New or otherwise interesting Lichens. VI, including a lichenicolous fungus Kalb, Klaus Buaruang, Kawinnat Mongkolsuk, Pachara Boonpragob, Kansri Phytotaxa 2012 2012-01-25 42 35 47 3XQ9F Kalb & Mongkolsuk Kalb & Mongkolsuk 2012 [151,632,461,487] Lecanoromycetes Malmideaceae Malmidea Fungi Lecanorales 9 44 Ascomycota species tratiana sp. nov.   Sicut Malmidea furfurosa (Tuck. ex Nyl.) Kalb & Lückingsed thallo leve et sporis minoribus differt.   Type:—  THAILAND. Trat Province: Muang District, near Ban Nam Chieo, in a ± disturbed mangrove forest on  Rhizophora apiculata, ±  3 m, 12°10’25’’ N, 102°28’37’’ E,  25 February 2011, K. Kalb & P. Mongkolsuk ( holotype RAMK, isotype hb. Kalb 38852).   Etymology:—This species is named after the typelocality in Trat Province.  Thallus crustose, corticolous, continuous, 150–250 µmthick, ± smooth or slightly bullate, green to greengrey, phenocortex ca. 10–15 µmthick with small crystals, algal layer 80–100 µmthick, medulla indistinct, ca. 60–150 µmthick, prothallus whitish, soralia and isidia absent. Photobiont chlorococcoid, cells 7–10 µmdiam. Apothecia sessile, round, 0.3–0.5 mmdiam. and 0.25–0.35 µmhigh; disc plane to slightly concave, pale leather brown to grey-brown; margin of piperis- type( Kalb et al.2011), thick, prominent, black. Thalline exciple absent, proper exciple dark brown internally, outer part ± hyaline, 45–100 µm wide without hydrophobic granules, KOH-. Hypothecium 70–100 µmhigh, blackish brown, KOH-. Epihymenium hyaline. Hymenium 70–80 µmhigh, hyaline. Asci 60–70 × 15–18 µm, 6–8 spored. Ascospores non-septate, wall uniformly thickened, halonate, ellipsoid to fusiform, 9–11 × 5–6 µm, halo 1 µmthick. Pycnidia not observed. Chemistry: an unknown spot with R fvalues 37, 9, 23 insolvents A, B’, C (Elix & Ernst-Russell 1993).   Notes:—  Malmideaspecieswith a piperis- typeexciple are rare in the tropics but more abundant in subtropical regions or at higher elevations. On the other hand, species with a granifera- typeexciple are more common in the tropics or at lower elevation. Kalb et al.(2011)mention only one species (  Malmidea perplexaKalb) with a piperis- typeexciple for Thailand.  Malmidea tratianais readily distinguished from that species by its dark brown hypothecium (hyaline in  M. perplexa) and the black margin of the apothecia (whitish grey to dark brownish grey in  M. perplexa).  Malmidea tratianadiffers from the neotropical  M. furfurosa(Tuck. ex Nyl.) Kalb & Lückingby the ± smooth thallus (granular to isidiose in  M. furfurosa) and smaller ascospores (9–11 × 5–6 µmversus 11–14 × 5–7.5 µm). Furthermore, no secondary lichen products could be detected in  M. furfurosaby means of TLC. 3128939316 2011-02-25 K, P, RAMK Thailand 3 12.173612 Ban Nam Chieo 21 102.476944 Muang District 9 44 1 Trat holotype