Stem a perennial, creeping, horizontal rhizome, or sometimes erect and arborescent. Fronds (fruit-bearing leaves) variously divided, rarely entire, with forked veins, and mostly circinate vernation. Fructification occupying the back or margin of the fronds, arising from the veins. Sporangia (spore-cases) of one kind, scattered or clustered in sori, 1-celled, containing numerous, minute spores. An-theridia and pistillidia formed after germination, on the young plant. (See figs. 491 - 501.)

Genera 200, species 2000. - A large and interesting order of flowerless plants, distinguished for their elegant, plume-like foliage. They are usually a few inches to a few feet high, but some of the tropical species, as the Cyatheae of both Indies, are 15 - 25 feet high, Vicing with the palms in size and beauty.

Properties. - Generally mucilaginous and mildly astringent, hence considered pectoral. Aspidium and Pteris are anthelmintic. Os-munda regalia has been successfully administered for the rickets.

Observation. - The fructification of the ferns., with its various appendages, is too minute to be well observed by the naked eye; but an examination of it with the aid of a good lens cannot fail to be interesting and satisfactory.

739 Polypodium vulgare. 710 Frond

739 Polypodium vulgare. 710 Frond. 741 Lobe of the frond enlarged, showing the sori. 742 One of the sori enlarged, showing the sporangia. 743 One sporange further magnified, bursting and discharging the spores. 744 Sorns of Aspidium marginale covered with the inda-sium. 745 Same, side view.

Suborders And Genera

§ Frond cauline, solitary, straight in vernation. Stem erect (a)

§ Fronds cauline, several, palmate (or radical and filiform), (b)

§ Fronds all radical, clustered (never filiform), circinate in vernation. (2)

2 Sporangia spiked or panicled, naked (not involved in revolute fronds). (c)

2 Sporangia on the back of the fronds, - but involved in the revolute segm............

Nos. 8, 10

- not involved; segments flat, (c)

SUBORDER I. OPHIOGLOSSEae. (Sporangia naked, smooth, cartilaginous, 2-valvcd; no ring.)

a Fructification spicate. Frond entire, reticulate-veined............

OPHOGLOSSUM.

1

a Fructification paniculate. Frond divided, fork-vained...................

BOTRYCHIUM.

2

SUBORDER II. OSMUNDEae. (Sporangia reticulate-roughened, papery, 2-valved, with no ring, spicate or paniculate.) - b Fronds palmate. Climbing..............................

Lygodicm.

3

- b Fronds filiform. Erect....................................

SCHIZae.

4

- b Fronds 1 - 2-pinnate..................................

OSMUNDA.

5

Suborder III. POLYPODINEae. (Sporangia minute, on the back of the frond, valveless, torn open by the elastic ring which encircles it vertically.)

C Sporangia scattered singly all over the surface (not in sori), naked.............

ACROSTICUM.

6

C Sporangia collected in dots (sori) springing from the Veins, (d)

d Fruit-dots naked, having no indusium (special covering), (e)

e Fronds all alike, flat. Fruit-dots orbicular..................................................

POLYPODIUM.

7

e Fronds sterile and fertile very different; the fertile spike-like.....

STRUTHIOPTERlS

8

d Fruit-dots invested with special coverings (indusia). (g)

g Fruit-dots marginal; indusium a narrow, reflected edge, of frond, (h)

h Indusium continous all aroundthe segment...........................................

PTERIS.

9

h Indusium from the apex of the segm. - Midvein central......

CHEILANTHES.

10

- Midvein lateral or 0...

ADIANTUM.

11

h Indusium a reflected tooth at the sinus between the segments

DlCKSONIA.

12

g Fruit-dots dorsal, oblong or linear, parallel with the midvein.....

WOODWAEDIA.

13

g Fruit-dots dorsal, oblong or linear, transverse to the midvein. (k)

k Indusia single, regularly arranged in 2 rows...........................

ASPLENIUM.

14

k Indusia single, scattered irregularly, placed angularly.....

ANTIGRAMMA.

15

k Indusia double, regularly arranged. Frond simple......................

SCOLOPENDRIUM.

16

g Fruit-dots dorsal, orbicnlar. (o)

o Indusium cup-shaped, fixed beneath all around the sorus...................

WOODSIA.

17

o Indusium hood-shaped, fixed at the base and 2 sides..........................

CISTOPTERIS.

18

o Indusium peltate or renif in, - all involved in the berry-like segm.

Onoclea.

19

- all superficial on the flat segm..........

ASPIDIUM.

20

1. OPHIOGLOS'SUM, L. Adder's Tongue. (Gr.Suborders And Genera 2743 a serpent,

Suborders And Genera 2744 tongue.) Sporangia roundish, depressed, opening transversely, arranged in two rows along the margins of the fertile frond which is contracted into a linear spike; indusium none, veins reticulated.

1 O. vulgatum L. Frond simple, oblong-ovate, obtuse, reticulations elongated; spike cauline, root of thick spreading fibres. - A curious little plant in low grounds. Fronds solitary, 2 - 3' long, 2/3 as wide, amplexicaul, entire, smooth, without a midvein, situated upon the stem or stipe a little below the middle. Stipe 6 - 10' high, terminating in a lance-linear, compressed spike, 1 - 2' long, with the fruit arranged in 2, close, marginal ranks. Sporangia opening outwards and horizontally, becoming lunate, distinct, straw-colored. Vernation straight, not circinate. June.

2 O. bulbosum L. Frond simple, ovate or orbiculate, or reniform, subcordate, nearly or quite radical, obtuse; reticulations short, spike oauline; root a subglolous bulb. - Wet pine barrens, N. J. (Pursh) to Ga. and La. Sts. about 3' high, often 2 from the same bulb, spike short, oblong (4 to 8"). Lvs. 2 or 3, one of them cauline. Bulbs, 3 to 6" diam.

2. BOTRYCHIUM, Swartz. Moonwort, Grape Fern. (Gr.Suborders And Genera 2745 a cluster of grapes; from the resemblance of the fructification.) Sporangia subglobous, 1-celled, 2-valved, distinct, coriaceous, smooth, adnate to the compound rachis of a racemous panicle; valves opening transversely.

§ Frond ternately divided, situated near the base of the stipe or stem................................

Nos.

1, 2

§ Frond pinnately divided, situated at or above the middle of the stem.............................

Nos.

3, 4

1 B. lunarioides Swartz. Scape bearing the frond near the base; frond in 3 bipinnatifid divisions; segments obliquely lanceolate, crenulate; spikes bipinnate. - Native of shady woods and pastures. Frond almost radical, of a triangular outline, 3 - 5' long and wide, of a stouter texture than No. 4, distinctly petiolate. Scape thick, 8 - 12' high, bearing a tawny, compound panicle 2 - 4' in length, composed of numerous little 2-ranked spikes. Aug. (B. obliquum Muhl. B fumarioides Willd.)

β. dissectum. Frond near the base of the scape, more numerously dissected, almost tripinnatifid. (B. dissectum Willd.)

2 B. simplex Hitchcock. Frond ternate, borne near half way up the stalk; lfts. cuneate-obovate, subentire or incised, unequal; spike compound, interrupted, unilateral; capsules sessile, yellow. - Dry hilly pastures, Vt. and Mass. Stipe or scape 3 to 6' high. Closely resembles B. lunaria of Eur. Frond varies from simply ternate to ternate-pinnatifld. Jn.

3 B. neglectum. Meriden Moonwort. Frond simply pinnate, with oblong-ovate or oval, incised leaflets, and borne near the summit of the scape; capsules pedicellate, subsolitary, in an oblong panicle. - Rocky woods, N. H. (Meriden!) Allied rather to the next than to No. 1. St 5 to 8' high. Frond 9 to 20" long, half as wide. Lfts. 3 or 4 pairs. Pan. often larger than the fronds. Caps, brownish, on very short, thick stipes. July.

4 B. Virginicum L. Rattlesnake Fern. Stipe with a single frond in the middle; frond twice and thrice pinnate, the lowest pair of pinnae springing from the base; ultimate segments obtuse, somewhat 3-toothed; spikes decompound; plant subpilous. - A beautiful fern, the largest of its genus, in low woods. Stipe or scape 1 - 2f high, bearing the frond about half-way up. This is apparently ternate, the lower pair of divisions arising from the base. It is almost tripinnate, the ultimate segments being decurrent and more or le33 confluent at base, with 3 - 5 cut serratures. Panicle terminal, 3 - 6' long, reddish-tawny. June, July.

3. LYGO'DIUM Swartz. Climbing Fern. (Gr.Suborders And Genera 2746 flexible, slender; from the habit.) Sporangia sessile, arranged in 2-ranked spikelets issuing from the margin of the contracted frond, opening on the inner side from the base to the summit; indusium a scale-like veil covering each sporange. (Fig. 109.)

L. palmatum Sw. Stem flexuous, climbing; fronds conjugate, palmate, 5-lobed, lobes entire, obtus9; spikelets oblong-linear, from the upper fronds, which are divided and contracted into a compound spike. - This is one of the few ferns with climbing stems, and the only one found in the U. S., Mass. to Ky. and S. States, rare. Plant of a slender and delicate structure, smooth. Stem 3 - 4f long. Stipes alternate on the stem, forked, supporting a pair of fronds which are palmately divided into 5 - 9 segments. Fertile fronds terminal, numerously subdivided into linear-oblong segments or spikelets, with the fruit in 2 rows on the back. July.