Coleus barbatus, also known by the synonyms Plectranthus barbatus and incorrectly Coleus forskalaei (and other spellings of this epithet), is a tropical perennial plant related to the typical coleus species. It is known by the common name woolly plectranthus. It produces forskolin, an extract useful for pharmaceutical preparations and research in cell biology.
The Brazilian name is boldo brasileiro (pronounced [ˈbowdu bɾaziˈlejɾu]), or boldo gaúcho, as opposed to the Chilean true boldo; boldo-da-terra (pronounced [ˈbowdu dɐ ˈtɛʁɐ]); boldo-de-jardim (pronounced [ˈbowdu dʒi ʒaʁˈdʒĩ]); or tapete-de-Oxalá (pronounced [tɐˈpetʃi dʒoʃaˈla]; 'Oxalá's carpet', because of its velvety texture).
In the French Caribbean, it is called "doliprane" (from the brand name of a paracetamol-based drug) because of its uses as a painkiller in folk medicine.
It is a semi-succulent plant that grows as a subshrub to 1.5 m high by 1.5 m wide. The oppositely arranged leaves are relatively large with serrated leaf edges. Purple-blue flowers grow on upright racemose inflorescences that are up to 25 centimeters long.
Coleus barbatus was first described by Henry Cranke Andrews in 1810 as Plectranthus barbatus. It was transferred to Coleus by Bentham in 1830. Although Coleus was previously sunk into Plectranthus, the original binomial was revived in a major study of the subtribe Plectranthinae in 2019.
The distribution area extends from tropical Africa across the Arabian Peninsula to parts of South Asia and East Asia. It is native to Burundi, China South-Central, East Himalaya, Eritrea, Ethiopia, India, Kenya, Nepal, Oman, Rwanda, Saudi Arabia, Somalia, Sri Lanka, Sudan, Tanzania, Thailand, Uganda, Yemen and Zaïre.
Herbal teas made from Coleus barbatus contain rosmarinic acid and also flavonoid glucuronides and diterpenoids.
Forskolin, which derives its name from the incorrect binomial name of this plant, Coleus forskohlii, has been isolated from the roots.