Influence of capitulum maturity on achene germination ofSenecio jacobaeaandCarduus nutans

摘要

The influence of capitulum maturity on achene germination was investigated forSenecio jacobaeaL. andCarduus nutansL. Germination of achenes from capitula in full flower was negligible for both species but as the floral tissues began to senesce the germination percentage rose to at least 50 for all populations investigated.S. jacobaeaachenes with floral parts abscised or absent were generally more viable than achenes with floral parts attached, and seedlings from such achenes exhibited higher growth rates.C. nutansdid not exhibit any consistent trends.