[Illustration: Interrupted Fern. Osmunda Claytoniàna]
The fronds have a bluish-green tint; they mature their spores about the last of May. The sterile fronds may be distinguished from those of the cinnamon fern by not having retained, like those, a tuft of wool at the base of each pinna. Besides, in Clayton's fern the fronds are broader, blunter and thinner in texture, and the segments more rounded; the fronds are also more inclined to curve outwards. They turn yellow in the fall, at times "flooding the woods with golden light," but soon smitten by the early frosts they wither and disappear. The interrupted fern is rather common in damp, rocky woods and pastures; Newfoundland to Minnesota, south to North Carolina and Missouri. Although fond of moisture it is easily cultivated and its graceful outlines make it worthy of a prominent place in the fern garden. Var. dubia has the pinnules of the sterile frond widely separated, and the upper-middle ones much elongated. Southern Vermont.
[Illustration: Interrupted Fern with the Fertile Pinnules Spread Open]
Osmunda cinnamomea
Fronds one to six feet long, pinnate. Pinnæ lanceolate, pinnatifid with oblong, obtuse divisions. Fertile pinnæ on separate fronds, which are contracted and covered with brown sporangia.
[Illustration: Cinnamon Fern. Leaf Gradations]
[Illustration: Cinnamon Fern. Gradations from Sterile to Fertile Fronds]
[Illustration: Cinnamon Fern, var. frondosa]
Each fertile frond springs up at first outside the sterile ones, but is soon surrounded and overtopped by them and finds itself in the center of a charming circle of green leaves curving gracefully outwards. In a short time, however, it withers and hangs down or falls to the ground. The large, conspicuous clusters of cinnamon ferns give picturesqueness to many a moist, hillside pasture and swampy woodyard. In its crosier stage it is wrapped in wool, which falls away as the fronds expand, but leaves, at the base of each pinna, a tiny tuft, as if to mark its identity.
[Illustration: Cinnamon Fern, var. incisa (Maine)]
Many people in the country call the cinnamon fern the "buckhorn brake," and eat with relish the tender part which they find deep within the crown at the base of the unfolding fronds. This is known as the "heart of Osmund." The fern, itself, with its tall, recurving leaves makes a beautiful ornament for the shady lawn, and like the interrupted fern is easy to cultivate. The spores of all the osmundas are green, and need to germinate quickly or they lose their vitality. Common in low and swampy grounds in eastern North America and South America and Japan. May. Some think it was this species which was coupled with the serpent in the old rhyme,
"Break the first brake you see, Kill the first snake you see, And you will conquer every enemy."
[Illustration: Osmunda cinnamomea, var. glandulosa (From Waters's "Ferns," Henry Holt & Co.)]
Var. frondòsa has its fronds partly sterile below and irregularly fertile towards the summit.
Var. incìsa has the inner pinnules of some of the pinnæ more or less cut-toothed.
Var. glandulòsa has glandular hairs on the pinnæ, rachis and even the stipes of the sterile frond. This is known only on the coastal plain from Rhode Island to Maryland.
Small, slender ferns with linear or thready leaves, the sterile, one to two inches high and tortuous or "curled like corkscrews"; fertile fronds longer, three to five inches, and bearing at the top about five pairs of minute, fruited pinnæ. Sporangia large, ovoid, sessile in a double row along the single vein of the narrow divisions of the fertile leaves, and provided with a complete apical ring. (Schizæa, from a Greek root meaning to split, alluding to the cleft leaves of foreign species.)
[Illustration: Curly Grass. Schizæa pusilla]
The curly grass is so minute that it is difficult to distinguish it when growing amid its companion plants, the grasses, mosses, sundews, club mosses, etc. The sterile leaves are evergreen. Pine barrens of New Jersey, Grand Lake, Nova Scotia, and in New Brunswick. Several new stations for the curly grass have recently been discovered in the southwest counties of Nova Scotia by the Gray Herbarium expedition, mostly in bogs and hollows of sandy peat or sphagnum.
[Illustration: Sporangia of Curly Grass]
Fronds slender, climbing or twining, three to five feet long. The lower pinnæ (frondlets) sterile, roundish, five to seven lobed, distant in pairs with simple veins; the upper fertile, contracted, several times forked, forming a terminal panicle; the ultimate segments crowded, and bearing the sporangia, which are similar to those of curly grass, and fixed to a veinlet by the inner side next the base, one or rarely two covered by each indusium. (From the Greek meaning like a willow twig [pliant], alluding to the flexible stipes.)
[Illustration: Climbing Fern. Lygodium palmatum]
Fifty years ago this beautiful fern was more common than at present. There was a considerable colony in a low, alluvial meadow thicket at North Hadley, Mass., not far from Mt. Toby, where we collected it freely in 1872. Many used to decorate their homes with its handsome sprays, draping it gracefully over mirrors and pictures. It was known locally as the Hartford fern. Greedy spoilers ruthlessly robbed its colonies and it became scarce, at least in the Mt. Toby region. In Connecticut a law was enacted in 1867 for its protection and with good results. But as Mr. C.A. Weatherby states in the American Fern Journal (Vol. II, No. 4), the encroachments of tillage (mainly of tobacco, which likes the same soil), are forcing it from its cherished haunts, thus jeopardizing its survival. Doubtless an aggressive agriculture is in part responsible for its scarcity in the more northern locality. It is still found here and there in New England, New York and New Jersey; also in Kentucky, Tennessee and Florida, but is nowhere common. The fertile portion dies when the spores mature, but the sterile frondlets remain green through the winter. A handsome species for the fernery in the house or out of doors.
Plants more or less fern-like consisting of a stem with a single leaf. In Ophioglóssum the leaf or sterile segment is entire, the veins reticulated and the sporangia in a simple spike. In Botrýchium the sterile segment is more or less incised, the veins free, and the sori in a panicle or compound or rarely simple spike. Sporangia naked, opening by a transverse slit. Spores copious, sulphur-yellow.
ADDER'S TONGUE. Ophioglóssum vulgàtum
Rootstock erect, fleshy. Stem simple, two to ten inches high, bearing one smooth, entire leaf about midway, and a terminal spike embracing the sporangia, coherent in two ranks on its edges. (Generic name from the Greek meaning the tongue of a snake, in allusion to the narrow spike of the sporangia.)
In moist meadows or rarely on dry slopes. "Overlooked rather than rare." New England states and in general widely distributed. July. Often grows in company with the ragged orchis. The ancient ointment known as "adder's speare ointment" had the adder's tongue leaves as a chief ingredient, and is said to be still used for wounds in English villages.
[Illustration: Adder's Tongue. Ophioglossum vulgatum]
Var. minus, smaller; fronds often in pairs. The sterile segment yellowish-green, attached usually much below the middle of the plant. Sandy ground, New Hampshire to New Jersey.
Var. Engelmánni. (Given specific rank in Gray.) Has the sterile segment thicker and cuspidate, the stipe slender and the secondary veins forming a fine network within the meshes of the principal ones. Virginia and westward.
Var. arenàrium. (From the Latin, arèna, meaning sand, being found in a sandy soil.) Probably a depauperate form of Ophióglossum vulgàtum and about half as large. A colony of these ferns was discovered growing in poor soil at Holly Beach, New Jersey.
Rootstock very short, erect with clustered fleshy roots; the base of the sheathed stalk containing the bud for the next year's frond. Fertile frond one to three pinnate, the contracted divisions bearing a double row of sessile, naked, globular sporangia, opening transversely into two valves. Sterile segment of the frond ternately or pinnately divided or compound. Veins free. Spores copious, sulphur yellow. (The name in Greek means a cluster of grapes, alluding to the grape-like clusters of the sporangia.)
Very fleshy, three to ten inches high, sterile segment subsessile, borne near the middle of the plant, oblong, simple pinnate with three to eight pairs of lunate or fan-shaped divisions, obtusely crenate, the veins repeatedly forking; fertile segment panicled, two to three pinnate.
[Illustration: Moonwort Botrychium Lunaria]
[Illustration: Moonwort. Botrychium Lunaria. Details]
The moonwort was formerly associated with many superstitions and was reputed to open all locks at a mere touch, and to unshoe all horses that trod upon it. "Unshoe the horse" was one of the names given to it by the country people.
In dry pastures, Lake Superior and northward, but rare in the United States. Willoughby, Vt., where the author found a single plant in 1904, and St. Johnsbury, Vt. Also New York, Michigan and westward.
In England said to be local rather than rare. Sometimes called Lunary.
Fronds two to four inches high, very variable. Sterile segment short-petioled, usually near the middle, simple and roundish or pinnately three to seven lobed. Veins all forking from the base. Fertile segments simple or one to two pinnate, apex of both segments erect in the bud.
In moist woods and fields, Canada to Maryland and westward; Conway and Plainfield, Mass., Berlin and Litchfield, Conn. Rare. According to Pringle it is "abundantly scattered over Vermont, its habitat usually poor soil, especially knolls of hill pastures." May or June.
Frond two to nine inches high, both sterile and fertile segments at the top of the common stalk. Sterile segment triangular, twice pinnatifid, the acute lobes lanceolate, incised or toothed, scarcely fleshy, resembling a very small specimen of the rattlesnake fern. Fertile segment slightly overtopping the sterile, two to three pinnate and spreading.
One of the constant companions of the rattlesnake fern. New England to Lake Superior. July.
[Illustration: Little Grape Fern Botrychium simplex]
[Illustration: Lance-leaved Grape Fern Botrychium lanceolatum Botrychium angustisegmentum]
Fronds small, one to twelve inches high. Sterile segment above the middle, usually much divided. Fertile segment twice or thrice pinnate. Apex of both segments turned down in the bud, the sterile overtopping and clasping the fertile one.
[Illustration: The Matricary Fern Botrychium ramosum]
The matricary fern differs from the preceding in ripening its spores about a month earlier, in having its sterile frond stalked, besides being a taller and fleshier plant. It may also be noted that in the lance-leaved species the midveins of the larger lobes are continuous, running to the tip; whereas in the matricary fern the midveins fork repeatedly and are soon indistinguishable from the veinlets. The two are apt to grow near each other, with the rattlesnake fern as a near neighbor. June.
NOTE. In 1897 A.A. Eaton discovered certain Botrychia in a sphagnum swamp in New Hampshire, to which he gave the specific name of Botrychium tenebròsum. The plants were very small, not averaging above two or three inches high, with the sterile blade sessile or slightly stalked. Many botanists prefer to place this fern as a variety of the matricary, but others regard it as a form of Botrychium símplex. Borders of maple swamps, Vermont, New Hampshire, Massachusetts, and New York.
Rootstock short, its base including the buds of succeeding years. Fronds two to twelve inches or more high. Leafy or sterile segment triangular, ternate, long-petioled, springing from near the base of the plant, and spreading horizontally. From the main leafstock grow several pairs of stalked pinnæ, with the divisions ovate-oblong, acutish, crenate-serrulate, obliquely cordate or subcordate. Fertile segment taller, erect, about three times pinnate, maturing its fruit in autumn. Occasionally two or three fertile spikes grow on the same plant. In vernation the apex of each segment is bent down with a slight curve inward.
[Illustration: Common Grape Fern. Botrychium obliquum]
New England to Virginia, westward to Minnesota and southward.
Botrychium obliquum, var. dissectum. Similar to the type, but with the divisions very finely dissected or incisely many-toothed, the most beautiful of all the grape ferns. There is considerable variety in the cutting of the fronds. Maine to Florida and westward.
Botrychium oblìquum, var. oneidénse. Ultimate segments oblong, rounded at the apex, crenulate-serrate, less divided than any of the others and, perhaps, less common. Vermont to Central New York.
Botrychium oblìquum, var. elongàtum. Divisions lanceolate, elongated, acute.
[Illustration: Botrychium obliquum var. oneidense]
Note: A Botrychium not uncommon in Georgia and Alabama, named by Swartz B. lunarioides, deserves careful study. It is known as the "Southern Botrychium."
[Illustration: Botrychium obliquum, var. dissectum]
Leaf more divided than in oblìquum and the numerous segments not so long and pointed, but large, fleshy, ovate or obovate (including var. austràle), crenulate, and more or less toothed.
Sandy soil, pastures and open woods. More northerly in its range--New England and New York. Var. rutaefòlium. More slender, rarely over six or seven inches high; sterile segment about two inches broad, its divisions few, broadly ovate, the lowest sublunate. The first variety passes insensibly into the second.
[Illustration: Ternate Grape Fern Botrychium ternatum var. intermedium (Reduced)]
[Illustration: Ternate Grape Fern Botrychium ternatum var. intermedium (Two stocks, reduced)]
Fronds six inches to two feet high. Sterile segment sessile above the middle of the plant, broadly triangular, thin, membranaceous, ternate. Pinnules lanceolate, deeply pinnatifid; ultimate segments oblong or lanceolate and scarcely or not at all spatulate. Fertile part long-stalked, two to three pinnate, its ultimate segments narrow arid thick, nearly opaque in dried specimens. Mature sporangia varying from dark yellow-brown to almost black. Open sporangia close again and are flattened or of a lenticular form. In rich, deciduous woods, rather common and widely distributed.
[Illustration: Rattlesnake Fern. Botrychium virginianum (From Waters's "Ferns," Henry Holt & Co.)]
Prince Edward Island, Minnesota, south to Florida and Texas, and north to Newfoundland and Labrador.
Var. grácilis. A form much reduced in size.
Var. LAURENTIÀNUM. A conspicuous variety having thick and heavy sterile fronds less finely divided than the type, with the segments crowded to overlapping. Pinnules shorter than the type, tending to be ovate, outer segments strongly spatulate. Fertile spike relatively short and stout, strongly paniculate when well developed. Ultimate segments flat, folaceous, one mm. wide. Mostly confined to the limestone district near the Gulf of St. Lawrence, Labrador, Newfoundland, Quebec, Maine, and Michigan.
Var. INTERMEDIUM. Segments of sterile fronds ultimately much spatulate, previously ovate, not overlapping. Segments of fertile fronds ultimately narrowly flattened. (For this and the other varieties see Rhodora of September, 1919.) Nova Scotia, Maine, Vermont, Massachusetts, Connecticut, northern New York, Illinois, and Missouri.
Var. EUROPÀEUM. Fertile frond less finely dissected than in type. Ultimate segments more obtuse than in type; has but very slight tendency towards the spatulate form of the two previous varieties. Pinnules lanceolate, strongly decurrent so that the pinnæ are merely pinnatifid. In coniferous forests of Canada, and confined to calcareous regions. Quebec, New Brunswick, New Hampshire, Vermont, New York, Ontario, Montana, and British Columbia. Said to be rare even in Europe.
The filmy ferns are small, delicate plants with membranaceous, finely dissected fronds from slender, creeping rootstocks. Sporangia sessile on a bristle-like receptacle. There are about one hundred species, mostly tropical, only one of which grows as far north as Kentucky.
[Illustration: Filmy Fern Trichomanes Boschianum (From Waters' "Ferns", Henry Holt & Co.)]
Rootstocks creeping, filiform, stipes ascending, one to three inches long, thin, very delicate, pellucid, much divided, oblong-lanceolate, bipinnatifid. Rachis narrowly winged. Sporangia clustered around the slender bristle, which is the prolongation of a vein, and surrounded by a vase-like, slightly two-lipped involucre.
On moist, dripping sandstone cliffs, Kentucky to Alabama. Often called the "Killarney fern," as it grows about the lakes of Killarney in Ireland.
[Illustration: Fruiting Pinnules of Filmy Fern (From Waters's "Ferns." Henry Holt & Co.)]
[Illustration: Ostrich Fern]
[Illustration: Cinnamon Fern]
[Illustration: Marginal Shield Fern]
[Illustration: Lady Fern Crosiers]
[Illustration: Fiddleheads or Crosiers of Christmas Fern]
[The works of these authors are listed under "Fern Literature" in the following pages.]
EATON, DANIEL CADY. Born at Gratiot, Mich., September 12, 1834. His grandfather was Amos Eaton, noted botanist and author. Studied botany under his friend, Prof. Asa Gray, who had studied with Prof. John Torrey, who in turn was a pupil of Amos Eaton. Daniel C. was professor of botany in Yale College, for more than thirty years. A man of graceful and winsome personality, an authority on ferns, and widely known by his writings. His masterpiece was "The Ferns of North America" in two large, quarto volumes, beautifully illustrated. He died June 29, 1895.
CLUTE, WILLARD NELSON. Born at Painted Post, N.Y., February 26, 1869. Education informal; common schools, university lectures and private study. Manifested early a keen interest in birds and flowers. Was founder and first president of the American Fern Society. Collected in Jamaica more than three hundred species of ferns. Has written extensively on the ferns and their allies, besides publishing several standard volumes. His great distinction is in founding and editing the Fern Bulletin through its twenty volumes, when he combined this publication with The American Botanist, which is now on its twenty-eighth volume, the whole a prodigious achievement of great scientific value.
[Illustration: Noted Writers on Ferns W.N. CLUTE, D.C. EATON, F.T. PARSONS, G. DAVENPORT, J. WILLIAMSON, L.M. UNDERWOOD, W.R MAXON, A.A. EATON, C.E. WATERS, R. DODGE]
UNDERWOOD, LUCIUS MARCUS. Born at New Woodstock, N.Y., October 26, 1853. Spent early life on a farm. Was graduated from Syracuse University in 1877. After teaching several years in his alma mater and elsewhere, he became Professor of Botany in Columbia University. He contributed numerous articles to the Torrey Bulletin, Fern Bulletin, and other scientific journals. His scholarly book, "Our Native Ferns and Their Allies," continued unexcelled through six editions. He died November 16, 1907.
DAVENPORT, GEO. EDWARD. Born in Boston, August 3, 1833. A promoter and officer of the Middlesex Institute. An accurate and diligent student of the ferns, his numerous articles were published in the Fern Bulletin, in the Torrey Bulletin, Rhodora, and in separate monographs. He was a leading authority on the pteridophyta, and collected a large and choice herbarium of the native ferns, which he donated to the Massachusetts Horticultural Society. By his gentle manners and kindly spirit he won many friends, all of whom were proud to recognize his distinguished ability. He cultivated many of our rare native ferns in his Fellsway home, at Medford, Mass., and freely gave specimens to his friends. He died suddenly of heart failure, November 29, 1907.
WATERS, CAMPBELL EASTER. Born in Baltimore County, Md., September 14, 1872. Was graduated at Johns Hopkins University in 1895. Ph.D. in 1899. Was for a time a close student of ferns, and issued his notable book, "Ferns," in 1903, containing his "Analytical Key Based on the Stipes." A chemist by profession, he has pursued that branch of science for the last eighteen years. His address is Bureau of Standards, Washington, D.C.
MAXON, WILLIAM RALPH. Born at Oneida, N.Y., February 27, 1877. Was graduated at Syracuse University in 1898. Began as aid in cryptogamic botany, United States National Herbarium, 1899, and is now associate curator of the same. Has specialized in scientific work on the pteridophyta, distinguishing himself by the excellence as well as by the large number of his publications, the more important being "Studies of Tropical American Ferns," Nos. 1 to 6. The Fern Bulletin, Torrey Bulletin, American Fern Journal, Fernwort Papers, et al., have profited from his expert and up-to-date knowledge. He is president of the American Fern Society.
PARSONS, FRANCES THEODORA. Born in New York, December 5, 1861. Née Smith. Married Commander William Starr Dana of the United States Navy, who was lost at sea. As Mrs. Dana, she published, "How to Know the Wild Flowers," in 1893, and within ten years more than seventy thousand copies of the book had been sold. "According to Season" appeared in 1894. In February, 1896, she married Prof. James Russell Parsons, treasurer of the University of the State of New York. In 1899 she published, "How to Know the Ferns." She combined a thorough knowledge of her subject with an easy and graceful style.
DODGE, RAYNAL. Born at Newburyport, Mass., September 9, 1844. Civil War veteran. Wounded at Port Hudson, June 28, 1863. A machinist by trade. A careful observer and student of nature, he discovered Aspidium simulatum at Follymill, Seabrook, N.H., in 1880. (Whittier's "My Playmate," verse 9.) He discovered also the hybrid Aspidium cristatum × Marginale. He published his little book, "Ferns and Fern Allies of New England," in 1896. Died October 20, 1918.
EATON, ALVAH AUGUSTUS. Born at Seabrook, N.H., November 20, 1865. Studied at the Putnam School in Newburyport, but was largely self-educated. He took up teaching for several years, spending three years in California. Returning East, he became a florist and began to write for various fern journals, giving special attention to the fern allies. He prepared the genera Equisetum and Isoetes for the seventh edition of "Gray's Manual." He proved the keenness of his observing powers by discovering several ferns new to the United States. Died at his home in North Easton, Mass., September 29, 1908.
WILLIAMSON, JOHN. Born in Abernathy, Scotland, about the year 1838. He came to Louisville, Ky., to live in 1866. A wood-carver by trade, he could work skillfully in wood or metal, and after a time established a brass foundry. His friend, George E. Davenport, writes of him: "He caught as by some divine gift or inspiration the innermost life and feelings of the wild flowers and ferns, and his marvelously accurate needle transfixed them with revivifying power on paper or metal." His "Ferns of Kentucky," issued in 1878, was the first handbook on ferns published in the United States. He died June 17, 1884, in the mountains of West Virginia, whither he had gone for his health.
AMERICAN FERN JOURNAL. 1910. The American Fern Society. (Annual subscription, $1.25.)
BELAIRS, NONA. Hardy Ferns. Smith, Elder and Co. London, 1865.
BRITISH FERN GAZETTE.
BRITTEN, JAMES. European Ferns. Colored Plates. Cassell & Co. London. Quarto.
BUTTERS, F.K. Athyrium. Study of the American Lady Ferns. Rhodora, September, 1917.
CAMPBELL, D.H. Structure and Development of the Mosses and Ferns. Macmillan & Co. 1905. Ed. 2.
CLUTE, WILLARD N. Our Ferns in Their Haunts. Frederick A. Stokes Co. New York, 1901.
Fern Collector's Guide. Frederick A. Stokes Co. New York, 1902.
The Fern Allies. Frederick A. Stokes Co. New York, 1905.
The Fern Bulletin. Founder and Editor. 20 vols. 1893-1912.
Combined with The American Botanist. Joliet, Ill. 1912.
CONARD, HENRY S. Structure and History of Hayscented Fern. Washington, 1908.
COOK, M.C. Fern-book for Everybody. E. Warne & Co. London.
DAVENPORT, GEO.E. Catalog of Davenport Herbarium, Massachusetts Horticultural Society. 1879. Numerous Monographs and Notes on New England ferns in Torrey Bulletin, Fern Bulletin, and Rhodora. The following monographs are in single booklets by Massachusetts Horticultural Society. Aspidium cristatum × marginale, Aspidium simulatum, Aspidium spinulosum and its Varieties, Botrychium ternatum and its Varieties, Notes on Botrychium simplex.
DODGE, RAYNAL. The Ferns and Fern Allies of New England--very small volume, now out of print. W.N. Clute & Co. 1904.
DRUERY, CHARLES T. British Ferns and Their Varieties. Routledge & Son. London.
EASTMAN, HELEN. New England Ferns and Their Common Allies. Houghton Mifflin & Co. Boston, 1904. Out of print.
EATON, DANIEL C. The Ferns of North America. 2 vols. 1879-80. S.E. Cassino, Salem. Drawings by J.H. Emerton and C.E. Faxon.
EATON, A.A. Specialist in Fern Allies. Prepared Equisetum and Isoetes for Gray's Manual, 7th ed. 1908.
GILBERT, BENJ.D. List of North American Pteridophytes. 1901. Utica, N.Y.
HERVEY, ALPHAEUS B. Wayside Flowers and Ferns. Page & Co. Boston, 1899.
HEMSLEY, ALFRED. Book of Fern Culture. John Lane. London, 1908.
HIBBARD, SHIRLEY. The Fern Garden. Groombridge & Sons. 5 Paternoster Row, London. 1869.
HOOKER, SIR W.J. Genera Filicum. Large 8vo. London, 1842. Contains fine plates which include all American genera. Costs about $25.
Species Filicum. 5 vols. 8vo. London, 1846-64. Vol. II contains seventeen and Vol. Ill contains two plates of American ferns with descriptions of more species. Cost about $50.
HOOKER, SIR W.J., & BAKER. Synopsis Filicum 2d ed. 1874. 8vo. Describes all ferns then known, including the American species. Has also figures illustrating each genus. Costs about $10.
LOWE, EDWARD J. Ferns British and Exotic. 9 vols. 8vo. Bell & Daldy. London, 1868. 550 plates, some very poor. Some American ferns are represented. "The descriptions," says John Robinson, "are worthless, and the synonymy is often incorrect."
MAXON, WILLIAM R. A List of Ferns and Fern Allies of North America, north of Mexico, etc. National Museum, 23:619-651. 1901.
Numerous Monographs and Notes on American Ferns in current magazines.
Studies of Tropical American Ferns. United States National Herbarium, 17:541+.
Pteridophyta (excepting Equisitaceæ and Isoetaceæ) of the northern United States, Canada and the British Possessions. In Britton and Brown, Illustrated Flora, etc., ed. 2, pp. 1-54. 1913. New York.
MEEHAN, THOMAS. Native Flowers and Ferns of the United States. Boston, 1878-9.
MOORE, THOMAS. Nature-printed British Ferns. 2 vols. London, 1859.
PARSONS, FRANCES T. How to Know the Ferns. Charles Scribner's Sons. New York, 1899.
PRATT, ANNE. The Ferns of Great Britain and Their Allies. F. Warne & Co. London. No date.
REDFIELD, JOHN. Geographical Distribution of the Ferns of North America. Torrey Bulletin, VI, 1-7. (1875).
RHODORA. Journal of the New England Botanical Club. January, 1899, to date.
ROBINSON, JOHN. Ferns in Their Homes and Ours. S.E. Cassino. Salem, 1878. Out of print.
SACHS, JULIUS. Text Book of Botany. (Translated.) Macmillan & Co. London. 8vo.
SLOSSON, MARGARET. How Ferns Grow. Henry Holt & Co. New York. 1906. Out of print.
SMALL, JOHN K. Ferns of Tropical Florida. New York, 1918.
SMITH, JOHN. Historia Filicum. London, 1875. Amply illustrated, reliable.
STEP, EDWARD. Wayside and Woodland Ferns. F. Warne & Co. London, 1908.
TIDESTROM, IVAR. Elysium Marianum. Washington, D.C.
UNDERWOOD, LUCIEN M. Our Native Ferns and Their Allies. Henry Holt & Co. Edition 6. 1900. Valuable. Out of print.
WATERS, CAMPBELL E. Ferns. Henry Holt & Co. 1903. Out of print. Scarce.
WEATHERBY, C.A. Changes in the Nomenclature of the Gray's Manual of Ferns. Important article in the Rhodora of October, 1919.
WILLIAMSON, JOHN. Ferns of Kentucky. J.P. Morton & Co. Louisville, Ky. 1878.
Fern Etchings. J.P. Morton & Co. 1879. Both out of print.
WOOLSON, GRACE A. Ferns and How to Grow Them. Doubleday, Page & Co. New York, 1909.
WRIGHT, MABEL O. Flowers and Ferns in Their Haunts. Macmillan & Co. New York,
1901. Poem
[Illustration: