In several species, grouped round the widely distributed type _Lycopodium Selago_ Linn., the comparatively short, erect or suberect, shoots form fairly compact tufts; the ordinary foliage-leaves function as sporophylls, and the sporangia are not localised on special portions of shoots. From this type, we pass to others in which the fertile leaves tend to be confined to the tips of branches, but hardly differ in form from the sterile. A further degree of specialisation is exhibited by species with well-defined cones composed of leaves (or bracts), the primary function of which is to bear sporangia and to afford a protective covering to the strobilus[93]. _Lycopodium rufescens_ Hook. An Andian species with stout dichotomously branched erect stems bears on the younger shoots crowded leaves with their thick and broadly triangular laminae pointing upwards, but on the older and thick shoots the laminae are strongly reflexed (fig. 121, A). The lower part of the specimen represented in fig. 121, A, shows tangentially elongated scars and persistent leaf-bases or cushions left on the stem after the removal of the free portions of the leathery leaves, a surface-feature which also characterises the Palaeozoic genus _Lepidodendron_. The reflexed leaves and persistent leaf-cushions are clearly seen in the piece of old stem of _Lycopodium dichotomum_ Jacq., a tropical American species reproduced in fig. 121, B. Such species as _L. erythraeum_ Spring, and others with stiff lanceolate leaves exhibit a striking resemblance to the more slender shoots of some recent conifers, more especially _Araucaria excelsa_, _A. Balansae_, _Cryptomeria_, _Dacrydium_ and other genera. [Illustration: FIG. 121. _Lycopodium._ A. _Lycopodium rufescens._ B. _L. dichotomum._ C. _L. tetragonum._ D. _L. nummularifolium._ E. _L. Dalhousianum._ F. _L. casuarinoides._ G. _L. volubile._ (From specimens in the Cambridge Herbarium and Botanic Garden. M.S.)] [Illustration: FIG. 122. _Lycopodium squarrosum._ The branches of the larger shoot terminate in cones. (From a plant in the Cambridge Botanic Garden. Reduced.)] In _Lycopodium tetragonum_ Hook., (fig. 121, C), a species from the Alpine region of the Andes, the long, pendulous and repeatedly forked branches bear four rows of fleshy ovate leaves and simulate the vegetative characters of certain conifers. [Sidenote: LYCOPODIUM] [Illustration: FIG. 123. _Lycopodium cernuum._ (From a specimen in the Cambridge Herbarium. ½ nat. size.)] _L. squarrosum_ Forst. (fig. 122) a tropical species from India, Polynesia, and other regions, is characterised by its stout stems reaching a diameter of 2·5 cm., bearing long pendulous branches with large terminal cones composed of sporophylls differing but slightly from the foliage leaves. The plant represented in the photograph serves as a good illustration of the practical identity in habit between Palaeozoic and recent genera. [Illustration: FIG. 124. _Lycopodium obscurum._]