CulénOtholobium glandulosum

Did you know?

• Culén is in the dictionary. The Royal Spanish Academy gives the word a Mapuche origin and defines the plant as a leguminous shrub native to Chile whose leaves, flowers and stem are taken as an infusion; the Dictionary of Americanisms notes that its leaves and flowers are infused for digestion^{[3, 4]}.

• Early Spanish chroniclers called it albahaquilla, "little basil"^[7]. In Spanish it is also hierba de San Agustín, "St Augustine's herb"^[4].

• In 1646 the Jesuit Alonso de Ovalle drew a small culén tree on his map of Chile for King Philip IV of Spain and labeled it a "very healthy plant"^[7].

• Carl Linnaeus named it Psoralea glandulosa in 1763. Botanists have since moved it twice: to Otholobium in 1990 and, in 2024, to a newly created genus, Grimolobium^{[1, 2]}.

• In 1782 the Chilean Jesuit naturalist Juan Ignacio Molina described the same plant as Psoralea lutea in his natural history of Chile^{[2, 7]}.

• In Chile today, street herb sellers, the yerbateros, often sell culén leaves ready-packed in tea bags^[7].

Origins and history

Culén is a shrub, usually up to about 3 m (10 ft) tall, that can also grow into a small tree^{[1, 4, 6, 9]}. Each leaf is made of three leaflets^[4], and the leaves and stems are coated with fine glandular hairs that give the plant its resinous feel^[5]. Its home is the western side of South America, from Peru and Bolivia through central and southern Chile^[1]. In Chile it grows in damp places and ravines from Coquimbo to Valdivia^{[6, 9]}.

The plant has a long paper trail. In 1646 the Jesuit Alonso de Ovalle put it on his map of Chile, and the French travelers Louis Feuillée and Amédée-François Frézier wrote about it in the early eighteenth century^[7]. Around 1767 the Jesuit Miguel de Olivares noted that drinking culén tea sharpens the appetite^[7]. Carl Linnaeus described it in 1763, in the second edition of his Species Plantarum, as Psoralea glandulosa^[1]. Nineteen years later the Chilean Jesuit naturalist Juan Ignacio Molina, in his 1782 natural history of Chile, called it Psoralea lutea^{[2, 7]}. In 1990 the botanist J.W. Grimes moved it to the genus Otholobium^[2]. In 2024 A.N. Egan and C.H. Stirton placed it in a new genus, Grimolobium, and Kew's Plants of the World Online now lists it under that name^[1].

Its everyday names are as varied as its botanical ones. In Chile and Peru it is culén, a word of Mapuche origin^[3]; it is also called hualhua or wallwa^[5], hierba de San Agustín^[4] and, in the words of early Spanish chroniclers, albahaquilla^[7]. The leaves, often with the flowers and stems, are steeped in hot water to make the tea for which it is best known^{[3, 4, 6]}, and the aromatic leaves have long served as a substitute for tea^{[6, 9]}. Culén goes into cool drinks as well: the young shoots make a refreshing chilled drink^[6], and in Chile the leaves flavor a traditional drink called aloja de culén^[9].

Traditional uses

Culén's best-known tradition is its tea, so familiar in Chile and Peru that Spanish-language dictionaries describe it^{[3, 4]}, and Chile's Ministry of Health includes culén in its official list of traditional herbal preparations^[8].

• A digestive tea

  The leaves, often with the flowers, are steeped in hot water and drunk as an infusion to support healthy digestion.*^{[3, 4, 6, 8]}

• Digestive comfort

  Chilean tradition takes culén tea for the stomach, and early accounts note that it sharpens the appetite. Culén supports digestive comfort.*^{[4, 7, 8]}

• Refreshing drinks

  Besides the hot tea, culén is made into cool drinks, from a chilled drink of the young shoots to Chile's traditional aloja de culén.^{[6, 9]}

Plant compounds

Culén's leaves and stems are coated with a resin made by tiny glandular hairs^[5]. The resin is rich in bakuchiol, a meroterpene^[5]. The plant also contains furanocoumarins, a group of plant compounds that includes psoralen^[5].