Phlegmariurus, Holub, Preslia

Øllgaard, Benjamin, Boudrie, Michel & Cremers, Georges, 2020, The Lycopodiaceae of Guyana, Suriname, and French Guiana, Phytotaxa 433 (2), pp. 101-134 : 111

4. PHLEGMARIURUS Holub, Preslia 36: 21. 1964.— Type: Phlegmariurus phlegmaria (L.) T.Sen & U.Sen (= Lycopodium phlegmaria L., Sp. Pl. 2: 1101. 1753).

Plants epiphytic or terrestrial, pendulous, recurved, erect, or ascending, isotomously branched throughout (Guianan species). Roots arising from the stem stele, descending through the cortex to the stem base, here emerging as one basal tuft. Shoots homophyllous or gradually to abruptly heterophyllous, the constriction of distal divisions of heterophyllous species associated or not with presence of sporangia. Sporophylls and vegetative leaves alike or sporophylls shorter, not peltate, persisting and green after sporangium dehiscence. Sporangia axillary, reniform, isovalvate, with a short slender stalk; sidewalls of sporangium epidermal cells sinuate, thickened and lignified together with the inner walls. Spores foveolate or fossulate. Gametophytes usually subterranean or deep in epiphytic substrate, mycorrhizal, cylindrical with radial or bilateral symmetry, with pluricellular, uniseriate hairs among the gametangia.

Perhaps 250 species worldwide, 14 in the Guianas, none of them are endemic. Phlegmariurus is pantropical with few temperate species. Species diversity is highest throughout the tropics in evergreen montane forests, and in the wet Andean grass and shrublands in South America.

The genus Phlegmariurus until fairly recently was generally included in the genus Huperzia . However, Phlegmariurus is distinct from Huperzia with regard to spore type and the absence of gemmae. The species of Huperzia are entirely terrestrial whereas the majority of Phlegmariurus species are primarily epiphytic, the terrestrial species being derived from epiphytic species. No intergeneric hybrids are known ( Øllgaard 2012 b, Øllgaard & Windisch 2019).