|What is this flower?|
I spent well over two hours last night trying to get an ID on a new flower blooming in the vacant-lot prairie. It wasn't in my wildflower books, at least not that I could recognize, and I was really thrown by it's combination of features. It had a disc like a sunflower, but what should have been simple rays were notched twice. It looked like a cross between a sunflower and a gaillardia.
I was stumped- sunflower's disc, gaillardia's rays. Blue-grey-green foliage with scattered spiney serrations along the leaf edges. What to do? Well, I sent up a distress flare to my botanically inclined contacts. What's weedy, has notched rays, a sunflower-like disc, and grows in Texas? I needed to know. After consulting with my naturalist friends, we decided it was a weird-looking Texas blue weed (Helianthus ciliaris). Generally, when you can't quite convince yourself an ID is right, that's because it isn't.
Not in this case, however. I visited the plant again the next morning (such was my desire to GET IT IDENTIFIED), and another bud had opened. No notches in the rays. Now I could rest easy, having found a second, fairly typical, specimen of blueweed. Individual idiosyncrasy is the risk you run when you only have a few specimens from which to make a judgment. I actually liked the extra decorative flourish from my unusual variant's notched petals, but they sure did throw me. When I dug a little deeper to find out more about this new plant, a descriptor that stuck out to me was "highly variable". That phrase tipped me over into certainty of my ID.
Despite its weediness, blueweed is actually native to the southwest. In Texas, blueweed is more typical of the panhandle and trans-pecos region than it is of the metroplex. Livestock don't eat it, it reproduces by rhizome, and it prefers poor soils and disturbed areas. Another term associated with this new flower: noxious weed.
Blueweed is classified as a "noxious weed" in the states of Washington and Oregon. This plant can be aggressive. It's highly drought tolerant, and, like cattails and phragmites, it grows from rhizomes. This means that mechanical chopping of the roots can multiply your problem. Like a starfish, each fragment regenerates into a new plant. Biological control isn't an option either- blueweed is highly resistant to natural pests. Sunflower beetles leave them alone.
It is intriguing to see this sunflower functioning as a small part of my urban prairie, while in other places it can be a real problem. Washington state's King County noxious weed page suggested that perhaps it is our native grasses down here that help reign in this weed. Competition from our diverse grassland may keep blueweed from becoming an aggressive pest in its home turf, but there is no such checking force in the Pacific Northwest. I suppose this plant could serve as a reminder: what seems innocuous at home isn't always universally so. We should be careful with what we plant.
In other news, I added three new species to my vacant-lot prairie plant list. These include the aforementioned Helianthus ciliaris, and also Cooperia drummondii, and Asclepias viridis.
|Another picture of ratany- to me it looks like an orchid when the flowers are open|
I've included more pictures and the updated plant list after the jump.
|Pink ladies, Oenothera speciosa|
|texas vervain, Verbina halei|
|Common Name||Latin Name||Date Observed|
|antelope horn||Asclepias asperula||17-May|
|green antelope horn||Asclepias viridis|
|evening rain lily||Cooperia drummondii||17-May|
|hill country rain lily*||Cooperia pedunculata||17-May|
|engelmann daisy||Engelmannia peristenia||17-May|
|indian blanket||Gaillardia pulchella||17-May|
|scarlet gaura||Gaura coccinea||17-May|
|prairie verbena||Glandularia bipinnatifida||17-May|
|texas blue weed||Helianthus ciliaris||22-May|
|texas bluebonnet||Lupinus texensis||17-May|
|sensitive briar||Mimosa nuttallii||17-May|
|pink ladies||Oenothera speciosa||17-May|
|texas frog fruit||Phyla nodiflora||17-May|
|prairie parsley||Polytaenia nuttallii||17-May|
|prairie coneflower||Ratibida columnifera||17-May|
|two-leaf senna||Senna roemeriana||17-May|
|carolina horse nettle||Solanum carolinense||17-May|
|diamond flowers||Stenaria nigricans var. nigricans||17-May|
|green thread||Thelesperma filifolium||17-May|
|western spiderwort*||Tradescantia occidentalis||17-May|
|texas vervian||Verbena halei||17-May|