466 
L YCO PODIUM 
Lycopodium Linn. Lycopodiaceae. 94 sp. trop. and temp. 5 occur in 
Brit., chiefly in mountain districts, where they are known as club- 
mosses. The commonest is L. clavatum L. (often called stag-horn moss) ; 
the others are Z. Selago L., Z. alpinum L., Z. annotinum L., and Z. 
inundatum L. All but the last are xerophytic evergreen plants with 
hard wiry leaves. The stem branches frequently, apparently dichoto- 
mously, but in reality usually in a inonopodial manner. Upon it are borne 
the roots, which branch dichotomously, and are developed in acropetal 
succession. The leaves, narrow and unbranched, are usually placed 
spirally upon the stem, but in some sp. form four ranks, as in most 
Selaginellas. Many sp. have vegetative reproduction by aid of small 
bulbils in the leaf axils. [Prothalli see Bruchmann in Bot. Zeit . 1 899 p. 6. ] 
The sporangia are all alike in structure, containing spores of one 
kind only. They are placed upon the bases of leaves which are 
usually crowded together to form a terminal spike or strobilus. In 
Z. Selago some or all of the sporangia are often replaced by small 
bulbils (cf. Polygonum viviparum, Allium sp., Globba, &c.). 
Lyccpsis Linn. Boraginaceae (iv. 3). 3 sp. Eur., As. Z. arvensis L., 
small bugloss, in Brit. 
Lycopus Tourn. ex Linn. Labiatae (vi. n). 10 sp. N. temp. Z. eu- 
ropaeus L., gipsy wort, in Brit. 
Lygeum Linn. Gramineae (vi). 1 sp. Medit. Z. Spartum Loefl., one 
of the esparto-furnishing grasses (see Stipa and Ampelodesma). 
Lygodium Sw. Schizaeaceae. 25 sp. trop. and temp. They are of 
interest as twining ferns. The stem remains comparatively unde- 
veloped, but the leaf has unlimited apical growth, and the long 
midrib twines around supports like the stem of the hop, bearing 
pinnae at intervals. The leaves are borne on the stem in one dorsal 
row. The sporangia are in a double row on the back of the fertile 
pinnae, and each is surrounded by a cup-like indusium. 
Lyonia Nutt. Ericaceae (11. 4). 16 sp. E. As., N. Am., 1 circumpolar. 
Like Andromeda, into which some sp. are sometimes placed. 
Lyperia Benth. Scrophulariaceae (11. 7). 33 sp. S. Afr. United to 
Chaenostoma in Nat. Pfl . 
Lysimachia (Tourn.) Linn. Primulaceae (ill). 90sp. temp, and sub-trop., 
esp. N. Hemisph.; 4 sp. in Brit. Z. vulgaris L., yellow loosestrife, is 
said by Muller ( Fert . of Firs.) to occur in two forms, one in sunny 
places with large firs, suited to crossing, and one in shady spots with 
small self-fertilised firs. Z. nemorum L., yellow pimpernel is common, 
and Z. Nummzilaria L., moneywort, is frequent, though it is said 
never to set seed in Brit. 
Lysipomia H. B. et K. Campanulaceae (ill). 7 sp. Andes. 
Lytliraceae. Dicotyledons (Archichl. Myrtiflorae) . 21 gen. with 360 
sp., in all zones but the frigid. Herbs, shrubs, or trees ; leaves 
usually opp. , entire, simple, with very small stipules. Firs, in racemes, 
panicles, or dichasial cymes, $ » regular or zygomorphic, usually 4- or 
