''Petrophytum'' ( orth. var. ''Petrophyton'') is a small genus of plants in the

rose family Rosaceae (), the rose family, is a medium-sized family of flowering plants that includes 4,828 known species in 91 genera. The name is derived from the type genus ''Rosa''. Among the most species-rich genera are '' Alchemilla'' (270), ''Sorbus ...

known as the rock spiraeas or rockmats. These are low mat-forming shrubs which send up erect stems bearing spike inflorescences of flowers. The brushy flowers are white and have many

stamen The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filame ...

s and hairy, thready

pistil Gynoecium (; ) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl of a flower; it consists of (one or more) ''pistils'' ...

s. Rockmats are native to western North America. Species: *'' Petrophytum caespitosum'' — mat rock spiraea *'' Petrophytum cinerascens'' — halfshrub rockmat, Chelan rockmat *'' Petrophytum hendersonii'' — Olympic Mountain rockmat

References

External links

Jepson Manual TreatmentUSDA Plants ProfileThe Plant List: A Working List of All Plant Species
Spiraeeae Rosaceae genera {{amygdaloideae-stub