The Attractive Wallflowers, Genus Erysimum

western or sanddune wallflower, Erysimum capitatum

Spring and early summer is when most members of the cabbage and mustard plant family, Brassicaceae, flower. There are a lot of them--774 species in North America. They share the "cross-like" flower structure: four petals at right angles, and the flowers tend to be yellow or white, so they can be hard to tell apart (hint: use seed pod shape.) But one genus that I quickly learned to distinguish is the wallflower, Erysimum. Wallflowers have a compact shape, large flowers (for a mustard), and orangy flowers that set them apart. 

Plant Story--Sweet Alyssum, Lobularia maritima

Sweet alyssum is a pretty plant with white to purple flowers, frequently planted in gardens. 

sweet alyssum, Lobularia maritima

It is in the mustard and cabbage family, Brassicaceae, and has the typical simple, cross-shaped flowers. The scientific name is Lobularia maritima, Lobularia from the Latin lobulus, a small pod, and maritima means of the sea, as in maritime. It is native to southern Europe and into west Asia. In places without a winter, it may be perennial, but across North America it is grown as an annual. Seed it in just before the end of spring frosts. Sweet alyssum isn't picky about soil, water, or exposure, (though it doesn't grow well in deep shade or soggy soil), making it very easy to grow. It flowers quickly, will continue to flower all summer, and has a lovely fragrance (if you get your nose down close to the flowers). Under many conditions sweet alyssum will self-sow, scattering seeds that produce plants in subsequent years. 

Plant Story--A Small Weedy Alyssum, Alyssum simplex

Wanting to get out as the weather warms, I frequently walk Colorado foothills trails in April and May. Conspicuous there is wild alyssum, Alyssum simplex. 

All the little yellow flowers are wild alyssum, Alyssum simplex

Visiting Northern Colorado--Horsetooth Mountain Park in Spring Snow

Horsetooth Mountain Park trail, in falling snow

April 28. I needed to check out the trailside plants of Horsetooth Mountain Park, on the west side of Fort Collins Colorado, for a plant hike I was going to lead the next weekend.

When I got there it was snowing. Lightly, mixed with sleet, but persistently.

One of the things I learned as a prairie ecologist: "do it now, the weather later may be worse."

Hiking out in the sleet/snow was cool but not unpleasant and I knew the weather forecast was for snow for the next three days. Out I went!