Detection of swainsonine and isolation of the endophyte Undifilum from the major locoweeds in Inner Mongolia

► Swainsonine was detected in Astragalus variabilis and Oxytropis glabra. ► Undifilum oxytropis was detected by PCR in all samples that contained swainsonine. ► Quinolizidine alkaloids were not detected in Oxytopis glabra and O. ochrocephala. ► The quinolizidine alkaloids were detected in Sophora alopecuroides.