The Fern Lover's Companion Part 3

_Scolopendrium_.

[Ill.u.s.tration]

Shorter and irregularly scattered on the under side of the frond, some parallel to the midrib, others oblique to it, and often in pairs or joined at the ends; blade tapering to a slender tip. Walking Fern. _Camptosorus_.

[Ill.u.s.tration]

Short, straight, mostly oblique to the midrib. Indusium rather narrow, opening toward the midrib, fronds lobed or variously divided. Spleenworts.

_Asplenium_.

[Ill.u.s.tration]

Short, indusium usually more or less curved and frequently crossing a vein.

The large spleenworts including Lady Fern. _Athyrium_.

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 (Polypodiaceae)_ with sixty species and several chief varieties. Then follow the _flowering ferns (Osmundaceae)_ with three species; the _curly gra.s.s_ and _climbing ferns (Schizaeaceae)_ with two species; the _adder's tongue_ and _grape ferns (Ophioglossaceae)_ with seven species; and the _filmy ferns (Hymenophyllaceae)_ 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.

[Ill.u.s.tration: Fig. 1]

[Ill.u.s.tration: Fig. 2]

[Ill.u.s.tration: Fig. 3]

[Ill.u.s.tration: Fig. 4]

1. The Fern Family proper (_Polypodiaceae_) has the spore cases stalked and bound by a vertical, elastic ring (Fig. 1). The cl.u.s.ters 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 (_LyG.o.dium, Schizaea_) 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 (_Ophioglossum, Botrchium_) has simple spore cases without a ring, and discharges its spores through a transverse slit (Fig. 6).

5. The Filmy Fern Family (_Trichomanes_) 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).

[Ill.u.s.tration: Fig. 5]

[Ill.u.s.tration: Fig. 6]

[Ill.u.s.tration: Fig. 7]

THE FERN FAMILY PROPER OR REAL FERNS

_POLYPODIaCEae_

Green, leafy plants whose spores are borne in spore-cases (sporangia), which are collected in dots or cl.u.s.ters (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.

[Ill.u.s.tration: Common Polypody. _Polypodium vulgare_]

Common everywhere on cliffs, usually in half shade, and may at times spring out of decaying logs or the trunks of trees. As the jointed stipes, harking back to some ancient mode of fern growth, fall away from the rootstocks after their year of greenness, they leave behind a scar as in Solomon's seal. The polypody is a gregarious plant. By intertwining its roots the fronds cling together in "cheerful community," and a friendly eye discovers their beauty a long way off. August. Abounds in every clime, including Europe and j.a.pan.

In transplanting, sections should be cut, not pulled from the matted ma.s.s.

Var. _cambric.u.m_ has segments broader and more or less strongly toothed.

Var. _cristatum_ has the segments forked at the ends.

Several other forms are also found.

[Ill.u.s.tration: Fruited Frond]

[Ill.u.s.tration: The Common Polypody. _Polypodium vulgare_ (Photographed by Miles Greenwood, Melrose, Ma.s.s.)]

(2) GRAY OR h.o.a.rY POLYPODY

_Polypodium incanum. P. polypodiides_

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

[Ill.u.s.tration: Gray or h.o.a.ry 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.