Lycopodium L.
Sporangia 1-3 mm. diam., reniform to subspherical, yellowish, solitary in axils of sporophylls, aggregated into stalked or sessile strobili, or scattered along stems, dehiscing by slit transverse to sporophyll. Spores tetrahedral, with 3 radiate ridges on flat surface. Stems dichotomously branched, with numerous scale-like lvs. Lvs imbricate, alike, or more or less distichous and dimorphic. Subcosmopolitan, with over 150 spp.
Key
The treatment of the spp. belonging to the sections Selago and Phlegmaria is conventional. There occurs an almost complete intergrading series of forms linking "typical" australianum, varium and billardieri. Certain forms have been placed either under australianum or varium. Forms with more or less ill-defined strobili are usually placed under Kirk's var. gracile of billardieri, of which Colenso's novae-zelandicum may be regarded as the extreme form. How far the intergrades are due to habitat modifications and how far to genetical differences is not clear, though it is certain that the habitat has great influence. For a lengthy discussion see Holloway in T.N.Z.I., vols. 48-51, 1916-1919. In 51, 161-216 the numerous forms are discussed and illustrated.
