Myelochroa perisidians (Nyl.) Elix & Hale,

Moon, Kwang Hee, Ahn, Chorong & Kashiwadani, Hiroyuki, 2015, Revision of the lichen genus Myelochroa (Ascomycotina: Parmeliaceae) in Korea, Journal of Species Research 4 (1), pp. 23-32 : 30

Myelochroa perisidians (Nyl.) Elix & Hale,

Mycotaxon 29: 241, 1987.

Basinonym: Parmelia perisidians Nyl., Acta Soc. Sci. Fenn. 26: 6, 1900. Type collection. Ceylon, Rampodde, E. Almquist s. n. (lectotype in S! and isolectotype in H!).

Parmelia subsulphurata Asahina, J. Jpn. Bot. 26: 228, 1951. Type collection. Japan, Prov. Mino, Kamo-gun, Higashishirakawa-mura, August 1936, M. Yasue s. n. (lectotype in TNS!).

Myelochroa indica auct. non (Hale) Hale & Elix: Park YS, 1990 and Jayalal et al., 2012.

For other synonyms, see Hale (1976) and Kurokawa and Arakawa (1997).

Chemistry. Atranorin, zeorin, leucotylin and and its derivatives, and secalonic acid A.

Myelochroa perisidians resembles M. indica because they both have isidiate thalli; however, it can be distinguished from the latter by the loosely adnate thallus with wider lobes (0.5-2.0 mm wide) and the presence of secalonic acid A; the latter species has a hardly adnate thallus with smaller lobes (0.8-1.2 mm wide). Although the medulla of M. perisidians varies from pale yellow to almost white, that of M. indica is constantly white. Therefore, the final decision to distinguish between the two species should be a check for the presence or absence of secalonic acid A in the medulla.

This species was reported from Korea under M. indica by Park (1990) and Jayalal et al. (2012); however, Park (1990) reported that the specimens contain secalonic acid A and have lobes of 1-3 mm wide. Therefore, the specimens should be identified with M. perisidians rather than M. indica . We re-examined all materials treated under M. indica by Jayalal et al. and confirmed that all specimens contain atranorin, zeorin, leucotylin and secalonic acid A, characteristic chemical features for M. perisidians .

This species is widely distributed in Asia, having been recorded from India, Sri Lanka, Thailand, Japan ( Hale, 1976; Kurokawa and Arakawa, 1997) and Korea. The reports from Korea were made by several authors as Parmelia subsulphurata Asahina ( Kim, 1965; 1980; Kim, 1983; Ri, 1988), as P. perisidians Nyl. ( Lee, 1987) , as M. perisidians ( Jayalal et al., 2012) and as M. indica ( Park, 1990; Jayalal et al., 2012). The distribution in Korea is restricted to the southern part of the Korean peninsula, where it grows both on tree trunks and on rocks.

Specimens examined. Prov. Gyonggy (=Prov. Kyonggi), Seoul, June 1901, U. Faurie 4746 (KYO 00030581). Prov. Chungcheongnam, Mt. Jogae, on bark, elevation 310 m, January 31, 2004, J.S. Hur 040017 (KoLRI no. 007681, as M. indica ). Prov. Gyeongsangbuk, Cheongsong-gun, Budong-myeon, Sangui-ri, Mt. Juwang, en route from Daegeon temple to Mt. Janggun-bong via Backrung-am (hermitage), on rock with mosses, elevation about 270 m, October 13, 2013, K.H. Moon 13786 (NIBR); same locality, on rocks, K.H. Moon 13814 (NIBR). Prov. Gyongsangnam, Sancheong-gun, Mt. Ungseobong, on bark, elevation 587 m, October 16, 2007, J.S. Hur 070847 (KoLRI no. 007681, as M. indica ). Prov. Jeonllanam, Mt. Duryun, Daeheung temple, on rock, June 8, 2003, J.S. Hur 030310 (KoLRI no. 000248, as M. indica ); Gohung-gun, Sorokdo, on rock, elevation 15 m, March 23, 2003, J.S. Hur 030067 (KoLRI no. 000043, as M. indica ); Gohung-gun, Podu-myeon, Mt. Cheoundeung, around Geumtap temple, on bark of Zelkova serrata , elevation about 100 m, October 18, 2013, K.H. Moon 13863 and 13874 (NIBR); Gohung-gun, Podu-myeon, Namseong-ri, Mt. Mabok, en route from Mabok-sa temple to summit area, on bark, elevation about 200 m, October 18, 2013, K.H. Moon 10948 (NIBR).