The Yosemite ferns, forests, and flowers are growing almost exclusively in glacial soil. Nearly all of the soil in the Park is rock-flour that was ground by glaciers, and in part distributed by them. Landslides and running water distributed most of the remainder.
The Park has an altitudinal range of nearly two miles, with them any climates, and consequently numerous varieties of flora. These are encouraged by varied life zones that result from combinations of sunny and shady mountain-sides, unevenly distributed moisture, and the different temperatures that prevail between the altitudes of three thousand and thirteen thousand feet.
Here and there in the Park wild flowers may be found in bloom every month of the year. Among the common flowers of the middle and lower sections are seen the shooting-star, evening-primrose, tiger lily, yellow pond-lily, Mariposa lily, black-eyed Susan, lupine, paintbrush, yarrow, and snow-plant. There are violets, blue and red, a number of pentstemons, the lark-spur, golden-rod, several orchids, and the wild rose.
Many of the showy, crowded gardens of luxuriant wild-flower growths are in the moist fir forests. Among the tall flowers in these gardens are columbines, larkspurs, paintbrushes, lupines, and one of the lily families. The famous, fragrant Washington lily brightens the open woods; in places it grows to the height of eight feet.
The snow-plant is a curiosity and attracts by its brilliancy of color. The plant and bloom are blood-red, but this herb is as cold and rigid as an icicle. It is not a parasite, but is isolated and appears to hold itself aloof from all the world. When caught by late snows it makes a startling figure, but it does not grow up through the snow.
In the alpine heights are many healthy plants: the lovely arctic daisy, phlox, gentian, lupine, potentilla, harebell, mountain columbine, astragalus, and numerous other bright flowers. They grow in clusters and in large ragged gardens, and in places are low-growing and extremely dwarfed.
Besides its wild small plants and the blooming shrubbery the Park has a glorious wealth of tree blossom. The hemlocks, pines, firs, and spruces have a jeweled wealth of blue, purple, red, and yellow bloom.