Plants of the Western Slope Jan. 17, 2018

By Evelyn Horn

Plants of the Western Slope Jan. 17, 2018 | Evelyn Horn, Plants of the Western Slope,

Photo by Al SneiderĀ© McCauley's buttercup

McCauley's Buttercup

The highway's dry and the scenery is magnificent! We've passed Montrose and ahead the San Juan mountains, gleam bright white against the clear blue sky. This volcanic range, known as the American Alps, is so jagged that it could well be from a child's drawing. I gaze at the impossible peaks of gleaming snow but I know that when it melts there will be wildflowers. And in my mind's eye I revisit the Native Plant Society's walk when we went to Yankee Boy Basin.

So many were plants that I'd met only in books, but then they became real. The pale Alp lily bending in the breeze, the deep magenta of the alpine fireweed sprawling over the lip of a trickling waterway, the ground-hugging dwarf clovers in white and lavender, broad stretches of Sibbaldia with its tiny yellow blossoms, Snowball saxifrage nestling against a dark rock and the whitish snapdragon-like flowers of James's snowlover. Walking along the path, Peggy Lyon pointed out a yellow patch of McCauley's buttercup, but buttercups are common with 2,000 species worldwide and nearly 20 on the Western Slope. They occur in alkaline ponds in the 'Dobies, in dry sagebrush areas and in our mountains. Most buttercups prefer cool damp sites and several are aquatic. The group or genus name, Ranunculus, is from Latin 'rana' probably for a frog since both frogs and flowers are often in wet sites. I've met a few white buttercups but most are yellow.

Peggy's remarks make me curious. The six-inch tall stems support inch-wide flowers of five shiny (buttered?) yellow petals with a dense cluster of yellow stamens in the center. But the leaves should have been dissected or at least lobed and these inch-long leaves are merely toothed near the tips. I notice that there are brownish blobs among the yellow blossoms ... they're unopened flowers! I take one bud and can separate out five, curled sepals -- they're completely covered with silky, dark hairs. Check a yellow blossom ... the underside is hairy too. During our Nevada years, I learned about such hairs: they protect the plant's breathing pores, insulate it from wind and cold (or heat), diffuse the intense solar radiation and reduce water loss in an arid climate. Here on the tundra most of the moisture is frozen most of the year.

I've learned since that marvelous day on the tundra, that my buttercup is named for the collector H. McCauley (1843-1913). It's restricted to the high mountains of Colorado and New Mexico. The proper botanical name is Ranunculus macauleyi.