Adenostoma is a genus of shrubs in the Rose family (Rosaceae) containing only two species, chamise (Adenostoma fasciculatum) and redshanks (Adenostoma sparsifolium). Both are native to the Californias.
The plants grow in a habit of shrubs to small trees, and the stem is more or less resinous.[1] Both species in this genus feature stiff, linear leaves arranged alternately or in clusters along stems with shredding bark. Flowers form on a panicle, are cream to white and, as in all members of the rose family, have hypanthia. The fruit is an achene. Chromosome number is 2n = 18.[1]
Both species are native to coastal California and Baja California. Adenostoma fasciculatum is also native to California in the Sierra Nevada.[2] They are found in plant communities and sub-ecoregions of the California chaparral and woodlands ecoregion.
Phylogenetic analysis places Adenostoma closest to Chamaebatiaria and Sorbaria, and suggests tentative placement in the subfamily Spiraeoideae, tribe Sorbarieae.[3] The name Adenostoma comes from Greek, meaning "glandular mouth," referring to the hypanthium ring gland.