yerba de peo
Porophyllum leiocarpum (Urb.) Rydb.
Yerba de peo has a distinctive combination of broad, thin leaves and elongated flower heads. Johnson’s monograph describes an upright annual that branches above, with smooth green or purplish stems that may have a bluish bloom. The leaves can be opposite or alternate, and each is carried on a visible stalk. R. R. Johnson, 1969: Monograph of Porophyllum
Botanical name
Kew accepts Porophyllum leiocarpum (Urb.) Rydb.; Porophyllum macrocephalum var. leiocarpum Urb. is its homotypic synonym. Kew POWO: Porophyllum leiocarpum
Recognizing the plant
Leaf blades are oval, usually one to four centimetres long, with rounded tips and nearly smooth to wavy margins. Oblong glands sit in the shallow marginal notches and at the tip. Solitary heads stand at branch ends on slightly club-shaped stalks. Five narrow, green, purple-tinged bracts enclose thirty or more florets. The slender corollas are purple to olive green, and the smooth dry fruits carry straw-coloured to brown bristles. R. R. Johnson, 1969: Monograph of Porophyllum
Bloom window
Puerto Rico and South American populations treated by Johnson
The monograph reports flowering throughout the year across its treatment area. R. R. Johnson, 1969: Monograph of Porophyllum
Native range
Kew currently lists Puerto Rico, Venezuela and southeastern Brazil, specifically São Paulo, as native areas, chiefly in seasonally dry tropical conditions. Johnson’s older monograph interpreted the South American coastal populations as introduced; the current native-range statement here follows Kew. Kew POWO: Porophyllum leiocarpumR. R. Johnson, 1969: Monograph of Porophyllum
Botanical sources
Reviewed 2026-10-11. Seasonal development varies with location and growing conditions.