Sagema potentillae Poelt & Grube

Data Set Maintenance: Data set compiled and standard item. Data set author(s): Kainz C. (03-04-02). Data set not revised; to be published after submission.

Nomenclature: Current taxonomic status: accepted or basionymous. Taxonomic rank: species. Sagema. Lecanoraceae Körb. (1855); Lecanorineae; Lecanorales.

Taxonomic Literature: Grube M., Poelt J., Graphis Scripta 5(1): 69-72 (1993).

Biogeography: Alpine. Continent: Asia-Temperate.

Ecology: Biotroph; lichenized; lignicolous (dead twigs of Potentilla arbuscula S. Don); episubstratic.

Thallus: Crustose; separate thallus parts thin. Upper Surface: White or pale grey (sordid); special structures absent.

Reproduction Strategy: With sexual (and possible asexual) stages. Ascocarps: Apothecioid, orbicular, forming independently from the host thallus or mycelium, soon sessile, strongly constricted at the base, .3-.6 mm in diam.. Margin: Slightly crenulate (or not crenulate), excluded, distinct (not or only when young slightly protruding). Disk: Plane (but occasionally with minute humps caused by protruding ascus tips; when moistened the asci are recognized as clear points under the stereo microscope) or weakly convex. Amphithecial Cortex: 60-100 µm wide at the base. Epithecium: Apical cells pale brown (in N slightly brighter brown, without reddish tones), soluble in 10% KOH (insoluble in N). Hymenium: 120-140 µm high. Hypothecium: Up to 10 µm high.

Asci: 80-100 µm long, 30-35 µm wide; dehiscence lecanoralean (clavate to saccate, 'chambre oculaire' often indistinct).

Ascospores: c. 8 per ascus, spores 8 per ascus, broadly ellipsoid (when free) or oval, 30-40 µm long, 15-21 µm wide; septa absent; wall thick (2-4 µm, an outer wall layer, c. 2 µm thick, can be distinguished quite clearly, delimited by a thin lammella on the outside, and a more refractive layer on the inside), distinctly differentiated into primary and secondary wall (2-4 µm, an outer wall layer, c. 2 µm thick, can be distinguished quite clearly, delimited by a thin lammella on the outside, and a more refractive layer on the inside), not ornamented (2-4 µm, an outer wall layer, c. 2 µm thick, can be distinguished quite clearly, delimited by a thin lammella on the outside, and a more refractive layer on the inside).

Secondary Metabolites: Present, isousnic acid (plus a not identified triterpenoid), of the following substance class(es): (tri-)terpenoids.

Spot Tests: Upper surface: K – (negative), C –, KC – (or pale yellowish), PD –.

(report generated 04.Okt.2007)