Observations on germination and seedling establishment of Senecio erucifolius L. in relation to its northern boundary

The perennial species Senecio erucifolius L. is rare in the northern parts of The Netherlands. Its very local occurrence can hardly be explained by special environmental conditions. Ripe achenes are not formed until the middle of September. The achenes show no dormancy, but the initial temperature requirements for germination are relatively high. According to germination experiments, germination may take place during the whole winter half of the year, but the seedlings are very susceptible to frost, which reduces establishment from seeds. The apparent absence of seedlings in the field confirms these conclusions.