Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Germination ecology of barbwire Russian thistle.

Abstract

Salsola paulsenii is a coarse, spiny annual weed introduced to semi-arid and arid portions of the intermountain and SW USA. It is similar in ecological requirements to Salsola kali var. tenuifolia. S. paulsenii seeds disperse without the necessity of the plants tumbling as is the case with most ecotypes of S. kali. The seed has temp.-related after-ripening requirements, but these are less stringent and break down sooner after maturity than S. kali seed. The shorter after-ripening requirements permit germination during the winter, which is a distinct competitive advantage under arid conditions with winter precipitation and summer drought.