Umbilicaria africana (Jatta) Krog & Swinscow

Nordic J. Bot. 6, 1: 79 (1986).

Basionym: Gyrophora caplocarpa var. africana Jatta, Annali Bot. 6: 408 (1909).

 

Thallus: 1 - 3 - 14 cm wide; entire or lobes usually deeply dissected, but in some specimens only shallowly dissected; margin sometimes with narrow laciniae transgrading into cilia. Upper side smooth, in the centre of old specimens irregularly-warted, sometimes verruculose-corticate; colour uniformly grey to darkgrey, sometimes with a white necrotic cover, mainly in the centre of old plants. Lower side smooth, pale yellowish grey to greybrown, lightest in the centre, towards the margin with irregularly distributed black spots of variable size, which may cover nearly the whole surface, or be almost absent. Rhizinomorphs present, mainly on the margins (cilia), but often also, and occasionally exclusively, scattered on the lower side towards the margin, grey or sometimes, when on black part of lower side, with black spots at base, big and often branched, 1 - 2 mm long, at base sometimes flattened. Thalloconidia on all black spots of the lower surface, 15 - 22 - 25 µm diameter and composed of ca. 4 - 8 - 10 cells. Apothecia uncommon, leiodisc or omphalodisc, raised. Spores simple, hyaline, 11 - 12 - 16 x 4 - 5 -8 µm (Krog & Swinscow 1986: 79; Sipman & Topham 1992: 65).

Photobiont: Data lacking.

Chemistry: Gyrophoric acid in small amounts (Krog & Swinscow 1986: 80; Sipman & Topham 1992: 65).

Ecology: Saxicolous on silicious rock. In East Africa from 3000 to over 5000 meter, mainly above 4000 m.

Distribution Type: Ethiopia, Kenya, Tanzania, Uganda, Zaire, Antarctica, Columbia, Ecuador, Java.

Note: [Mainland] African representatives of Umbilicaria africana (Krog & Swinscow 1986) differ by a considerably larger size of thallus and rhizinomorphs (Sipman & Topham 1992: 65). They usually possess apothecia, whereas fruiting bodies are uncommon in the Canary Islands.

Distributions