LEIFIDIUM ¹

Gintaras Kantvilas ²

Leifidium Wedin, Pl. Syst. Evol. 187: 235 (1993).

Type: L. tenerum (Laurer) Wedin

Thallus fruticose, whitish, pale grey or tinged pale brownish or pink, richly branched and entangled, forming extensive cushions, tufts or festoons of terete, slender, main branches 0.5–1.5 mm wide and secondary branches that taper to a point. Photobiont trebouxioid, with cells globose, 9–14 µm diam. Ascomata mazaedia, black, globose, 1–2 mm diam., terminal, elevated conspicuously above the body of the thallus, covered throughout development by a thin, stiff exciple that is shed at maturity as a thin cap; spore dispersal passive. Ascospores simple, globose, hyaline to pale grey, 6–7.3–8 µm diam., smooth or with a little ornamentation from adhering mazaedial material that mainly dissolves in KOH. Conidiomata pycnidia, immersed at the apices of the branchlets; conidia ellipsoid to oblong, 3–4 × 1.5 µm. Chemistry: sphaerophorin (thallus K–, KC–, C–, P–, UV+ white).

A monotypic genus, closely related to Bunodophoron, both genera originally being subsumed within Sphaerophorus (not present in Tasmania). It differs from Bunodophoron by the entirely terete thallus and by the angiocarpic development of the terminal mazaedia which remain enclosed by the exciple until maturity.

Key references: Wedin (1993, 1995, 2001).

1 Leifidium tenerum (Laurer) Wedin

Pl. Syst. Evol. 187: 235 (1993); —Sphaerophorus tener Laurer, Linnaea 2: 45 (1827).

Widespread throughout austral latitudes, including the south-eastern Australian mainland, New Zealand, southern South America and subantarctic Macquarie Island. In Tasmania, it is very common and widespread on bark, wood, soil and rocks, especially in cool temperate rainforest where it forms conspicuous festoons on the trunks of mature trees as well as on the branches of understorey trees and shrubs. It is also common in eucalypt forest, woodland, heathland and alpine treeless vegetation. In drier areas, it becomes increasingly confined to moister microhabitats, mainly on rocks, where it forms spreading swards intertwined with bryophytes. On exposed rocks, especially at alpine elevations, the thallus frequently becomes rather robust and abraded, and forms dense cushions. It is such specimens that in earlier literature were misidentified as Sphaerophorus fragilis (L.) Pers., a Northern Hemisphere lichen. Leifidium tenerum could sometimes be mistaken for a species of Cladia or Cladonia, but species of those genera have a hollow thallus.

Mother Cummings Peak, 41°40’S 146°32’E, 850 m, 1986, A, Moscal 12334 (HO); Den Hill, 42°27’S 147°05’E, 830 m, 2004, G. Kantvilas 100/04 (HO); Crest Range, 43°17'31"S 146°30'26"E, 960 m, 2016, G. Kantvilas 176/16 (HO).

References