Flavocetraria nivalis (L.) Kärnefelt & A. Thell

Data Set Maintenance: Data set standard item. Data set author(s): Thell A. Data set reviewer(s): Thell A.; revised; to be published after submission.

Nomenclature: Current taxonomic status: accepted. Taxonomic rank: species. Currently accepted name Flavocetraria nivalis (L.) Kärnefelt & A. Thell. Flavocetraria. Synonyms: Cetraria nivalis (L.) Ach.
Allocetraria nivalis (L.) Randlane &

Saag; Parmeliaceae Zenker (1827); Lecanorales.

Type Information: Basionym: Lichen nivalis L. Type: Flavocetraria nivalis (L.) Kärnefelt & A. Thell.

Taxonomic Literature: Kärnefelt, I., Thell, A., Randlane, T. & Saag, A. 1994: The

genus Flavocetraria Kärnefelt & Thell (Parmeliaceae,

Ascomycotina) and its affinities. Acta Bot. Fennica 150: 79-

86.
Randlane, T. & Saag, A. 1992: New combinations of some

cetrarioid lichens (Parmeliaceae). Mycotaxon 44: 491-493.

Biogeography: Holarctic; alpine. Continent: Asia-Temperate, Europe, Northern America, and Pacific. Checklist records: Austria, Estonia, Germany, Germany, Bavaria, Great Britain, Iberic Peninsula, Italy, Sweden and Norway, and United States and Canada (continental).

Ecology: Biotroph; lichenized; terricolous.

Thallus: Foliose (erect foliose), subdivided into main parts, and secondary parts, isotomic-dichotomous, continuous throughout, lobed (erect foliose); lobes elongate, ascending; plane; erect; branches terete; unifacial; not segmented. Secondary Thallus: Trunk with intact wall, yellow, concolorous the branches. Thallus Size and Differentiation: 5-8 cm long; main branches basally not constricted; apex not curved; rounded. Thallus Outline: Irregular. Upper Surface: Yellow, subconcave, glossy (shiny), smooth; not fissurate; not foveate; not convoluted; immaculate; without patches; epruinose; not pseudocyphellate; wrinkled; eciliate; without hairs; not isidate; without isidiomorphs; not papillate, not pustulate; not sorediate (soredia extremely rare); not tuberculate; not lobulate. Lower Surface: Present, yellow, yellow in the centre; attached by holdfasts; pseudocyphellate (white plane spots); not cyphellate; wrinkled, wrinkles central or peripheral, reticulate, not predominantely oriented; not rhizinate; not tuberculate.

Hydrochasic Thallus Movement: Not performing hygrochasic thallus movement.

Upper Cortex: 30-60 % of thallus width; double-layered; epicortex non-porous (i.e., forming a syncortex). Photobiont Layer: Photobiont cells scattered, hyphal cells large, similar in size to medullar hyphae. Medulla: Single-layered, loose; hyphae without particular orientation, not widened at the septum.

Reproduction Strategy: With sexual (and possible asexual) stages. Ascocarps: Apothecioid, forming all across the thallus surface, along the margin of the thallus parts, independently from the host thallus or mycelium, sparse, 3-8 mm in diam.. Margin: Smooth, epruinose; not sorediate; not isidiate; without pseudocyphellae pseudocyphellae; not ciliate; not hirsute. Disk: Brown. Epithecium: Apical cells slightly swollen. Hymenium: 50 µm high. Interascal Hyphae: Scarcely branched, not or scarcely anastomosed.

Asci: Narrowly clavate; with distinct flanks; ocular chamber present; narrow; dehiscent by rostrum-type dehiscence.

Ascospores: c. 8 per ascus, spores 8 per ascus, ellipsoid, 5-7 µm long, 3-4 µm wide; wall thin, not ornamented.

Conidiomata: Present; stipitate; formed on projections, along the thallus periphery; supporting structure: absent.

Pycnidia: Wall black; single-layered. Conidiogeneous Cells: Intercalar. Conidia: Bifusiform; 5-6 µm long; 1.2-1.5 µm wide.

Secondary Metabolites: Present; only in the upper part of the cortex or throughout the cortex, usnic acid, of the following substance class(es): dibenzofurans [and usnic acids], metabolite(s) of unresolved identity: absent.

(report generated 04.Okt.2007)