Land Plants - invasive

Nipplewort (Lapsana communis) on May 29, 2019

Originally reported as Garlic Mustard (Alliaria petiolata)

Submitter does not have a specimen

Description of specimen

Patch of garlic mustard - some plants are bolting. Spreading along Old Main toward Red Fox Trail.

Commentary

Thank you, Jim! We always appreciate suspect reports. In this case, the sighting appears to be nipplewort (Lapsana communis). While not native, it generally is not nearly as much of a threat in sensitive areas as garlic mustard is. Nipplewort is easy to confuse with garlic mustard but note the axillary leaflets on the leaf stem (garlic mustard lacks these, and only ever has one leaf per leaf stem). Also, 2nd year garlic mustard adults currently have seed pods (upright cylindrical siliques) and nipplewort is either still bolting or has yellow ray flowers. Leaf shape is similar but adult garlic mustard leaves tend to be a bit more triangular. This would be a crucial find though if confirmed garlic mustard. Thank you so much for the report, and please keep your eyes out--you never know where pesky priority weeds will pop up!

Michelle Delepine
June 3, 2019, 2:11 a.m.