One of my favorite spring flowers is prairie ragwort (Senecio plattensis, aka Packera plattensis). Its bright yellow flowers add welcome color to prairies every May, especially when it appears in high numbers. We always try to harvest as much seed from the species as we can when we’re doing prairie restoration projects – partly because it fills some important ecological roles, and partly because I just like it.
Prairie ragwort was blooming along our hiking trails last week. The Nature Conservancy’s Platte River Prairies, Nebraska.
Ragwort is typically a biennial, so it germinates and forms a rosette (a few basal leaves) its first season, then blooms and dies the next year. I’ve read that the rosettes can survive more than one year before blooming, but I’ve never watched closely enough to confirm that at our sites. Regardless, it’s one of a suite of opportunistic plants that can take advantage of open space created by drought, fire, and/or grazing. I have a soft spot in my heart for those species because their presence and abundance helps me read what’s happening in our prairies. When I see lots of ragwort and other opportunistic species in our sites, it tells me that the vigor of dominant grasses has been suppressed (because of weather, management, or both). Suppressing dominant grasses is a major focus of our management work because that suppression facilitates the establishment and spread of many other plant species, not all of which are “weedy”. While a number of opportunistic species (ragweeds, annual grasses, and many others) can indicate grass suppression, ragwort is nice because it also happens to be attractive – and because it flowers at a time of year when few other showy plants are blooming.
This eastern-tailed blue butterfly was feeding on ragwort at the Helzer family prairie a couple weeks ago. Near Stockham, Nebraska.
A sweat bee on ragwort at the Helzer family prairie.
Prairie ragwort attracts a large number of pollinators, including bees, flies, moths, and butterflies. It is an equal opportunity resource for pollinators because it doesn’t hide or restrict access to its pollen or nectar with funny shaped flowers that require long tongues or other specialized body parts. Everything is right there – available to any insect that lands on it. In years like this one, when ragwort appears in big numbers, it might be the most important species available to pollinators during its blooming period.
I enjoy watching the ebb and flow of ragwort populations in response to our management, but I also like to monitor its establishment and spread in our restored (reconstructed) prairies. Although its seedhead is fluffy like a dandelion, and the individual seeds can travel long distances, most end up falling near the parent plant. As a result, new populations tend to radiate outward from the initial colonizing individual, and the size of ragwort patches can be an indication of the age of a restored prairie. However, that pattern falls apart when a prairie isn’t managed with frequent disturbances because the populations can quickly shrink during years when thatch and vigorous grasses prevent seed germination and establishment.
A common checkered skipper butterfly feeds on ragwort in one of our restored Platte River Prairies last week. The short heights of the grasses surrounding the ragwort plants in this photo are a result of both drought and grazing last year.
Ragwort is certainly not a rare plant in Nebraska, or one that is of conservation concern. The droughty nature of our state helps keep populations strong, as does the prevalance of grazing in many prairies. However, I think it’s important not to judge the value of plants by whether or not they are rare. Ragwort, along with hoary vervain (Verbena stricta), common and show milkweeds (Aclepias syriaca and A. speciosa), and many other “weedy” wildflower species serve as great indicators of ecological events, step up to fill holes in weakened plant communities, and are among the more important wildflowers for pollinators in our prairies.
What’s not to like?
The Prairie Ecologist 
Very interesting, it’s always fascinating how different but very closely related species in different habitats are valued. In the UK our ragwort (Senecio jacobea) is regarded as a problem because of its toxicity to livestock, although it is an excellent food source for pollinators. Fortunately it only becomes a problem in poorly managed grasslands, but it can be very nasty if ingested by ponies and horses. Glad to see your ragwort is so valuable to wildlife.
Mike,
Ragwort isn’t EVERYONE’s favorite plant here either, though I think those who don’t care for it as much see it tend to view it as a weedy plant rather than an actual problem. I’ve not heard of toxicity issues with livestock with our species, but I wouldn’t be surprised if that’s a potential issue here. I agree – it’s always interesting to compare notes between continents. Thanks for chiming in!
Very much agreed Chris! They are like the sun on the prairie in late spring. I also get a sense about the types of pollinators on the prairie in a given year. I generally don’t notice many larger bees foraging on them much (e.g. Of the size of honeybees or larger). What’s your experience?
Patrick, I think you’re right. Mainly smaller pollinators, with the possible exception of some fairly large butterflies. I’m trying to remember, but can’t recall ever seeing bumblebees on ragwort…
I have Senecio pauperculus blooming for the first time in my seed garden. I also have seedlings of Senecio aurea. Your blog made me look up the species description for S. pauperculus and S. aurea again. I was afraid I had gone through the effort of growing plugs and planting them only for the plants to die this year. I am glad I discovered that unlike Senecio plattenensis, both S. pauperculus and S. aurea are perennial. phew
I recently visited an area where I planted plugs of Carex crawei and Carex tetanica in an established restoration. I could not believe the small size of the plants. They were much bigger when I had initially planted them. I could only find one small pair of leaf blades if I could even distinguish the plants from other species in the restoration. In contrast, the plants in my seed garden are robust. It is amazing how much difference competition and a limitation on nutrients affects the growth of plants. I expect the plants in the restoration will adjust and grow larger over time. In the mean time my seed garden plants will be producing lots of healthy seed for sowing. I really think the best use of expensive plugs is planting in a seed garden. The relatively large quantity of healthy seed that results is a better cost trade-off for establishing species in a restoration.
James
Thanks Chris, I am glad I came across this post, since I bought a few of these at the Nebraska Statewide Arboretum, and didn’t realize they are biennials. I now know which spot I am going to put them.