Myelochroa entotheiochroa (Hue) Elix & Hale,

Mycotaxon 29: 240, 1987.

Basinonym: Parmelia entotheiochroa Hue, Nouv. Archiv. du Museum, ser. 4., 1: 161, 1899. Type collection: Hakodate, Japan, Faurie 104 pp. (lectotype PC, isotype in TNS!)

Parmelina entotheiochroa (Hue) Hale, Smiths. Contr. Bot. 33: 28, 1976.

Myelochroa rhytidodes (Hale) Elix & Hale, Mycotaxon 29: 241, 1987. Type collection. Amagi Pass, Prov. Izu, Honshu, Japan, S. Kurokawa 58601 (holotype US; isotype TNS!, as Parmelina rhytidodes Hale).

For other synonyms, see Kurokawa and Arakawa (1997).

Chemistry. Race 1, atranorin, zeorin, leucotylic acid and its derivatives, and secalonic acid A. Race 2, atranorin, zeorin, leucotylin and its derivatives, and secalonic acid A.

This species is characterized by the lack of soredia, reticulate wrinkles often burst open along the ridges, and the very fragile upper cortex that is often flaked away to expose the medulla.

It is easily distinguished from allied species by the wrinkled and fragile thallus, which often exposes yellow or white patches of medulla. Ridges of wrinkles found on the thallus often burst open but never produce soredia or pustules.

Hale (1976) reported leucotylin as the major chemical substance of Myelochroa enthotheiohroa; however, in Korea, 13 of 20 specimens produced leucotylin while 7 produced leucotylic acid. A similar result was also reported from Japan (Kurokawa and Arakawa, 1997).

Myelochroa entotheiochroa is one of the commonest foliose species in lowland Korea. In Korea, M. entotheiochroa has been reported as Parmelia entotheiochroa (Asahina, 1951; 1952; Kim, 1965; 1979; 1980; 1981; Park, 1976; Cho and Lee, 1980; Lee, 1987; Ri, 1988; Huneck et al., 1989), as Parmelina entotheiochroa (Hale, 1976), as M. entotheiochroa (Park, 1990; Moon, 1997; Kashiwadani et al., 2002; Hur et al., 2004; Jayalal et al., 2012) and as M. rhytidodes (Park, 1990). One specimen reported as M. xantholepis by Jayalal et al. (2012) is identified as M. entotheiochroa.

Outside of Korea, M. entotheiochroa has been reported from Japan, Nepal and Thailand (Kurokawa and Arakawa, 1997). Recently it was reported from India and Sri Lanka (Jayalal et al., 2012). It is apparently very common throughout the lowlands of the Korean peninsula.

Representative specimens examined. Prov. Gangwon (=Prov. Kangwon), Hoiyang-gun, Paekam, August 1, 1934, F. Fujikawa; Sokcho city, Mt. Sorak, E slope of Mt. Daechongbong, on bark of Abies mariesii, elevation about 1480-1708 m, July 17, 1996, Y. Ohmura 2325 & K.H. Moon (TNS); Pyeongchang-gun, Jinbu-myeon, Mapyeong-ri, Mt. Odae, beside Ohdae stream, on rocks, elevation 386 m, June 18, 2009, K.H. Moon 11009 (NIBR); Prov. Chungcheongbuk, Danyang-gun, Mt. Sobaek, on bark, elevation 647 m, October 2, 2003, J.S. Hur 030725 (KoLRI no. 000522, as M. cf. xantholepis); Prov. Gyongsangbuk, Cheongdo-gun, Unmun-myeon, Sinwon-ri, Mt. Gaji National Park, en route from Unmun Temple to Sari Temple, on rocks, elevation 220-400 m, March 26, 2009, K.H. Moon 10790 (NIBR); Prov. Gyongsangnam, Sancheong-gun, Sicheon-myeon, Jungsan-ri, Mt. Jiri, en route from Rotary hut to Mt. Cheonwang, elevation 1600 m, on bark, August 11, 2006, K.H. Moon 9004 (NIBR); Prov. Jeollanam, Goheung-gun, Geumsan-myeon, Sinchon-ri, Island Geogeum-do, seaside, elevation 9 m, on rock with mosses, October 19, 2013, K.H. Moon 13949 (NIBR); Prov. Jeju (=Prov. Cheju), Cheju-shi, Odung-dong, Kwanum temple, on bark of Prunus sp., elevation about 580 m, May 29, 2001, K.H. Moon 5927 (TNS); Cheju-shi, Jocheon-eup, Seonheul-ri, around pond Seonheul, on rocks (lava), elevation 180 m, May 24, 2012, K.H. Moon 13027 (NIBR).