Photo of the Week – July 24, 2014

I’m definitely a better close-up photographer than a landscape photographer.  Part of that is just the way my mind works – I tend to look down instead of up when I walk around a prairie.  I can always find an interesting flower or insect to photograph when the light is good for photography, but I have a harder time constructing an interesting composition or the larger landscape.  There are so many things to think about with landscape photos; foreground, background, sky, leading lines – or not… ack!  As a result, when the light is pretty, I usually look around for something small and interesting.

However, there are days and places where even I can take good landscape photos, and yesterday was a perfect example.  I got up early enough to drive the 35 minutes between my house and our Platte River Prairies before sunrise.  I’d been eyeing the prolific blooming of fourpoint evening primrose (Oenothera rhombipetala) in the sandhills on the edge of the river valley.  It’s been several years since we’ve seen a big explosion of primrose flowers, and this year’s seemed even more spectacular than the last one.

At the first glimpse of the sun, I knew it was a going to be good morning.  The Nature Conservancy's Platte River Prairies, Nebraska.

At the first glimpse of the sun, I knew it was a going to be good morning. The Nature Conservancy’s Platte River Prairies, Nebraska.

Before the sun popped over the horizon, I wandered around and pretended there was enough light to make good photographs, knowing that I was only shooting because digital photos are free…  Once the sun appeared, though, things got serious.

Goodness gracious

Fourpoint evening primroses all the way to the horizon.

How can you not take great photos when you’re surrounded by big yellow flowers, the sky is filled with gorgeous clouds, and the light is coming in low and warm?  I scurried around with my camera and tripod, trying composition after composition, and liking each one more than the one previous.  The biggest difficulty was trying to come up with photographs that really showed the size, scope, and abundance of the flowers in real life.  My wide angle lens felt insufficiently wide for the scene.

More primoses

More primroses

I ended up with hundreds of photographs of primroses.  I stayed up late last night trying to go through them and pick out a handful to use for today’s post.  I felt good when I narrowed them down to 20, but that’s way too many for one blog post – especially when they all look about the same…  I went to sleep dreaming about fields of yellow.




This morning, I managed to narrow it down to the photos you see here, but it was painful.  Stop by sometime and I’ll show you the others…!

The ecology behind the photos

So why are there so many fourpoint evening primroses this year?  Across the sandy prairies of Nebraska, fourpoint primrose is having a good year, though maybe not as good of a year as sunflowers had last year.  Fourpoint evening primroses are biennial plants, so they typically germinate and form a rosette (just leaves, no vertical stems) in their first year of life and then bloom and die in their second – leaving behind many thousands of seeds to kickstart the next generation.  They are not strong competitors with grasses, so fourpoint primroses can’t germinate in years when the vegetation is dense.

Ok, I did take a FEW close-ups too.  Every day, the primose opens a new row of buds as the previous days' flowers wilt.  Judging by the unopened buds at the tops of these flowers, we'll be seeing yellow for a while yet.

Ok, I did take a FEW close-ups too. Every day, the primrose opens a new row of buds as the previous days’ flowers wilt. Judging by the unopened buds at the tops of these flowers, we’ll be seeing yellow for a while yet.

The year 2012 was the most severe one-year drought on record for our area.  That weakened the grasses in our sandhills prairie.  Coincidentally, however, we also burned and grazed those hills in 2012.  As a result, by July, the hills were covered in very short brown grass and not much else because the plants had given up and gone dormant in the face of intense grazing and no soil moisture.  It looked pretty tough.  We had better moisture in 2013, and the grasses started their slow recovery, but there was a lot of open space between them that was colonized by annual plants (such as annual sunflowers).  However, another major colonizer was fourpoint evening primrose.  Unlike the sunflowers, however, the primrose plants didn’t bloom last year – they bided their time and soaked in the sun, water, and nutrients made available by the low density of plants surrounding them.  Then, this summer – 2 years after the drought – they made their move and exploded onto the scene with resplendent glory.  Or something.  Anyway, they sure are pretty.

We’ve had lots of rain this year, and we’re not grazing those sandhills this year, so the grass is getting pretty dense beneath the primrose flowers.  That means we won’t see many primroses next year or the year after.  That’s ok, they’ll wait – and when the time is right, they’ll be back.


Flowers of the Night

Not many plants wait for the sun to go down before they open their flowers…

Missouri evening primrose in tallgrass prairie at Camp Cornhusker (Boy Scouts of America) near Humboldt, Nebraska

Missouri evening primrose in tallgrass prairie at Camp Cornhusker (Boy Scouts of America) near Humboldt, Nebraska.  This photo was taken half an hour after sunset in early June.  Light for the image was provided by both the afterglow of sunset and the rising moon.

Like other evening primroses, Missouri evening primrose blooms overnight rather than during the day.  The plants can produce multiple flowers, which open at about sunset, but each individual flower blooms for only a single night.  The pollen grains of evening primroses are attached to each other by very thin elastic threads, which apparently stick very well to sphinx moths, their primary pollinators.  Night-flying bees also feed on evening primroses but are not thought to be effective carriers of pollen from one flower to another.


A closer view of a Missouri evening primrose plant.

As some of you more botanically-aware readers surely know, the contemporary name for this plant is Oenothera macrocarpa, or bigfruit evening primrose (macro = big, carpa = fruit).  Many of us, however, still refer to it as Missouri evening primrose because it used to be Oenothera missouriensis, and I’m choosing not to break that habit.  So there.

Regardless, it is a beautiful prairie wildflower that typically grows less than a foot tall and has large yellow flowers.  Its four-petaled blossoms turn into very distinctive four-winged seed pods, which are often used in floral displays (there happens to be a glass vase full of them on my dining room table right now!)  Missouri evening primrose has a long taproot and usually grows best in soils with relatively little organic matter.

Most flowers bloom during the day, taking advantage of the numerous pollinators that fly around when the sun is high in the sky.  That’s a fine thing to do, but I can appreciate the strategy of evening primroses.  Why fight the crowds when you can monopolize the attention of a few specialized pollinators during the off hours?