I was at the Niobrara Valley Preserve this week. My son John and I went up for a kayaking trip, as well as for some work. Thursday evening, we went looking for bison, driving through the 10,000 acre east bison pasture. As the sun was going down, we hadn’t yet found any bison, but the prairie was gorgeous and we were enjoying the drive. We were near the far corner of the pasture when we spotted the primroses.
Fourpoint evening primroses (Oenothera rhombipetala) are having a good summer. Two years of abundant rain probably help with that – the plants are biennials, so they germinate one year and bloom the next, before dying at the end of their second season. Lots of rain means that a big number of seeds can successfully germinate and grow because moisture isn’t limiting. However, the huge patch John and I came across was influenced by more than just rain.
The primrose patch we found was hundreds of acres of almost solid yellow, and there was a distinct border to the patch. As soon as I saw it, I recognized it as the 2017 prescribed burn unit, which was burned in the spring of 2017 and then grazed by bison very intensively that year and again in 2018. It is recovering from that intensive disturbance, but the grasses are still weakened from that grazing impact, meaning greatly reduced competition for new seedlings of fourpoint evening primrose. As a result, some germinated in 2017 and bloomed in 2018, but many more germinated in 2018 and bloomed this year.
As the sun sank, I scurried around with my camera, trying to capture the incredible scene, while John patiently waited and wandered on his own. The next morning, I snuck out while he slept and caught the sunrise at the same location. In this post, I’m including just a few of the many many photos I took during those two short periods of time.
Today, we took a group of visitors out to see the same primrose patch. They were appropriately impressed… It’s always nice when prairie resilience displays itself in such an aesthetically pleasing way!
The Prairie Ecologist 
Thank you for remembering to send me your interesting missives. I have an evening primrose or two growing wild in my garden, but they have red stems and leaves.
You make me want to head back.
Hi, Chris!
My Mom would have loved this. She did not know many wildflowers. So, she would call most things “primroses” and I would correct her. One day, we were driving near Grove Lake and I said, “Look at those yellow flowers, Mia”. She was a bit weary of being corrected by then. ;) I said, “Guess what? Those are primroses!” And we stopped so I could take photos.
Cheers!
Nice. Doesn’t matter what people call them, as long as they appreciate them! Cool story, thank you.
Thanks, Chris! She could spot wild asparagus at a quarter mile. :) Back before all of the roads were “fixed” and all of the trees, shrubs and flowers were ripped out.
Thank you for sharing this incredible beauty with the rest of us. I so appreciate your photos, comments, and information.
Beautiful!
I will have to visit the preserve soon. If they got the rain there last night that we did here, it may be a while before the roads are open. I’ve been aware for a long time of the benefits derived from controlled burning and intensive grazing, but hadn’t thought to put them together. What a spectacular outcome. I also visited your square meter project. What a great way to showcase prairie diversity! How often did you visit your square meter?
Thank you. I’m glad you liked the square meter project. I think I visited 46 times during the year, but that was much more concentrated during May through October, of course. There were days when I went twice a day, but usually a few times a week.
They have been thick in the Rolling Plains area of West Texas this year, also, due to very unusual spring rain amounts, I suspect. Lovely pictures.
Wow! That is beautiful. They are amazing one at a time. The patch is fantastic.
Chris, thanks for sharing your encounter. I have never seen such a display of yellow except for sunflowers.
Beautiful pictures!
I keep discovering new species of primroses, and now I can add these to the list. They’re beautiful, and the sight of them covering the land must have been spectacular. A prescribed burn at one of our refuges a few years ago resulted in a similar burst of growth; in that case, it was acres of spider lilies (Hymenocallis liriosme) that appeared. Even the fishermen heading down to the boat ramp would pull over to look.