This study aims to identify the most tolerant species under salinity stress from amongst Asteraceae and Poaceae. The seeds of six species were exposed to different concentrations of CaCl2 (0, 9, 18, 45, 90 mM) and NaCl (0, 17, 34, 85, 170 mM), and germination was measured once every two days. The results indicated that percent germination of the six species of Asteraceae and Poaceae seeds were affected differently by changes in salinity concentration. Seed germination was reduced as salinity levels increase, and longer mean germination times correlated to lower percent germination and earlier germination cessation. Both Asteraceae and Poaceae seeds had the highest germination rates at 18 mM CaCl2 and 34 mM NaCl, and seed germination and growth were severely reduced at salinities greater than 90 mM CaCl2 and 170 mM NaCl. In the seeds of Poaceae, salt resistance was strong in the order of Miscanthus sinensis Andersson, Pennisetum alopecuroides (L.) Spreng., and Phragmites communis Trin. In the seeds of Asteraceae, salt resistance was strong in the order of Dendranthema zawadskii var. latilobum (Maxim.) Kitam, Aster yomena (Kitam.) Honda, and Dendranthema boreale (Makino) Ling ex Kitam.. Overall, the germination rate was higher in Asteraceae than in Poaceae. This study demonstrated that Dendranthema zawadskii var. latilobum (Maxim.) Kitam. is the most tolerant species and that a relationship exists between the salt tolerance of percent germination and the mean germination time in the leaves.

An unrecorded alien species plant, Phalaris paradoxa L. (Poaceae) was found in Andeok-myeon, Seogwipo-si, Jeju island, Korea. It is native to the Mediterranean region of Europe, and it is currently found worldwide. Phalaris paradoxa is distinguishable from related taxa (P. arundinacea, P. canariensis, P. minor and P. arundinacea var. picta) in Korea by the following combination of characterstics: spikelets in clusters (the upper central fertile spikelet surrounded by six lower sterile spikelets), wing of the keel. This taxon was named ‘Nal-gae-ca-na-ri-sae-pul’ in Korean based on its character. We provide its description, illustrations, photographs and a key of related taxa in Korea.