XCIV. FILICES. 55D 
Sori circular. Noindusium . 4 (3). Potyropium alpestre. 
Sori circular, with a pao f shaped or almost peltate indusium attached DY 
point ° 
Sori rather oblong, with an indusium attached along one side 8. " ASPLENIUM, 
ee aa ovate or ovate-lanceolate. Indusia mee dy and persistent. 
7 (6). ASPIDIUM cr a a 
2 
Segments oblong-lanceolate . . ‘ ’ ° ° 
27 { Indusia conspicuous and persistent . . ah (8). Asprpium rigidum, 
Indusia small and often soon disappearing’ » 7 (7). Asprpium spinulosum. 
I. OPHIOGLOSSUM. ADDER’S TONGUE. 
Stem simple, bearing a single leaf-like barren frond in the lower part, 
and a simple terminal fruiting spike. Spore-cases rather large, closely 
sessile,,in two opposite rows, each opening by a transverse fissure. 
A genus of. very few species, but widely distributed over most parts of 
the globe. 
1. O. vulgatum, Linn. (fig. 1273). Common Adder’s-tongue.— 
Rootstock very small, but apparently perennial. Stem (combined stipes 
of the barren and fertile frond) solitary, from a few inches to near a foot 
high, with an ovate or oblong entire leaf-like barren frond, usually 2 to 3 
inches long, narrowed at the base into a shortly sheathing footstalk, and 
usually attached below the middle of thestem. Spike terminal, 3 to about 
an inch long, bearing on each side from about 15 to 25 closely sessile spore- 
cases. 
- In moist meadows, and pastures, throughout Europe, Asia, except the 
extreme north, North America, and apparently also in the southern hemi- 
sphere as well as within the tropics. Generally distributed over Britain, 
but more common in some parts of England and in Ireland than in the 
north of Scotland. Fr. summer. O. lusitanicum, Linn., is now believed 
to be a mere variety, only differing from the common form in its small 
size, the slender stems varying from 1 to 3 inches, the leaf or barren 
‘frond linear or lanceolate, narrowed into a stalk, and seldom above 1% 
inches long. It is usually to be found only in winter near the sea, along 
the west coast of Europe to Guernsey, but not on the main British Isles. 
IJ. BOTRYCHIUM. MOONWORT. 
Stem of Ophioglossum, but the leaf-like barren frond is divided, the 
terminal spike is branched, forming a panicle, and the spore-cases are 
globular, and, although sessile, quite distinct. 
A small genus, distributed over the temperate regions of the northern 
hemisphere, and more sparingly in the southern one. 
i, B. Lunaria, Sw. (fig. 1274). Common Moonwort.—Rootstock very 
small, bearing a single erect stem, 3 to 6 or 8 inches high, surrounded at 
the base by a few brown sheathing scales. The leaf or barren frond about 
the centre of the stem, 1 to 3 inches‘long, pinnate, with from 5 to 15 or even 
more obliquely fan-shaped or halfmoon-shaped segments, of a thick consis- 
tence, and entire or crenate. Panicle 1 to near 2 inches long, of a narrow 
pyramidal shape, the branches all turned towards one side. 
In dry, hilly, or mountain pastures, in northern and Arctic Europe, 
Asia, and America, in the mountains of central and southern Europe, and 
