Lindsay Bourque wrote today’s entry:
Thank you to BlueRidgeKitties@Flickr for submitting today’s photo
(original image | Botany Photo of the Day Flickr Pool)!
As noted by the photographer on Flickr, Carolina horsenettle is in fact not a nettle, but instead belongs to the Solanaceae or nightshade family. Members of the Solanaceae are known for producing a diverse range of alkaloids, some of which can be toxic. In the case of Solanum carolinense, all parts of the plant contain solanine. Solanine is poisonous to humans and can irritate skin, causing a nettle-like rash. Given that the fruits of this plant look like small tomatoes, it is important not to mistake it!
Carolina horsenettle is considered to be a noxious weed in several states in the USA. It has the ability to spread vegetatively via underground rhizomes, as well as propagate by seed. Carolina horsenettle’s status as a weed is further bolstered by the fact that is resistant to many herbicides; in fact, use of herbicides will often give horsenettle the advantage by removing competing weeds.

An amazing plant. I have more respect now that I know about it’s toxicity.
Its close cousin the white horsenettle is also a noxious weed here in the desert Southwest. If it weren’t so prickly I would welcome it as a volunteer, since the flowers are beautiful. The white horsenettle’s flowers are a much deeper blue than the Carolina.
To see how similar the fruit of S. carolinense is to that of S. lycopersicum (tomato), see this comparison:
http://www.flickr.com/photos/shyzaboy/3843038755/
Pretty close, huh?
My mom grows eggplants and these little flowers look similar.
I didn’t know these are poisonous!
From Doug’s photo, it looks like a cross between a cherry tomato and eggplant.
Now I know why people used to think tomatoes were poisonous.
We have a couple of Solanaceae in the UK. The ‘worst’ we know as ”Deadly Nightshade”
Is the same elsewhere that many plants with purple leaves, spots, streaks etc are poisonous in some way? Certianly we have a few here that meet that criteria.
Is there a little crab spider hiding just under the yellow part of the blue flower? Are those ovaries or are they stamen parts? It’s really hard for this layman to tell.
A note of interest to gardeners: This plant is a host for the Colorado potato beetle
off todays subject
we heard here in florida usa that part
of british clolumbia has had an earthquake
would it be too much to ask you to check
in and let us know you are safe please
thank you yes its a weed here too
I believe the yellow parts are the stamens. There should be a single carpel in the center. You can see the style and stigma of one here http://www.flickr.com/photos/shyzaboy/3843107647/in/set-72157621698017321/ . The ovary at the base of that single carpel will ripen into a single tomato fruit.
Elizabeth, we’re just fine here. I think the earthquakes were in northern coastal BC — it barely made the local news, from what little I saw.