Osyris

Osyris is a genus of flowering plants in the family Santalaceae. Members are root hemiparasites that attach to the roots of host plants via haustoria, obtaining water and minerals while still performing photosynthesis. This parasitic strategy allows Osyris plants to inhabit relatively dry or nutrient-poor environments where they can access hosts such as trees and shrubs.

The genus is native to the Old World, with species distributed across Africa, the Middle East, southern Europe, and parts of Asia. They are typically found in open woodlands, scrub, and rocky slopes where suitable host plants are available. Osyris alba is the best-known species and occurs in the Mediterranean region; other species occur in Africa and Asia.

In appearance, Osyris plants are usually evergreen shrubs or small trees with simple, often narrow leaves and small, inconspicuous flowers. The genus is not widely cultivated and is of particular interest to botanists studying parasitic plant strategies rather than for ornamental horticulture.

Taxonomically, Osyris has been placed in the Santalaceae family in modern classifications. Its classification has varied in older systems, but current treatments generally recognize Osyris as a distinct genus within Santalaceae. Conservation status varies by species and region, with some populations affected by habitat loss and ecological change.

Overall, Osyris represents a small group of parasitic flowering plants notable for their reliance on host plants while maintaining photosynthetic ability, and for their occurrence in the Mediterranean and broader Old World regions.