95. MARSILEACEÆ.-96. LYCOPODIACEÆ. 417

Order XCV. MARSILEACEÆ.

Creeping plants with alternate erect leaves having a circinate vernation. Fructification consisting of globular nearly sessile coriaceous bodies with 3 or 4 cells and containing sacs including either other bodies that germinate or loose granules.

1. PILULARIA. Involucres solitary, nearly sessile, globose, coriaceous, 4-celled. Cells containing bodies of 2 kinds, granules and membranes containing minute grains.

1. PILULARIA Linn. Pillwort.

1. P. globulifera (L.).—E. B. 521. N.393.-Rhizoma slender elongated, creeping, producing leaves and roots at regular intervals. L. very slender, erect. Involucres (sporocarps) slightly stalked, axillary, nearly spherical, hairy.-Margins of ponds and lakes. P. Pepper grass. Pepper moss.

Order XCVI. LYCOPODIACEÆ.

Leafy plants with simple imbricated leaves; or stemless with erect subulate leaves. Fructification of axillary sessile thecæ with 2 or 3 valves and no ring, including minute powdery matter or sporules.

1. ISOETES.

of the leaves.
receptacles.

* Capsules not opening.

Fructification inclosed within the swollen base
Sporules of two kinds attached to filiform

** Capsules bursting.

2. LYCOPODIUM. Caps. 1-celled, 2-valved, containing powder; or 3-valved, containing 1-4 granules.

1. ISOETES Linn. Quillwort.

1. I. lacustris (L.); 1. subulate roundish-quadrangular with 4 longitudinal jointed tubes.-E. B. 1084. Hook. Lond. t. 131. N. 381. R. vii. t. 1.-Rhizoma a blunt tuber. L. slender, broad and flat at the base but elsewhere between cylindrical and quadrangular. There is still some doubt about the internal structure of the capsules.-Bottom of lakes and ponds in hilly districts. P.

2. LYCOPODIUM Linn.

* Caps. all 1-celled. Sporules like powder. LYCOPODIUM Koch. 1. L. clavatum (L.); 1. scattered incurved with a filamentous point, spikes stalked 2 or 3 together cylindrical, scales ovatetriangular membranous finely inciso-serrate.-E. B. 224. N. 353.

St. prostrate, many feet long. Spikes on long stalks, pale yellow. larly disposed in whorls.-Heaths. moss. Wolfs claw. W. B.

Branches short, ascending. Scales on the stalks irreguP. VII. VIII. Common Club

2. L. annotinum (L.); 1. scattered lanceolate mucronate serrulate, spikes sessile solitary terminal, scales roundish with an attenuated point membranous and jagged.—E. B. 1727. N. 361. ---St. prostrate, long. Branches rather long, erect, each year's growth marked by a spot where the leaves are adpressed. Spikes cylindrical, greenish-yellow, not persistent as supposed by Smith. -Stony mountains. Rare on Glyder Fawr, Caernarvonshire. Common in the Highlands. P. VIII. Welch clubmoss. E. S.

3. L. alpinum (L.); l. in four rows imbricated acute keeled entire, spikes sessile solitary terminal, scales ovate-lanceolate flat, branches erect clustered forked level-topped.—E. B. 234. N. 365.-St. prostrate, long. Fertile branches usually twice dichotomous, each division ending in a short cylindrical yellowishgreen spike rather thicker than the branch.-Elevated mountains. P. VIII. Savin-leaved Club-moss.

4. L. Selago (L.); l. in eight rows crowded uniform linearlanceolate acuminate, caps. not spiked but in the axils of the common leaves, st. erect forked level-topped.-E. B. 233. N.375. -St. short, erect or slightly decumbent, densely leafy. No separate spikes. At the extremity of the stems a few curious viviparous buds may usually be found; they are well illustrated by Mr. Newman (p. 378). Occasionally the stems in sheltered situations become much elongated.-Heaths, chiefly on mountains. P. VI. VIII. Fir Club-moss.

5. L. inundatum (L.); 1. scattered linear acute turned upwards, spikes terminal sessile leafy solitary upon short erect branches. -E. B. 239. N. 369. St. short, prostrate, rooting. Branches few, simple, short, erect, fertile.Boggy heaths. PVIII. IX. Marsh clubmoss. W.B.

** Caps. of two kinds. SELAGINELLA (Spring) Koch. 6. L. selaginoides (L.); 1. scattered lanceolate ciliated, spikes terminal solitary sessile leafy upon short erect branches.-E. B. 1148. N.371. Selaginella spinulosa Koch.—St. prostrate, much branched, rooting, slender. Flowering branches simple, short, erect. In addition to the 2-valved thecæ which occur in all our species, this plant produces others which are 3-valved and contain 2-4 large grains. Boggy spots chiefly in mountainous

places. P. VIII. Prickly clubmoss. W. 15.