Malmidea coralliformis
Malmidea coralliformis is a corticolous, crustose lichen in the family Malmideaceae. It was described in 2011 from northern Thailand. The species has a densely warted thallus with coral-like branching warts and ascospores that lack septa and are. It resembles M. aurigera but lacks atranorin and tends to have larger spores.
Taxonomy
The species was introduced as Malmidea coralliformis by Klaus Kalb in 2011 as part of a study establishing Malmidea and its family Malmideaceae. The holotype was collected in Thailand, Chiang Mai province, Doi Suthep–Pui National Park at about 700 m elevation, in a humid Dipterocarpus forest. The epithet coralliformis refers to the conspicuous, partly ramified, coral-like warts on the thallus.
Description
The thallus forms a thin, crust-like growth on bark and is densely warted, with individual warts about 0.2–0.3 mm high and 0.1–0.3 mm wide that often coalesce and branch; soredia and isidia are absent. The medulla is whitish and reacts K+. Apothecia are, rounded and 0.7–1.1 mm in diameter; the is brown to dark grey-brown with a thin, margin of the granifera type. The rim tissue is hyaline peripherally and internally shows a medullary layer of loosely arranged, arranged hyphae bearing hydrophobic granules that partly dissolve in potassium hydroxide solution with a greenish-yellow reaction. The is brown, the is blackish-brown and K–, and the hymenium is 75–100 μm high. Asci are 60–70 × 13–15 μm. Ascospores number 6–8 per ascus, are colourless, ellipsoid, non-septate and, measuring 10–17 × 6–10 μm. The authors report several unknown xantholepinones as the detectable chemistry and note the absence of atranorin.
Habitat and distribution
The species is known from northern Thailand, where it grows on tree bark in humid evergreen Dipterocarpus forest around 700 m elevation. The original material was collected along the trail to Monthanthan waterfall in Doi Suthep–Pui National Park.