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The chromosome morphology of two Korean Lactuca (L. indica, L. triangulata) is reported herein. The chromosome number and karyotype of a naturalized plant, L. scariola are reported for the first time. The basic chromosome number was x = 9. Polyploid forms were not recorded. The karyotypes of L. indica, L. scariola, and L. triangulata were 2 n = 18 = 2m+ 7 sm, 2 n = 18 = 1m + 6 sm+ 2 st, 2 n = 18 = 2m + 5 sm+ 2 st, respectively. Both L. indica and L. triangulata had satellites at the ends of their short arms. The haploid genome lengths of L. indica, L.scariola, and L. triangulata were 56.3 , 35.3 , and 72.5 respectively. Each chromosome length of naturalized L. scariola was 2.7-5.2 ; the smallest among Korean Lactuca. The chromosome lengths of L. indica and L. triangulata were 4.7-7.6 and 2.9-7.9 , respectively. The karyotype of L. scariola differed from that of L.indica and L.triangulata both of which belong to sect. Tuberosae. Therefore, L. scariola is thought to belong to sect. Lactuca subsect. Lactuca.

Genus Taraxacum propagated through diploid sexual reproduction and polyploid agamospermy. The cluster analysis of Korean(2 species, 4 population), Japanese (2 species 4 taxa 6 population) and Taiwanese (1 species, 3 population) Taraxacum species using 15 measured capitulum morphological characters was conducted to study the speciation of diploid Taraxacum in East Asia. We measured 15 capitulum morphological characters including length of capitulum, length and shape of outer-involucre, corniculate appandage. Within one population, these characters were very various and were overlapped. The result of cluster analysis using morphological character showed that all species were clustered into four groups (Korean species & T. japonicum group, T. platycarpum subspecies group, T. platycarpum subsp. hodense group, T. formosanum group). Korean species, T. hallaisanense (diploid) and T. ohiwanum (diploid, triploid) were clustered into T. japonicum that was occurred in Kansai provinces of Japan. Therefore, we could infer that Korean species was closely related to Japanese T. japonicum of Japanese species.