Below Tueeulala Falls along the Wapama Trail, which follows the shoreline of Hetch Hetchy Reservoir (Yosemite National Park CA), are carpets of petite plants growing only a few centimeters tall – Sierra mock stonecrop (Sedella pumila).
The genus Sedella contains four species, all native to California and known as mock stonecrops, of which only one is not endemic. S pumila extends into Oregon. A synonym for S pumila is Parvisedum pumilum.
An annual, Sierra mock stonecrop has succulent, thread-like stems that are simple or branched near the base. The small, knobby, succulent leaves can be red, green or yellow in color. These sessile (no stalk) leaves are opposite near the base of the stem and alternate distally.
Sierra mock stonecrop flowers have five fleshy sepals fused at the base and five petals, also fused at the base. The petals are yellow, straw-colored or greenish marked with red. The ten stamens have yellow or reddish brown anthers and five pistils.
The Sierra mock stonecrop fruits are utricles – indehiscent (does not open at maturity to release the seed) structures containing one ribbed seed.
This member of the Stonecrop Family (Crassulaceae) is a plant of vernal pools and similar habitats as well as moist, rocky, gravelly flats composed of serpentine, limestone and volcanic soils between approximately 100 and 4,900 feet.
The species name, pumila, is Latin and means “dwarf”. The derivation of the genus name, Sedella, is less clear. It may, as some sources state, be associated with the town and municipality in Malaga, Southern Spain, by the same name. Or it could mean “a small Sedum” since “ella” is a Latin suffix indicating something diminutive. Mock stonecrops resemble miniature sedums.