Hairy Yerba Santa

eriodictyon trichocalyx

Hairy Yerba Santa (Eriodictyon trichocalyx) is a resilient, evergreen shrub native to the arid mountains and foothills of Southern California and Baja California. Belonging to the borage family, this woody perennial is famous for its heavily textured, aromatic foliage and sticky, resinous leaves. Historically revered by Native American tribes and early Spanish settlers, who dubbed it the 'holy herb' (Yerba Santa), it has a rich ethnobotanical history of medicinal use, particularly for treating respiratory ailments. In the chaparral ecosystem, Hairy Yerba Santa serves as a vital pioneer species, readily colonizing disturbed soils and burn areas to help stabilize the ground after wildfires while providing sustenance to local fauna. Discover and identify species like Hairy Yerba Santa with the Snappit app.

Habitat: Typically found on dry, sunny slopes and ridges in chaparral, coastal sage scrub, and yellow pine forest communities.

Appearance

This woody shrub typically grows between 60 to 200 centimeters tall, forming dense mounds of dark green, leathery foliage. Its lance-shaped leaves are highly distinctive, featuring deeply set veins, finely serrated margins, and a sticky coating of shiny resin on the upper surface, while the undersides are blanketed in a dense mat of white, woolly hairs. From spring to early summer, the plant produces dense, branching clusters of small, tubular flowers that range in color from pale lavender to white, surrounded by fuzzy, hair-covered calyces.

KingdomPlantaePhylumTracheophytaClassMagnoliopsidaOrderBoraginalesFamilyBoraginaceaeGenusEriodictyon

Hairy Yerba Santa

Interesting facts

Spanish missionaries were so impressed by the plant's ability to soothe coughs and respiratory issues that they named it 'Yerba Santa', meaning 'Holy Herb'.

The leaves of Hairy Yerba Santa contain eriodictyol, a compound that can temporarily mask bitter tastes, which led to its historical use in flavoring bitter medicines.

The sticky resin on the leaves was historically chewed like chewing gum by indigenous peoples to stave off thirst in dry Mediterranean climates.

Special abilities

The undersides of the leaves are covered in a dense layer of interlocking white hairs called trichomes, which trap a micro-layer of humid air and reduce water loss through transpiration.

The upper surfaces of the leaves secrete a thick, sticky resin that acts as a natural sunblock and prevents parching desert winds from drying out vital tissues.

This species possesses underground rhizomes that survive intense wildfires, allowing it to quickly resprout and dominate cleared landscapes post-fire.