Calicium chlorosporum
Description : Thallus verrucose to almost immersed, pale yellowish green. Apothecia 0.6–1.3 mm tall. Capitulum broadly obconical to lenticular, with a reddish brown pruina on the lower side. Mazedium with a faint yellow pruina, especially in young fruits. Stalk shining, black or with a reddish brown pruina in the uppermost part, sometimes flattened. Exciple of densely interwoven and heavily sclerotic, dark-brown hyphae. Hypothecium dark-brown, of reticulately interwoven hyphae with flat upper surface. Asci cylindrical 31–38 × 3.5–4.3 μm, with uniseriate or slightly overlapping ascospores. Ascospores ellipsoidal, 9–14 × 5.5–7 μm, with a distinct ornamentation of spirally arranged ridges and a few irregular cracks.
Chemistry : Thallus K+ yellow to dull yellow→red, C−, Pd+ yellow to orange-red; containing norstictic acid and two unidentified xanthones.
S: Nelson (Pelorus Bridge Scenic Reserve). Known also from Australia, North, Central and South America, Africa and Japan (Tibell 1987, 1996b, 1998a, 2001b; Kalb 1991, 2001c; McCarthy 2003c, 2006; Tibell & Thor 2003; Tibell & Ryan 2004a).
Palaeotropical
Illustration : Tibell (1987: 28, fig. 8).
Calicium chlorosporum is recognised by: the slightly yellowish, C− thallus, the brown-pruinose apothecia, the faint yellow pruina on the mazedium and the distinctive spiral ornamentation of the spores. It is distinguished from C. salicinum in having a yellowish thallus containing unidentified xanthones, in the larger spores, and a faint yellow pruina on the mazedium.
