Help document one of Minnesota's rarest Arrowheads

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:

  1. Hooded arrowhead leaf blades are usually held horizontal to the ground, not vertical like the other species.
  2. 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.
  3. 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.

Publicado el miércoles, 29 de septiembre de 2021 a las 11:50 AM por mndnr-aquatic-plants mndnr-aquatic-plants

Comentarios

I was studying Sagittaria species in preparation for next summer. I found in iNaturalist that that there are 18 observations on S. gramineum. According to a number of references, we don't have this species in this State. Is that true? Could they be Alisma species instead.

Anotado por bogwalker hace cerca de 2 años

Thanks for the question and your review of these observations. I will try to review them also in the next few weeks. In general, if Sagittaria is not in flower or fruit, I think it's appropriate to leave it at the genus level id. Instead, I think many observers assume that narrow-leaved plants are S. gramineum. I'll need to look at individual photos to see if I think I can determine Alisma from Sagittaria.

Donna Perleberg

Anotado por mndnr-aquatic-plants hace cerca de 2 años

Añade un comentario

Entra o Regístrate para añadir comentarios