April Nature Almanac: Early Easter Daisies Finally Emerge from their Winter Blanket
by Stephen Jones, with Ruth Carol Cushman and Scott Severs
April 2023
During the darkest days of winter, we've always had early blooming Easter daisies to look forward to.
Cushions of tightly-packed, leathery leaves help the Easter daisies conserve moisture. Photo by Stephen Jones.
Some years, a few have begun unfurling on sun-warmed shales and limestones in the foothills a few days before Thanksgiving. By Christmas, we could usually count on finding their white and yellow flowers sprinkled across these rocky slopes, assuring us that the world was, indeed, turning toward brighter days.
But not this year. When we hiked up to our favorite sites in late November, they were buried under a foot of snow. By late December, temperatures had plunged to 18 degrees below zero, and the few tiny plants we could find remained dormant, with their flower buds just barely noticeable.
January and February seemed much the same, with most of the plants still nestled under remaining snows as overnight temperatures plummeted into the negative teens.
Finally, toward the end of February, the snows melted away, and the little daisies put on a show unlike anything we'd ever seen. As we stood on one sun-warmed limestone slope in a foothills canyon, we could see dozens of fist-sized plants blooming all around us. Some barely peered out of cracks in the rock; others sported 30 or more delicate blossoms.
Like many of the rest of us, they had holed up in the snow and cold for weeks, waiting out one of the most persistently frigid winters in recent memory.
Growing on barren shales and limestones protects early Easter daisies from competition. Their long taproots enable them to access water pockets and soil nutrients stored deep in the rock. Photo by Stephen Jones.
Early Easter daisies (Townsendia exscapa and T. hookeri) are built to survive in dry, rocky environments. With long taproots probing down into cracks in calcium-rich limestones, they're able to extract water and nutrients that are inaccessible to most other plants. Early blooming helps them avoid competition for sunlight and pollinators.
This spring, the blooming of these tenacious little daisies seemed to coincide with the emergence of European honeybees. The slender proboscis of bees, small flies, beetles, and butterflies enables them to access nectaries in the tiny yellow disk flowers. The more prominent white ray flowers are infertile, serving only to attract, but not nourish, potential pollinators.
Early Easter daisies seem particularly popular with European honeybees, who sip nectar from their tiny yellow disk flowers during the depths of winter. Photo by Stephen Jones.
Around Easter, the bright yellow flowers of another hearty and much rarer shale specialist will begin to ornament foothills slopes north of Boulder. Bell's twinpod (Physaria bellii), a unique mustard found only on shales in the Front Range foothills of northern Colorado and southern Wyoming, also uses a deep taproot to anchor itself to these friable (easily crumbled) rocks and extract water from below the surface.
Look for their succulent green rosettes and circles of yellow blooms on the nearly black, 100-million-year-old Pierre shales on the east side of US 36. Later in the month, these rare mustards will be joined by the white and magenta blossoms of pioneering locoweeds (Oxytropis sp.).
Bell's twinpods grow only on shale surfaces of the Front Range foothills of northern Colorado and southern Wyoming. Their green rosettes are visible right now along US 36 north of Boulder, and their rosettes of yellow flowers should begin appearing by the end of April. Photo by Stephen Jones.
Though shale and limestone environments may appear bare and even forbidding to us, they provide niches for some of our most exquisite wildflowers. Clam and oyster fossils embedded in these rocks remind us that our world is forever transforming. Bright blossoms scattered across the barren ground reassure us that even during the coldest, darkest times, hope and renewal are on the way.
This column is dedicated to the memory of Nancy Dawson, who revelled each spring in the appearance of our first wildflowers.
Other April Events
Bald Eagle chicks have hatched on several nests, and Osprey pairs have just recently arrived on nesting platforms at Sawhill Ponds, Boulder Reservoir, and Rogers Grove in Longmont.
Mountain Bluebirds arrived by early March, and they, along with Western Bluebirds, have begun establishing nests in tree cavities along the foothills.
Look for snow white sand lilies (Leucocrinum montanum) and bright magenta Lambert's locoweed (Oxytropis lambertii) on south-facing slopes of foothills canyons. Bright yellow Nuttall's violets (Viola nuttallii) also bloom in these sun-warmed locations. Lavender pasqueflowers (Anemone patens) unfurl in rocky areas shaded by ponderosa pines.
Mink young begin to peer from dens located in rock piles, brush piles, and soft embankments along Boulder and Saint Vrain creeks.