Natural History Wanderings

Yosemite National Park has posted the following wildflower report on their websites:

“April showers bring May flowers—as the cliché goes—and, in this case, Mother Nature generously watered the Sierra Nevada’s foothill wildflowers. Abundant blooms greet visitors traversing along the Merced River Canyon, where Highway 140 snakes alongside the rolling river. Traveling from Mariposa to El Portal can provide a variety of the late spring’s flowers at Yosemite’s lowest elevations at the El Portal administrative site at approximately 1,800 feet.

Most noticeable along the roadsides right now is the bright yellow common madia (Madia elegans)—which flowers in the spring and again in the summer. Its disk florets (with eight to 16 rays) can be colored a solid yellow or have a maroon blotch at the base. Find fields of madia along some of the hillsides.

Brand new along the 140 corridor are mountain jewelflower (Streptanthus tortuosus), pretty face (Triteleia ixoides spp. anilina), Chinese house (Collinsia heterophyla), blazing star (Mentzelia crocea), twining brodiaea (Dichelostemma volubile), paper-flowered onion (Allium hyalinum), and Western wallflower (Erysimum capitatum). Several lupine varieties display their colors, including bush lupine (Lupinus albifrons), miniature lupine (Lupinus bicolor) and white-flowered lupine (Lupinus microcarpus). Approximately 26 of the 70 species of lupines in California can be found in Yosemite.”

“The fleshy leaves of brightly colored stonecrop rise of out steep rock crevices often dark with dew. Sierra stonecrop (Sedum obtusatum) is the most common stonecrop in Yosemite—first described from specimens collected near Vernal Fall and common in damp crevices along the Giant Staircase. Its thick green leaves form a rosette base with erect reddish stems that are topped by perfect yellow flowers. With approximately 500 stonecrop species in the world, others in Yosemite include the Pacific stonecrop (Sedum spathulifoloium), narrow-petaled stonecrop (Sedum lanceolatum), and rosewort (Sedum roseum) at the highest elevations.

Standing tall are thistles, just starting to rise up on the Sierra landscape. Note that Yosemite has three native thistles: Anderson’s (Cirsium andersonii), California (Cirsium occidentale), and alpine thistle (Cirsium scariosum). What’s a good way to tell the difference between a native and a non-native thistle? No thistles native to Yosemite have wings or ridges on the stems. Beware that the pink Anderson’s thistle and California thistle look alike and can be easily confused with the invasive bull thistle (Cirsium vulgare).

Applegate’s paintbrush (Castilleja applegatei), which attracts your eye with its orangey-red splash, has a mysterious side to it that’s not so visible. In order to feed itself, paintbrush and a variety of plants are parasitic on other plant matter. Paintbrush, for example, is partially parasitic on the roots of other plants. Identify paintbrush by the petals that fuse into white or yellow tubes extending from clusters of bracts that are typically red.

Earlier blooms that are still standing include the pale yellow many-flowered monkeyflowers (Mimulus floribundus), bright yellow foothill pseudobahia (Pseudobahia heermannii), pastel baby blue-eyes (Nemophila menziesii) , bright pink red maids (Calandrinia ciliata), and intensely-colored blue dicks (Dichelostemma capitatum). Common lomatium (Lomatium utriculatum) adds a yellow hue to grassy slopes, too, displaying 5- to 13-rayed umbels—flat-topped flower clusters to which the individual flower stalks all arise near one point on the main stem. Also, continue to look also for the yellow heads of golden yarrow (Eriophyllum confertiflorum), which is not a true yarrow but is in the woolly sunflower genus. Tufted poppies (Eschscholzia ceaspitosa), a favorite California flower, did not have a showy display this year, unfortunately, due to heavy spring rains. Find poppies at lower elevations than Yosemite offers.

While looking for spring flora, do not overlook the area’s flowering shrubs and trees. The Western redbud (Cercis occidentalis), which first blossomed in April, adds a magenta hue to the Sierra green hillsides. The vibrant redbuds, in May, transition from flowers to leaves. Decidious trees, like the redbud, flower before or just as leaves appear. This botanical sequence—flowers before leaves—is believed to offer easier access to pollinators to locate the flowers.

View the last of the bell-shaped flowers of the Mariposa manzanita (Arctostaphylos viscida ssp. Mariposa). Yosemite botanists enthusiastically indicate that the Mariposa manzanita, a subspecies of the whiteleaf manzanita, has displayed one of its best years due to the surge of early spring’s moisture. Typically a February bloomer, the manzanita’s pink flowers show in abundance against dark red bark.

For the moderately showy ceanothus shrub, California could be the center of diversity. In Yosemite’s lowest elevations, look for the white or pale blue flower umbels of buck brush (Ceanothus cuneatus) with its rigid, divergent, grayish branches with opposite leaves on spur-like branchlets in the chaparral and mixed conifer zones. Buck brush is named cuneatus for good reason because cuneatus means wedge shaped—referring to the shape of the leaves. With buck brush growing abundantly, look more closely for deer brush (Ceanothus integerrimus), distinguished by its elongated flower panicles and opposite leaves. Deer brush can be seen at 2,000 feet but typically takes root at about 4,000-foot elevation in the submontane chaparral.

What else might you see on the Sierra wildflower landscape? It’s possible to find several pretty plants that just don’t belong—in other words they are non-natives. Dead nettle (Lamium amplexicaule) and American vetch (Vicia Americana), for example, are both a showy purple that claim attention. Dead nettle’s purplish-red whorled flowers might remind you of a native lupine. Vetch’s clawed petals have wings that adhere to the keel for more than half their length on climbing, vinelike stems. Like many non-natives, these invasive plants establish themselves around disturbed areas, such as like roadsides and developed areas on hillsides in the El Portal area.

Late spring is an excellent time to plan a hike along the Hite Cove trail, located on the Sierra National Forest along Highway 140 seven miles before the Yosemite National Park entrance. Find the Hite Cove trailhead behind the old Savage’s Trading Post location, where a historic sign still marks the site now known for its typical dense carpet of spring flowers. The 4.5-mile trail (one way) follows the south fork of the Merced River. In early May, look for fairy lantern (Calochortus albus), owl’s clover (Castilleja densifora), woodland star (Lithophragma affine) and blazing star (Mentzelia crocea).

In Yosemite Valley, waterfalls flow greater than wildflowers grow; however, Pacific dogwoods (Cornus nuttallii) begin to bud.

A note of warning: March brought the Yosemite area heavy snow that broke tree tops and limbs at unusually low elevations. Beware of damaged trees above you that could fail in the next stiff breeze, or any time, as you enjoy the spring wildflower display.”