As you head outside to enjoy the last warm days of autumn, arrowheads (Sagittaria) may be one of the plants you find. There are 6 species of Sagittaria documented in Minnesota and it’s helpful to have photos of leaves, flowers and/or fruits to distinguish them.
Keep an eye out for this rare species:
Hooded arrowhead (Sagittaria calycina var. calycina) is a Threatened Species in Minnesota. It has been found in mucky river and lake floodplains and with low water levels, this is a great year to search for it.
Leaves range from egg shaped to arrow-shaped and may look similar to other Sagittaria species. Several species may grow together at the same site and flowers and fruits can help distinguish species. Look for these features:
- Hooded arrowhead leaf blades are usually held horizontal to the ground, not vertical like the other species.
- Flowers may still be present in the fall and are the lower flowers are unique – with a ring of yellow stamens surrounding a bulbous yellow-green center of tiny carpels.
- Fruits are quite distinctive with thick stalks that curve downward.
If you think you’ve found this species, note that iNaturalist uses this synonym: Sagittaria montevidensis ssp. calycina
For more information on how to identify this plant, see these websites:
MN DNR Rare Species Guide:
https://www.dnr.state.mn.us/rsg/profile.html?action=elementDetail&selectedElement=PMALI04040
Minnesota Wildflowers website:
https://www.minnesotawildflowers.info/flower/hooded-arrowhead
Please message mndnr-aquatic-plants if you have any questions about this species.