Ivesia callida is a rare species of flowering plant, in the rose family, known by the common name Tahquitz mousetail. It is a small perennial herb which forms matted patches of hanging foliage on cliff faces. The leaves are strips of oval-shaped green leaflets. Each leaf is up to 7 centimeters long and has several pairs of hairy, glandular leaflets. The thin, green, hanging stems grow up to 15 centimeters long and bear an inflorescence of several flowers. Each flower has five hairy, pointed sepals and five round to oval white petals. The center of the flower contains twenty stamens with disc-shaped anthers and several pistils.

Ivesia callida
Conservation status
Critically Imperiled  (NatureServe)
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Clade:	Rosids
Order:	Rosales
Family:	Rosaceae
Genus:	Ivesia
Species:	I. callida
Binomial name
Ivesia callida (H.M.Hall) Rydb.

The plant is endemic to the San Jacinto Mountains of Riverside County, California, where it is known from only two occurrences. The plant grows in cracks and crevices of granite mountain cliffs. It was named for Tahquitz Rock, a rock formation in its endemic range. The rock formation was named for the Native American spirit Tahquitz.