westward.

17. DICKSÒNIA, L'Her. (Pl. 17.)

Fruit-dots small, globular, marginal, each placed on the apex of a free vein or fork; the sporangia borne on an elevated globular receptacle, enclosed in a membranaceous cup-shaped indusium which is open at the top, and on the outer side partly adherent to a reflexed toothlet of the frond. (Named for James Dickson, an English Cryptogamic botanist.)

1. D. pilosiúscula, Willd. Fronds minutely glandular and hairy (2–3° high), ovate-lanceolate and acuminate in outline, pale green, very thin, with strong chaffless stalks rising from slender extensively creeping naked root-stocks, mostly bipinnate; primary pinnæ lanceolate, pointed, the secondary pinnatifid into oblong and obtuse cut-toothed lobes; fruit-dots minute, each on a recurved toothlet, usually one at the upper margin of each lobe. (D. punctilobula, Kunze.)—Common in moist and shady places, from New Eng. to Minn.—Frond sweet-scented in drying.

18. TRICHÓMANES, L. Filmy Fern.

19. SCHIZÆ̀A, Smith. (Pl. 20.)

Sporangia large, ovoid, striate-rayed at the apex, opening by a longitudinal cleft, naked, vertically sessile in a double row along the single vein of the narrow divisions of the pinnate (or radiate) fertile appendages to the slender and simply linear, or (in foreign species) fan-shaped or dichotomously many-cleft fronds (whence the name, from σχίζω, to split).

1. S. pusílla, Pursh. Sterile fronds linear, very slender, flattened and tortuous; the fertile ones equally slender (¼´´ wide), but taller (3–4´ high), and bearing at the top the fertile appendage, consisting of about 5 pairs of crowded pinnæ (each 1–1½´´ long).—Low grounds, pine barrens of N. J.; very local. Sept. (Also in Nova Scotia and Newf.)

20. LYGÒDIUM, Swartz. Climbing Fern. (Pl. 20.)

Fronds twining or climbing, bearing stalked and variously lobed (or compound) divisions in pairs, with mostly free veins; the fructification on separate contracted divisions or spike-like lobes, one side of which is covered with a double row of imbricated hooded scale-like indusia, fixed by a broad base to short oblique veinlets. Sporangia much as in Schizæa, but oblique, fixed to the veinlet by the inner side next the base, one or rarely two covered by each indusium. (Name from λυγώδης, flexible.)

1. L. palmàtum, Swartz. Very smooth; stalks slender, flexile and twining (1–3° long), from slender running rootstocks; the short alternate branches or petioles 2-forked; each fork bearing a round-heart-shaped palmately 4–7-lobed frondlet; fertile frondlets above, contracted and several times forked, forming a terminal panicle.—Low moist thickets and open woods, Mass. to Va., Ky., and sparingly southward; rare. Sept.

21. OSMÚNDA, L. Flowering Fern. (Pl. 20.)

Fertile fronds or fertile portions of the frond destitute of chlorophyll, very much contracted, and bearing on the margins of the narrow rhachis-like divisions short-pedicelled and naked sporangia; these are globular, thin and reticulated, large, opening by a longitudinal cleft into two valves, and bearing near the apex a small patch of thickened oblong cells, the rudiment of a transverse ring.—Fronds tall and upright, growing in large crowns from thickened rootstocks, once or twice pinnate; veins forking and free. Spores green. (Osmunder, a Saxon name of the Celtic divinity, Thor.)

2. O. Claytoniàna, L. (Pl. 20, fig. 1–3.) Clothed with loose wool when young, soon smooth; fertile fronds taller than the sterile (2–4° high); pinnæ oblong-lanceolate, with oblong obtuse divisions; some (2–5 pairs) of the middle pinnæ fertile, these entirely pinnate; sporangia greenish, turning brown.—Low grounds, common. May.—Fruiting as it unfolds.

3. O. cinnamòmea, L. (Cinnamon Fern.) Clothed with rusty wool when young; sterile fronds tallest (at length 3–5° high), smooth when full grown, the lanceolate pinnæ pinnatifid into broadly oblong obtuse divisions; fertile fronds separate, appearing earlier from the same rootstock and soon withering (1–2° high), contracted, twice pinnate, covered with the cinnamon-colored sporangia.—Var. frondòsa is a rare occasional state, in which some of the fronds are sterile below and more sparsely fertile at their summit, or rarely in the middle.—Swamps and low copses, everywhere. May.

Order 132. OPHIOGLOSSÀCEÆ. (Adder's-Tongue Family.)

Leafy and often somewhat fleshy plants; the leaves (fronds) simple or branched, often fern-like in appearance, erect in vernation, developed from underground buds formed either inside the base of the old stalk or by the side of it, and bearing in special spikes or panicles rather large subcoriaceous bivalvular sporangia formed from the main tissue of the fruiting branches. Prothallus underground, not green, monœcious.—A small order, separated from Ferns on account of the different nature of the sporangia, the erect vernation, etc.

1. Botrychium. Sporangia in pinnate or compound spikes, distinct. Veins free.

2. Ophioglossum. Sporangia cohering in a simple spike. Veins reticulated.

1. BOTRÝCHIUM, Swartz. Moonwort. (Pl. 20.)

Rootstock very short, erect, with clustered fleshy roots (which are full of starch, in very minute, irregular granules!); the base of the naked stalk containing the bud for the next year's frond; frond with an anterior fertile and a posterior sterile segment; the former mostly 1–3-pinnate, the contracted divisions bearing a double row of sessile naked sporangia; these are distinct, rather coriaceous, not reticulated, globular, without a ring, and open transversely into two valves. Sterile segment of the frond ternately or pinnately divided or compound; veins all free. Spores copious, sulphur-color. (Name a diminutive of βότρυς, a cluster of grapes, from the appearance of the fructification.)

5. B. ternàtum, Swartz. (Pl. 20.) Plant very fleshy (4–16´ high), sparsely hairy; sterile segment long-petioled from near the base of the plant, broadly triangular, ternate and variously decompound with stalked divisions; ultimate segments varying from roundish-reniform and sub-entire to ovate-lanceolate and doubly incised; fertile segment erect, 2–4-pinnate.—The following varieties pass into each other:—Var. austràle; frond ample; ultimate segments rhomboid-ovate with a denticulate margin.—Var. intermèdium; frond of moderate size; ultimate segments as in var. australe. (B. lunarioides, of last ed.)—Var. rutæfòlium; frond small; ultimate segments few, ovate and semicordate.—Var. lunarioìdes; frond small; ultimate segments roundish-reniform.—Var. oblìquum; frond moderate; ultimate segments obliquely lanceolate, denticulate or toothed.—Var. disséctum; segments dissected into innumerable narrow lobes or teeth.—Pastures and hillsides, sometimes in dry woods, rather common, especially vars. intermedium and obliquum.—Var. rutæfolium occurs in Europe.

§ 2. OSMUNDÓPTERIS. Base of the stalk containing the bud open along one side; sterile segment membranaceous; the cells of the epidermis flexuous.

2. OPHIOGLÓSSUM, L. Adder's-Tongue. (Pl. 20.)

Rootstock erect, fleshy and sometimes tuberous, with slender fleshy roots which are sometimes proliferous; bud placed by the side of the base of the stalk; fronds with anterior and posterior segments as in Botrychium, but the coriaceous sporangia connate and coherent in two ranks on the edges of a simple spike. Sterile segment fleshy, simple in our species; the veins reticulated. Spores copious, sulphur-yellow. (Name from ὄφις, a serpent, and γλῶσσα, tongue.)

1. O. vulgàtum, L. Fronds from a slender rootstock (2–12´ high), mostly solitary; sterile segment sessile near the middle of the plant, ovate or elliptical (1–3´ long); midvein indistinct or none; veins forming small meshes enclosed in larger ones.—Bogs and pastures; not common. July. (Eu.)

Order 133. LYCOPODIÀCEÆ. (Club-Moss Family.)

Low plants, usually of moss-like aspect, with elongated and often much branched stems covered with small lanceolate or subulate, rarely oblong or rounded, persistent entire leaves; the sporangia 1–3-celled, solitary in the axils of the leaves, or on their upper surface, when ripe opening into two or three valves, and shedding the numerous yellow spores, which are all of one kind.—The Order, as here defined, consists mainly of the large genus

1. LYCOPÒDIUM, L. Club-Moss. (Pl. 21.)

Spore-cases coriaceous, flattened, usually kidney-shaped, 1-celled, 2-valved, mostly by a transverse line round the margin, discharging the subtile spores in the form of a copious sulphur-colored inflammable powder.—Perennials, with evergreen one-nerved leaves, imbricated or crowded in 4–16 ranks. (Name compounded of λύκος, a wolf, and ποῦς, foot, from no obvious resemblance.)

§ 1. Spore-cases in the axils of the ordinary (dark green and shining, rigid, lanceolate, about 8-ranked) leaves.

1. L. Selàgo, L. Stems erect and rigid, dichotomous, forming a level-topped cluster (3–6´ high); leaves uniform, crowded, ascending, glossy, pointed, entire or denticulate; sporangia in the axils of unaltered leaves.—Mountain-tops, Maine to Lake Superior, and northward.—The leaves of this and the next species often bear little gemmæ, with the lower bracts pointed, and the 2–3 uppermost broadly obovate and fleshy, as figured in 1768 by Dillenius. These gemmæ fall to the ground and their axis grows into the stem of a new plant, as specimens collected in 1854 show very plainly. (For their true nature see Sachs' Lehrbuch, Engl. trans., p. 411.)

[+][+] Spikes peduncled, i.e. the leaves minute on the fertile branches.

8. L. Caroliniànum, L. (Pl. 21.) Sterile stems and their few short branches entirely creeping (leafless and rooting on the under side), thickly clothed with broadly lanceolate acute and somewhat oblique 1-nerved lateral leaves widely spreading in 2 ranks, and a shorter intermediate row appressed on the upper side; also sending up a slender simple peduncle (2–4´ high, clothed merely with small bract-like and appressed awl-shaped leaves), bearing a single cylindrical spike.—Wet pine-barrens, N. J. to Va., and southward.

9. L. complanàtum, L. (Ground-Pine.) Stems extensively creeping (often subterranean), the erect or ascending branches several times forked above; bushy branchlets crowded, flattened, fan-like and spreading, all clothed with minute imbricated-appressed awl-shaped leaves in 4 ranks, with decurrent-united bases, the lateral rows with somewhat spreading tooth-like tips, those of the upper and under rows smaller, narrower, wholly appressed; peduncle slender, bearing 2–4 cylindrical spikes.—Var. Chamæcyparíssus has narrower, more erect and bushy branches, and the leaves less distinctly dimorphous.—Woods and thickets; common, especially northward. (Eu.)

Order 134. SELAGINELLÀCEÆ.

Leafy plants, terrestrial or rooted in mud, never very large; the stems branching or short and corm-like; the leaves small and 4–6-rowed, or subulate and elongated; sporangia one-celled, solitary, axillary or borne on the upper surface of the leaf at its base and enwrapped in its margins, some containing large spores (macrospores) and others small spores (microspores). The macrospores are in the shape of a low triangular pyramid with a hemispherical base, and marked with elevated ribs along the angles. In germination they develop a minute prothallus which bears archegonia to be fertilized by antherozoids developed from the microspores.

1. Selaginella. Terrestrial; stems slender; leaves small; sporangia minute and axillary.

2. Isoetes. Aquatic or growing in mud; stems corm-like: leaves elongated and rush-like; sporangia very large, enwrapped by the dilated bases of the leaves.

1. SELAGINÉLLA, Beauv. (Pl. 21.)

Fructification of two kinds, namely, of minute and oblong or globular spore-cases, containing reddish or orange-colored powdery microspores; and of mostly 2-valved tumid larger ones, filled by 3 or 4 (rarely 1–6) much larger globose-angular macrospores; the former usually in the upper and the latter in the lower axils of the leafy 4-ranked sessile spike, but sometimes the two kinds are on opposite sides all along the spike. (Name a diminutive of Selago an ancient name of a Lycopodium, from which this genus is separated, and which the plants greatly resemble in habit and foliage.)