Wednesday, April 15, 2015

April Winter Annuals

My artificial barrens in a pot continues to evolve.  Originally planted in the container were Draba cuneifolia, Draba reptans, and Leavenworthia unifloraDraba reptans persists in small numbers and is hardly noticeable.  Draba cuneifolia and Leavenworthia uniflora aggressively compete for dominance of the container.  Since its creation, no two seasons in this container have been the same.

In 2013, Leavenworthia uniflora dominated the container.  Last year there was a fairly even mix of Draba cuneifolia and Leavenworthia.  This year the Draba cuneifolia is definitely in control.  Draba flower stalks form a miniature forest.

A loose cluster of flowers forms atop the stalk.  These plants are just beginning to bloom.  The flower spike will continue to enlarge and the immature buds seen in the center of the cluster will be brought into position to open.

A number of these small bees were busy visiting the Draba flowers.

Wild Draba cuneifolia plants are also doing well this year.

It’s unusual for the plants on the barrens to grow this large.  I’m certain that their growth patterns are influenced by weather conditions, but I don’t know if it was spending several weeks buried by snow or the excessive rainfall during the last six weeks or some other factor that is responsible for the impressive growth this year.

Draba reptans is also performing above expectations this year.  This plant toppled over, but that won’t stop it from producing a good crop of seeds.  Total height, or length, of this plant is not much over an inch, so it didn’t have far to topple.

Draba reptans is similar in appearance, but smaller than Draba cuneifolia.  One characteristic that separates the two is the hairiness of the flower stalk.  The stalk on reptans is practically hairless, while the cuneifolia stalk has a fuzzy hairiness along its entire length.

Drabas and Leavenworthias are blooming side-by-side in the container barrens.  Draba cuneifiolia has a shallow indentation at the end of each of the four petals.  Leavenworthia petals are all well rounded.  A couple of non-native Draba verna have also managed to invade the container.  Seen in the lower right of the photo, Draba verna petals are split almost in two, so the flower appears to have eight petals instead of four.

This year’s Leavenworthia plants are quite tiny and have only a single flower stalk.  I’m afraid they couldn’t compete with the rapid early growth of the Drabas.

Contrary to what I’ve noticed in past years, the Leavenworthia growing on the barrens are much more robust than those in the container.

Most of the barrens grown specimens are producing multiple flower stalks.  The seed produced from these should be a definite boost to future generations.

The Draba cuneifolia in the container are going to make a tremendous amount of seed.  I’ll collect as much as I can and scatter it out on the same barrens from which I originally gathered the seed for this container collection.  If my original removal of seed from the barrens resulted in a diminished population of Draba, I’m sure my replacement of seed has more than made up for the loss.

The container plants are producing so much seed that I’m now finding Draba cuneifolia growing in the cracks of the concrete apron outside my barn door.  I love it when a rare plant begins to behave like a weed.

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