Inula britannica var. chinensis (syn. Inula japonica ), called Geum-Bul-Cho in Korean, is a perennial herb with yellow flowers, nativeto East Asia including Korea. It has been cultivated or gathered formedicinal purposes in China and Korea. Recently planting of wildflowersalong r oadsand in gar dens hasbecom e popular in Korea andnew businesses have developed to provide seedlings. Dense plant-ing of this plant in nurseries and also in gardens has resulted inpowdery mildew infections since 1990 in Suwon and other areas ofKorea (Shin, unpublished). Though the morphological characteri-stics of the fungus were concordant to those of the genus Golovi-nomyces, its accurate identification could not be made due toabsence of the teleomorphic state. In September 2009, formation ofthe chasmothecia on the infected leaves was found in the garden ofNational Institute of Horticultural and Herbal Science, Suwon, forthe first time in Korea. White superficial colonies developed amphigenously on leavesand stems (Fig. 1A & B). Chasmothecia were formed abundantly,especially on the lower leaf surface. Conidiophores were 110-180×10-12.5 µm, straight at the base, producing conidia in chainswith sinuate edge-line. Conidia were ellipsoid to barrel-shaped, 32-38×16-20 µm, without conspicuous fibrosin bodies. Chasmotheciawere 90-120 µm in diam., blackish brown, depressed globose.Appendages were about 10-25 in number, mycelioid, curved totortuous, olivaceous brown throughout or paler upwards, 0-5-septate. Asci were 6-14 per chasmothecium, 55-75×30-42 µm, 2-spored. Ascospores were ellipsoidal to oval, 18-28×12.5-17.5 µm(Fig. 1C). Based on these morphological characteristics, this funguswas identified as Golovinomyces cichoracearum (DC.) V.P. Heluta(Braun, 1987). To confirm the identification, the ITS region ofrDNA was amplified and sequenced, and the resulting sequence wasdeposited in GenBank (Accession No. GU143089). Molecularphylogenetic reconstructions were performed using MEGA4,version 4.0 for neighbor-joining (using Tajima-Nei distances).Comparison with the sequences available in the GenBank databaserevealed that the ITS sequence shares 94% similarity with those ofG. cichoracearum parasitic on the hosts belonging to the Helian-theae. Inth e phylogenetic tree (Fig.2 ) the Korean isolate was nes, tedwithin G. cichoracearum clade (cf. Matsuda and Takamatsu, 2003) .The powdery mildew disease of Inula britannica associated withG. cichoracearum has been recorded from most parts of Europe(Farr and Rossman, 2009). In Japan, the powdery mildew on I.britannica var. chinensis was identified as G. cichoracearum, basedon its anamorphic state in 1951 (cf. Nomura, 1997), and no furtherrecords of the disease have been published. To our knowledge, this isthe first report of G. cichoracearum infections of I. britannica var.chinensis in Korea. This disease seems not to be a serious threat tothe health of established plants. Severe outbreaks of powderymildew as found in Hongcheon in 2008 and Suwon in 2009 cangreatly detract from the beauty of this native plant in landscapeplantings.