[Illustration: Fig. 4]

SPORÀNGIA AND FRUIT DOTS

Fern spores are formed in little sacs known as spore-cases or sporángia (Fig. 4). They are usually clustered in dots or lines on the back or margin of a frond, either on or at the end of a small vein, or in spike-like racemes on separate stalks. Sori (singular sorus, a heap), or fruit dots may be naked as in the polypody, but are usually covered with a thin, delicate membrane, known as the indusium (Greek, a dress, or mantle). The family or genus of a fern is often determined by the shape of its indusium; e.g., the indusium of the woodsias is star-shaped; of the Dicksonias, cup-shaped; of the aspleniums, linear; of the wood ferns, kidney-shaped, etc.

In many ferns the sporangia are surrounded in whole or in part by a vertical, elastic ring (annulus) reminding one of a small, brown worm closely coiled (Fig. 4). As the spores mature, the ring contracts and bursts with considerable force, scattering the spores. The spores of the different genera mature at different times from May to September. A good time to collect ferns is just before the fruiting season. (For times of fruiting see individual descriptions or chronological chart on page 220.)

HELPFUL HINTS

The following hints may be helpful to the young collector:

1. A good lens with needles for dissecting is very helpful in examining the sori, veins, glands, etc., as an accurate knowledge of any one of these items may aid in identifying a given specimen. Bausch and Lomb make a convenient two-bladed pocket glass for about two dollars.[1]

[Footnote 1: In the linen tester here figured (cost $1.50) the lens is mounted in a brass frame which holds it in position, enabling the dissector to use both hands. A tripod lens will also be found cheap and serviceable.]

[Illustration: Linen Tester]

2. Do not exterminate or weaken a fern colony by taking more plants than it can spare. In small colonies of rare ferns take a few and leave the rest to grow. It is decidedly ill-bred to rob a locality of its precious plants. Pick your fern leaf down close to the root-stock, including a portion of that also, if it can be spared. Place your fronds between newspaper sheets and lay "dryers" over them (blotting paper or other absorbent paper). Cover with a board or slat frame, and lay on this a weight of several pounds, leaving it for twenty-four hours; if the specimens are not then cured, change the dryers. Mount the prepared specimens on white mounting sheets. The regulation size is 16-1/2 by 11-1/2 inches. The labels are usually 3-3/4 by 1-3/4 inches. A sample will suggest the proper inscription.

Place the label at the lower right-hand corner of the sheet, which is now ready to be laid in the genus cover, usually of manila paper 16-1/2 by 12 inches. It is well to jot down important memoranda at the time of collecting. This is the method in use at the Gray Herbarium in Cambridge. It can, of course, be modified to suit one's own taste or convenience. The young collector can begin by simply pressing his specimens between the leaves of a book, the older and coarser the better; and he can mount them in a blank book designed for the purpose, or if he has only a common blank book, he can cut out some of the leaves, alternately with others left in place, as is often done with a scrap book, that when the book is full it may not be crowded at the back. Or he can use sheets of blank paper of any uniform size and mount the specimens on these with gummed strips, and then group them, placing those of the same genus together. Such an extemporized herbarium, though crude, will serve for a beginning, while stimulating his interest, and advancing his knowledge of the ferns. Let him collect, press, and mount as many varieties as possible, giving the name with date and place of collecting, etc. Such a first attempt may be kept as a reminder of pleasant hours spent in learning the rudiments of a delightful study.

We cannot insist too strongly upon the necessity of handling and studying the living plant. Every student needs to observe for himself the haunts, habits, and structure of real ferns. We would say to the young student, while familiarizing yourself with the English names of the ferns, do not neglect the scientific names, which often hold the key to their meaning. Repeat over and over the name of each genus in soliloquy and in conversation until your mind instantly associates each fern with its family name--"Adiantum," "Polystichum," "Asplenium," and all the rest. Fix them in the memory for a permanent asset. With hard study and growing knowledge will come growing attachment. How our great expert, Mr. Davenport, loved the ferns! He would handle them with gentle touch, fondly stroke their leaves, and devoutly study their structure, as if inspired by the All-wise Interpreter.

KEY TO THE GENERA

This key, in illustrating each genus, follows the method of Clute in "Our Ferns in Their Haunts," but substitutes other and larger specimens. Five of these are from Waters' "Ferns" by permission of Henry Holt & Co.

As the indusium, which often determines the name of a fern, is apt in some species to wither early, it is important to secure for study not only a fertile frond, but one in as good condition as possible. For convenience the ferns may be considered in two classes.

I

THOSE WHICH HAVE THE FRUITING PORTION IN GREENISH, BERRY-LIKE STRUCTURES AND NOT ON THE BACK OF FRONDS

A. FRUITING FRONDS WHOLLY FERTILE
(Fertile and sterile fronds entirely unlike)

B. FRUITING FRONDS PARTLY STERILE

II

THOSE WHICH HAVE THE FRUITING PORTION ON THE BACK OR MARGIN OF FRONDS

A. INDUSIUM WANTING

B. INDUSIUM PRESENT

DESCRIPTIVE TEXT OF THE FERNS

In this manual our native ferns are grouped scientifically under five distinct families. By far the largest of these groups, and the first to be treated, is that of the real ferns (Polypodiàceæ) with sixty species and several chief varieties. Then follow the flowering ferns (Osmundàceæ) with three species; the curly grass and climbing ferns (Schizæàceæ) with two species; the adder's tongue and grape ferns (Ophioglossàceæ) with seven species; and the filmy ferns (Hymenophyllàceæ) with one species.

Corresponding with these five families, the sporangia or spore cases of ferns have five quite distinct forms on which the families are founded.

Fig. 1-4: Sporangia of the Five Families]

1. The Fern Family proper (Polypodiàceæ) has the spore cases stalked and bound by a vertical, elastic ring (Fig. 1). The clusters of fruit-dots containing the spore cases may be open and naked as in polypody (Fig. 2), or covered by an indusium, as in the shield ferns (Fig. 3).

2. The Royal Fern Family (Osmunda) has the spore cases stalked with only a rudimentary ring on one side, which opens longitudinally (Fig. 4).

3. The Climbing Fern Family (Lygodium, Schizæa) has the spore cases sessile in rows; they are small, nut-like bodies with the elastic ring around the upper portion (Fig. 5).[1]

[Footnote 1: These figures are enlarged.]

4. The Adder's Tongue Family (Ophioglóssum, Botrýchium) has simple spore cases without a ring, and discharges its spores through a transverse slit (Fig. 6).

5. The Filmy Fern Family (Trichómanes) has the spore cases along a bristle-like receptacle and surrounded by an urn-shaped, slightly two-lipped involucre; ring transverse and opening vertically (Fig. 7).

Fig. 5-7: Indusium

THE FERN FAMILY PROPER OR REAL FERNS

POLYPODIÀCEÆ

Green, leafy plants whose spores are borne in spore-cases (sporangia), which are collected in dots or clusters (fruit-dots or sori) on the back of the frond or form lines along the edge of its divisions. Sporangia surrounded by vertical, elastic rings bursting transversely and scattering the spores. Fruit-dots (sori) often covered, at least when young, by a membrane called the indusium. Spores brown.

THE POLYPODIES

1. POLYPODY. Polypodium

(From the Greek meaning many-footed, alluding to the branching rootstocks.)

Simple ferns with stipes articulated to the creeping rootstocks, which are covered with brown, chaffy scales. Fruit-dots round, naked, arranged on the back of the frond in one or more rows each side of the midrib. Sporangia pedicelled, provided with a vertical ring which bursts transversely. A large genus with about 350 species, widely distributed, mostly in tropical regions.

(1) COMMON POLYPODY. Polypodium vulgare

Fronds somewhat leathery in texture, evergreen, four to ten inches tall, smooth, oblong, and nearly pinnate. The large fruit-dots nearly midway between the midrib and the margin, but nearer the margin.

Common Polypody. Polypodium vulgare

(2) GRAY OR HOARY POLYPODY

Polypodium incànum. P. polypodiòides

Fronds oblong, two to seven inches long, deeply pinnátifid, gray and scurfy underneath with peltate scales having a dark center. Fruit-dots rather small, near the margin and obscured by the chaff.

Gray or Hoary Polypody. Polypodium incanum

In appearance the gray polypody is much like the common species, as the Greek ending oides (like) implies. In Florida and neighboring states it often grows on trees; farther north mostly on rocks. Reported as far north as Staten Island. It is one of the "resurrection" ferns, reviving quickly by moisture after seeming to be dead from long drouth. July to September. Widely distributed in tropical America. Often called Tree-Polypody.

THE BRACKEN GROUP

Sporangia near or on the margin of the segments, the reflexed portions of which serve as indusia.

1. BRACKEN OR BRAKE

Ptèris aquilina. PTERÍDIUM LATIÚSCULUM[1]

[Footnote 1: The use of small capitals in the scientific names indicates in part the newer nomenclature which many botanists are inclined to adopt.]

Fronds broadly triangular, ternate, one to three feet high or more, the widely spreading branches twice pinnate, the lower pinnules more or less pinnátifid. Sporangia borne in a continuous line along the lower margin of the ultimate divisions whose reflexed edges form the indusium. (Greek, pteron, a wing, the feathery fronds suggesting the wings of a bird.)

Common Bracken or Brake, a Sterile Frond. Pteris aquilina (Providence County, R.I.)

A Fertile Frond of Common Bracken. Pteris aquilina (Suffolk County, Mass.)

The outlines of the young bracken resemble the little oak fern. It flourishes in thickets and open pastures, often with poor soil and scant shade. It is found in all parts of the world, and is said to be the most common of all our North American ferns. In a cross section of the mature stipe superstition sees "the devil's hoof" and "King Charles in the oak," and any one may see or think he sees the outlines of an oak tree. It was the bracken, or eagle fern, as some call it, which was supposed to bear the mysterious "fern seed," but only on midsummer eve (St. John's eve).

This enabled its possessor to walk invisible.

The word brake or bracken is one of the many plant names from which some of our English surnames are derived, as Brack, Breck, Brackenridge, etc., and fern (meaning the bracken) is seen in Fern, Fearns, Fernham, Fernel, Fernside, Farnsworth, etc. Also, in names of places as Ferney, Ferndale, Fernwood, and others. Although the bracken is coarse and common, it makes a desirable background for rockeries, or other fern masses. The young ferns should be transplanted in early spring with as much of the long, running rootstock as possible.

Var. pseudocaudàta has longer, narrower and more distant pinnules, and is a common southern form.

Var. pseudocaudata

2. MAIDENHAIR. Adiantum

Ferns with much divided leaves and short, marginal sori borne at the ends of free-forking veins, on the under side of the reflexed and altered portion of the pinnules, which serves as an indusium. Stipes and branches of the leaves very slender and polished.

(Greek, unwetted, because drops of water roll off without wetting the leaves.)

(1) COMMON MAIDENHAIR. Adiantum pedatum

A graceful fern of shady glen and rocky woodland, nine to eighteen inches high, the black, shining stalks forked at the top into two equal, recurved branches, the pinnæ all springing from the upper side. Pinnules triangular-oblong, bearing short sori on their inwardly reflexed margins which form the indusium.

[Illustration: A Spray of Maidenhair]

[Illustration: Fruiting Pinnæ of Maidenhair]

The maidenhair has a superficial resemblance to the meadow rue, which also sheds water, but it may be known at once by its black, shining stalks with their divisions all borne on one side. It is indeed a most delicate fern, known and admired by every one. The term maidenhair may have been suggested by the black, wiry roots growing from the slender rootstock, or by the dark, polished stems, or, as Clute explains it, "because the black roots, like hair, were supposed, according to the 'doctrine of signatures' to be good for falling hair, and the plant was actually used in the 'syrup of capillaire'[A] (Am. Botanist, November, 1921). While the maidenhair is not very common, it is widely distributed, being found throughout our section, westward to California, and northward to the British Provinces.

"Though the maidenhair has a wide range, and grows abundantly in many localities, it possesses a quality of aloofness which adds to its charm. Its chosen haunts are dim, moist hollows in the woods, or shaded hillsides sloping to the river. In such retreats you find the feathery fronds tremulous on their glistening stalks, and in their neighborhood you find, also, the very spirit of the woods."
MRS. PARSONS.

[Footnote A: It may be stated that capillaire syrup besides the use here indicated was highly esteemed as a pectoral for the relief of difficult breathing.]

[Illustration: Common Maidenhair. Adiantum pedatum (Reading, Mass., Kingman)]

[Illustration: Alpine Maidenhair. Adiantum pedatum, Var. aleuticum (Fernald and Collins, Gaspé County, Quebec, 1906) (From the Gray Herbarium)]

The fern is not hard to cultivate if allowed sufficient moisture and shade. Along with the ostrich fern it makes a most excellent combination in a fern border.

Var. ALEUTICUM, or Alpine Maidenhair. A beautiful northern form especially abundant on the high tableland of the Gaspé Peninsula, Quebec, where it is said to cover hundreds of acres. In the east it is often dwarfed--six to ten inches high, growing in tufts with stout rootstocks, having the pinnules finely toothed instead of rounded and the indusia often lunate, rarely twice as long as broad. (Fernald in Rhodora, November, 1905.) Also found in northern Vermont, and to the northwestward.

(2) THE VENUS-HAIR FERN. Adiantum Capíllus-Veneris

Fronds with a continuous main rachis, ovate-lanceolate, twice pinnate below. Pinnules, fan-shaped on slender, black stalks, long, deeply and irregularly incised. Veins extending from the base of the pinnules like the ribs of a fan.

[Illustration: Venus Hair Fern. Adiantum Capillus-Veneris]

While our common maidenhair is a northern fern, the Venus-hair Fern is confined to the southern states. It is rarely found as far north as Virginia, where it meets, but scarcely overlaps its sister fern. The medicinal properties of Adiantum pedatum were earlier ascribed to the more southern species, which is common in Great Britain, but, like many another old remedy, "the syrup of capillaire" is long since defunct.

3. CLIFF BRAKES. Pellàea

Sporangia borne on the upper part of the free veins inside the margins, in dot-like masses, but may run together, as in the continuous fruiting line of the bracken. Indusium formed of the reflexed margins of the fertile segments which are more or less membranous. (Pellæa, from the Greek pellos, meaning dusky, in allusion to the dark stipes.)

(1) PURPLE CLIFF BRAKE. Pellæa atropurpùrea

Stipes dark purple or reddish-brown, polished and decidedly hairy and harsh to the touch, at least on one side. Fronds coriaceous, pale, simply pinnate, or bipinnate below; 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. Basal scales extending into long, slender tips, colorless or yellow.

[Illustration: Purple Cliff Brake. Pellæa atropurpurea]

Another name is "the winter brake," as its fronds remain green throughout the winter, especially in its more southern ranges. It grows on rocky ledges with a preference for limestone, and often in full sun. In large and mature fronds its pinnæ are apt to be extremely irregular. While its stipes are purplish, its leaves are bluish-green, and its scales light-brown or yellow. Strange to say, this brake of the cliffs thrives in cultivation. Woolson says of it, "This fern is interesting and valuable. It is not only beautiful in design, but unique in color, a dark blue-green emphasizing all the varying tints about it--a first-class fern for indoor winter cultivation. It is a rapid grower, flourishing but a few feet from coal fire or radiator, in a north or south window. It quickly forgives neglect, and if allowed to dry up out of doors or indoors, recovers in due time when put in a moist atmosphere. It makes but one imperative demand, and that is the privilege of standing still. Overzealous culturists usually like to turn things around, but revolving cliffs are not in the natural order of things. The slender black stipes are very susceptible to changes of light and warped and twisted fronds result."

Dry, calcareous rocks, southern New England and westward. Rare. Var. cristata has forked pinnæ somewhat crowded toward the summit of the frond. Missouri.

(2) SMOOTH CLIFF BRAKE

Pellàea glabella. Pellàea atropurpùrea, var. Bushii

Naked with a few, scattered, spreading hairs, smooth surface and dark polished stipes. Rhizome short with membranous, orange or brown scales having a few bluntish teeth on each edge. Pinnæ sub-opposite, divergent, narrowly oblong, obtuse; base truncate, cordate or clasping, occasionally auricled; lower pinnæ often with orbicular or cordate pinnules. Sterile pinnæ broader, bluish or greenish glaucous above, often crowded to overlapping. The smooth cliff brake has a decidedly northern range, growing from northern Vermont to Missouri, and northwestward, but found rarely, if at all, in southern New England.

[Illustration: Dense Cliff Brake. Cryptogramma densa (From Waters's "Ferns," Henry Holt & Co.)]

(3) DENSE CLIFF BRAKE

Cryptográmma densa. Pellaèa densa

Modern botanists are inclined to place the dense cliff brake and the slender cliff brake under the genus Cryptográmma, which is so nearly like Pellaea that one hesitates to choose between them. The word Cryptográmma means in Greek a hidden line, alluding to the line of sporangia hidden beneath the reflexed margin.

The dense cliff brake may be described as follows:

Stipes three to nine inches tall, blades one to three inches, triangular-ovate, pinnate at the summit, and tripinnate below. Segments linear, sharp-pointed, mostly fertile, having the margins entire and recurved, giving the sori the appearance of half-open pods. Sterile fronds sharply serrate. Stipes in dense tufts ("densa") slender, wiry, light-brown.

This rare little fern is a northern species and springs from tiny crevices in rocks, preferring limestone. Like many other rock-loving species, it produces spores in abundance, having no other effective means of spreading, and its fertile fronds are much more numerous than the sterile ones, and begin to fruit when very small. Gaspé and Mt. Albert in the Province of Quebec, Grey County, Ontario, and in the far west.

(4) SLENDER CLIFF BRAKE

Cryptográmma Stellèri. Pellaèa grácilis

Fronds (including stipes) three to six inches long, thin and slender with few pinnæ. The lower pinnæ pinnately parted into three to five divisions, those of the fertile fronds oblong or linear-oblong; those of the sterile, obovate or ovate, crenulate, decurrent at the base. Confined to limestone rocks. Quebec and New Brunswick, to Vermont, Connecticut, Pennsylvania, and to the northwest.

[Illustration: Slender Cliff Brake. Cryptogramma Stelleri]

We have collected this dainty and attractive little fern on the limestone cliffs of Mt. Horr, near Willoughby Lake, Vt. It grew in a rocky grotto whose sides were kept moist by dripping water. How we liked to linger near its charming abode high on the cliff! And we liked also to speak of it by its pleasing, simple name, "Pellæa gracilis," now changed for scientific reasons, but we still like the old name better.

(5) THE ROCK BRAKE. PARSLEY FERN

Cryptográmma acrostichòides

Sterile and fertile fronds very dissimilar; segments of the fertile, linear and pod-like; of the sterile, ovate-oblong, obtuse, and toothed. The plants spring from crevices of rocks and are from six to eight inches high. Stipes of the fertile fronds are about twice as long as the sterile, making two tiers of fronds.

[Illustration: Parsley Fern or Rock Brake. Cryptogramma acrostichoides (California and Oregon) (Herbarium of Geo. E. Davenport)]

The parsley fern is the typical species of the genus Cryptográmma. The indusium is formed of the altered margin of the pinnule, at first reflexed to the midrib, giving it a pod-like appearance, but at length opening out flat and exposing the sporangia. Clute, speaking of this fern as "the rock brake," calls it a border species, as its home is in the far north--Arctic America to Lake Huron, Lake Superior, Colorado and California.

4. LIP FERNS. Cheilánthes

Mostly small southern ferns growing on rocks, pubescent or tomentose with much divided leaves. Sori at the end of the veins at first small and roundish, but afterwards more or less confluent. The indusium whitish and sometimes herbaceous, formed of the reflexed margin of the lobes or of the whole pinnule. Veins free, but often obscure. Most of the ferns of this genus grow in dry, exposed situations, where rain is sometimes absent for weeks and months. For this reason they protect themselves by a covering of hairs, scales or wool, which hinders the evaporation of water from the plant by holding a layer of more or less saturated air near the surface of the frond. (In Greek the word means lip flower, alluding to the lip-like indusia.)

(1) ALABAMA LIP FERN. Cheilánthes alabaménsis

Fronds smooth, two to ten inches long, lanceolate, bipinnate. Pinnæ numerous, oblong-lanceolate, the lower usually smaller than those above. Pinnules triangular-oblong, mostly acute, often auricular or lobed at the base. Indusia pale, membranous and continuous except between the lobes. Stipes black, slender and tomentose at the base.

[Illustration: Alabama Lip Fern. Cheilanthes alabamensis (From Waters's "Ferns," Henry Holt & Co.)]

This species of lip fern may be distinguished from all the others within our limits by its smooth pinnæ. On rocks--mountains of Virginia to Kentucky, and Alabama, and westward to Arizona.

(2) HAIRY LIP FERN. Cheilánthes lanòsa, C. véstita

[Illustration: Hairy Lip Fern]

Fronds twice pinnate, lanceolate with oblong, pinnátifid pinnules; seven to fifteen inches tall, slender and rough with rusty, jointed hairs. Pinnæ triangular-ovate, usually distant, the ends of the rounded lobes reflexed and forming separate involucres which are pushed back by the ripening sporangia.

This species like the other lip ferns is fond of rocks, springing from clefts and ledges. While hairy it is much less tomentose than the two following species. Unlike most of the rock-loving ferns this species is not partial to limestone, but grows on other rocks as well. It has been found as far north as New Haven, Conn., also near New York, and in New Jersey, Georgia, and westward to Wyoming and southward.

(3) WOOLLY LIP FERN. Cheilánthes tomentòsa

Fronds eight to eighteen inches long, lanceolate-oblong, tripinnate. Pinnæ and pinnules ovate-oblong, densely woolly especially beneath, with slender, whitish, obscurely jointed hairs. Of the ultimate segments the terminal one is twice as long as the others. Pinnules distant, the reflexed, narrow margin forming a continuous, membranous indusium. Stipe stout, dark brown, densely woolly.

By donning its thick coat of wool this species is prepared to grow in the most exposed situations of the arid southwest. It is said to be the "rarest, tallest and handsomest of the lip ferns."

Mountains of Virginia and Kentucky to Georgia, and west to Missouri, Texas and Arizona.

(4) SLENDER LIP FERN

Cheilánthes Féei, C. lanuginòsa

Stipes densely tufted, slender, at first hairy, dark brown, shining. Fronds three to eight inches long, ovate-lanceolate, with thickish, distinctly articulated hairs, twice or thrice pinnate. Pinnæ ovate, the lowest deltoid. Pinnules divided into minute, densely crowded segments, the herbaceous margin recurved and forming an almost continuous indusium.

[Illustration: Slender Lip Fern]

The slender lip fern, known also as Fée's fern, is much the smallest of the lip ferns, averaging, Clute tells us, "but two inches high." This is only one-third as tall as the woolly lip fern and need not be mistaken for it. The fronds form tangled mats difficult to unravel. It grows on dry rocks and cliffs--Illinois and Minnesota to British Columbia, and south to Texas, New Mexico and Arizona.