Wednesday, May 5, 2010

Canadian Toadflax (Nuttallanthus canadensis)

The Canadian Toadflax (Nuttallanthus canadensis) is one of three Nuttallanthus species that grow in this area. The other species are the Apalachicola toadflax (Nuttallanthus floridanus) and the Texas Toadflax (Nuttallanthus texanus).

Nuttallanthus canadensis is known by several common names; Canada Toadflax, Canadian Toadflax, Oldfield Toadflax, Old-field Toadflax, or Blue Toadflax. It is the first toadflax to bloom each year. N. floridanus and N. texanus bloom later.

When I first encountered these species, it took me some time and observation to be able to differentiate between them. I thought the variation was due to variations in growth patterns resulting from different qualities of soil. However, the flowers of these species clearly differ in size, color, and color pattern and can be identified on the basis of these characteristics.

They grow in patches along roads – where these photos were taken – and in fields.

An individual flowering stem

An individual flowering stem from above

Each flower is about 1/4-inch in long. Both the purple and white colors are solid; they show no sign of color veins.

Canadian Toadflax (Nuttallanthus canadensis) grows in the eastern Canadian provinces and United States has been introduced to and become established in Washington state, Oregon and California.

Click on an image to view a larger image

Distribution Map:

- United States Department of Agriculture Plants Database: Nuttallanthus canadensis (Canadian Toadflax)

Identification resources:
- Southeastern Flora: Oldfield toadflax (Nuttallanthus canadensis)

Related posts:

- 2010: Year Of The Wildflower


Rosie@leavesnbloom said...

our native toadflax in Scotland has just the same flower only ours creeps along the ground and climbs up old walls.

JSK said...

I'm so glad you have one. It's one of my favorites.
I did an image search and found a photograph of 'your' toadflax. It's a lovely little flower. Turns out it grows in the United States but north of Georgia.