Daily Archives: April 24, 2012

Introducing Oenothera speciosa

Last month, I had one of those conversations that makes you want to dig around in reference material for a few days. Specifically, I was showing plants at a show to a gentleman who was unfamiliar with carnivores, and he took a particular shine to a primrose butterwort (Pinguicula primuliflora). The name confused him, though: “I know primroses, and that’s no primrose. Why do they call them that?”

At the time, I explained that this was a great example of why Latin binomial nomenclature is so important: I explained that a lot of plants receive the common name “primrose”, but that he needed the Latin names to help distinguish between them. After he left, though, I kept asking “Why ‘primrose’?” I was familiar with the color primrose, which could fit some varieties of plant with that color of flower. However, North Texas has at least two varieties of plants called “primrose”, one with bright canary yellow blooms and one with bright pink blooms. So what was the connection?

I learned later that the term “primrose” refers alternately to the first-blooming flowers of the spring and to flowers that close in the morning and open in the evening. This works, except for the flowers that buck that trend. Oenothera speciosa, the pink evening primrose, does a great job of waggling various appendages at pedantics, as it pretty much opens if and when it feels like.

Oenothera speciosa

O. speciosa is quite the common wildflower in Texas, especially right now, and it usually cheerfully blooms when most other wildflowers have died off for the summer. It grows just about everywhere, but does best in open areas with lots of sun and protection from excessive mowing. As such, it’s found along highways, drainage ditches, vacant lots, and back alleys. It’s usually not invasive, so most people don’t notice it save when its blooms pop in the middle of an otherwise monotonous field.

Oenothera speciosa, the pink evening primrose

Now, you may notice that the common name for this primrose includes the word “pink”, but this photo shows precious little. That’s a bit of a surprise. O. speciosa blooms tend to be rather reactive to ultraviolet light, and shining a UV flashlight on one in the dark reveals that it tends to fluoresce white-yellow. The upshot is that this photo was taken with a new camera after my old one finally cacked it about two weeks ago, and apparently this new camera is much, much more sensitive to UV than the previous one. This may not be much, but get ready for some interesting projects in the next few weeks.