Lycopodium. | XC. LYCOPODIACER. 547 
XCI. SELAGINELLACEZ, 
Prostrate herbs, with minute imbricating leaves often of two 
forms, or stemless water-plants with slender leaves. Spore- 
cases of two forms; in the former case in the axils of the scales 
of a spike, in the latter at the bases of the leaves. Spores of 
two forms. 7 
[This Order has only recently been established. It includes one of the 
‘Lycopodiums of former editions of this work together with the genus Isoefes, 
with which it agrees in the most important character of having two kinds 
of spores, thus differing from Lycopodiacea. | 
A prostrate moss-like plant. Spore-cases in the bracts of a ter- 
minal spike . : : : ; - : : - ; ° 
Stemless plants with long subulate leaves. Spore-cases in the 
dilated bases of the leaves . . ‘ : . 2, Isoxtzs, 
I. SELAGINELLA, Beauv. 
Prostrate or ascending, often tufted and moss-like plants with leafy 
branches. Leaves small, either uniform and imbricating, or of 2 forms, 
one large and distichous, the other small and placed on one side of the - 
stem. Spore-cases spiked. 
A very large tropical genus, rare in temperate climates. 
1. S. selaginoides, Gray (fig. 1260). Common Selaginella, or Lesser 
Clubmoss.—Stems slender, prostrate, much branched, forming moss-like 
patches 3 or 4 inches in diameter. Leaves spreading, lanceolate, pointed, 
1 to 12 lines long, not densely crowded. Fruiting branches ascending 
or erect, solitary and simple, with rather longer leaves; those of the spike 
or fruiting part fully 2 lines long, lanceolate, and bordered with a few fine 
teeth. Spike 3 to # inch long, the upper spore-cases filled with a minute 
powdery dust, the lower containing larger grains. Lycopodiwm selagi- 
noides, Linn. ! 
_ In moist mountain pastures, and wet, stony places, in Europe, Asia, and 
North America, extending from the Alps and Pyrenees to the Arctic regions. 
Not uncommon in Scotland, northern and central England, Wales, and 
Ireland. fr. summer and autumn. 
1, SELAGINELLA, 
Il. ISOETES. QUILLWORT. 
Stock very short, rooting at the base, bearing a tuft of linear leaves, the 
whole plant usually under water. Spore-cases more or less enclosed within 
the enlarged base of the leaves, those of the inner leaves filled with minute 
powdery granules, those of the outer leaves containing larger grains, at first 
cohering in fours. 
A small genus, widely spread over the greater part of the globe. 
1, X. lacustris, Linn. (fig. 1261). Huropean Quillwort—A peren- 
nial, of a bright green, forming dense tufts under the water. Leaves 
narrow-linear, thick, and nearly terete or 4-angled, much like those of 
several Monocotyledons, varying from 2 to 6 inches long, their enlarged 
bases giving the plant often a bulbous appearance. 
In mountain pools, and shallow lakes, in central and northern Europe, 
Noe 
