Malmidea eeuuae is a corticolous (bark-dwelling), crustose lichen in the family Malmideaceae. It was described in 2011 from Khao Yai National Park in north-eastern Thailand. The species has a finely warted thallus and non-septate, halonate ascospores, and it differs from M. coralliformis by its larger spores.
The species was introduced as Malmidea eeuuae by Klaus Kalb in 2011 within a study on Malmidea and the family Malmideaceae. The holotype was collected in a very disturbed tropical rainforest near the students' lodges (Ban Krong Kaew) in Khao Yai National Park, Nakhon Ratchasima province, at about 760 m elevation. The specific name honours Jutarat Sutjaritturakan ("Eeuu"), a Thai lichenologist.
The thallus is thin, crust-like and continuous (about 150âÂÂ200 üm thick) on bark, densely warted () with warts 0.1âÂÂ0.15 mm high and 0.1âÂÂ0.25 mm wide; soredia and isidia are absent. The medulla is cream-coloured and reacts potassium hydroxide (KOH)-positive (dark orange to orange-red). The is (cells 5âÂÂ8 üm in diameter). Apothecia are , rounded to slightly , 0.2âÂÂ0.5 mm across and 0.1âÂÂ0.2 mm high; the is plane to slightly convex and light leather-brown to tawny, with a thin margin of the granifera type that starts entire and prominent but becomes slightly recurved and warty; the margin is 80âÂÂ130 üm thick and whitish to cream. The is hyaline at the periphery and internally shows a medullary layer of loosely arranged, periclinal hyphae with constricted septa, 30âÂÂ50 üm wide, bearing yellowish to ochraceous-yellow hydrophobic granules that partly dissolve in KOH with a yellowish to greenish-yellow reaction. The is about 50 üm high and chocolate- to olive-brown; the is 50âÂÂ75 üm high, brown and KâÂÂ; the hymenium is 100âÂÂ120 üm high and hyaline. Asci measure 55âÂÂ70 à16âÂÂ20 üm. Ascospores number 4âÂÂ6 (more rarely up to 8) per ascus, are colourless, ellipsoid, non-septate and , typically 16âÂÂ20 à8âÂÂ11 üm with a 1âÂÂ1.5 üm . Reported chemistry includes xantholepinone G (major), contortin (submajor), concontortin (minor) and three unknown xantholepinones (minor).
Known from Khao Yai National Park, Malmidea eeuuae grows on tree bark in very disturbed tropical rainforest around 760 m elevation, near the students' lodges at Ban Krong Kaew.