Rhizocarpon parvum
- Innhold
- Morphology
- Chemistry
- Habitat
- Comment
- Look-alikes
Morphology
Thallus areolate, up to 1 cm diam., parasitic on Tremolecia atrata when young, later possibly becoming autonomous; hypothallus well developed, black; areolae up to 0.2 mm diam., bright yellow, slightly shiny, scattered, angular to orbicular, plane, smooth; medulla KI+ dark violet. – Apothecia up to 0.3 mm diam., black, epruinose, orbicular to angular, plane to weakly convex, with a distinct margin; excipulum brownish black in the rim, paler in the inner part, K+ red; hypothecium dark brown, K–; hymenium colourless; epihymenium brownish black, K+ red; no crystals or granules in the apothecia; ascospores 8 per ascus, 1-septate, dark green to dark brown, 9–14 × 5–7 µm. – Conidiomata not seen.
Chemistry
Not examined.
Habitat
On calciferous schist in the alpine region. In Norway known from a single locality (Finnabubjørnen, Ullensvang, 1200 m alt., 1907, the holotype).
Comment
The species is very poorly known. We have examined six of the ten specimens listed in the protologue, but only the holotype was found to belong to the species. This specimen is unfortunately very scanty and did not allow examination by TLC.
