Parentucellia viscosa

Taxonomy

• Kingdom: Plantae
• Clade: Tracheophytes → Angiosperms → Eudicots → Asterids
• Order: Lamiales
• Family: Orobanchaceae (formerly placed in Scrophulariaceae)
• Genus: Parentucellia
• Species: Parentucellia viscosa (L.) Caruel

Common names: Yellow bartsia, yellow glandweed, sticky‑parentucellia.

Description
Parentucellia viscosa is an erect annual herb that attains a height of 50–70 cm. The plant bears a stiff, slender stem covered with short, glandular hairs that give it a sticky texture. Leaves are lance‑shaped to oval, toothed along the margins, and also bear glandular hairs. The inflorescence is a raceme of tubular, yellow flowers positioned terminally on the stem. Each flower possesses a calyx of sepals that extends most of the corolla length; the corolla can exceed 2 cm and is lobed and bilabiate.

Ecology
The species is a root hemiparasite, forming haustorial connections with the roots of host plants, particularly members of the Poaceae (grasses) and Fabaceae (legumes). Parasitism can reduce the vigor of host species, influencing plant community composition where the parasite is abundant.

Native and introduced range

• Native distribution: Europe, with a Mediterranean‑Atlantic affinity.
• Introduced range: The species has been recorded on several other continents, including Australia, North America (particularly coastal regions of the western United States), and parts of Asia (e.g., Japan). In introduced locales it often occupies disturbed habitats such as wetlands, pasturelands, and coastal dunes, where it can become invasive.

Habitat
In both native and introduced ranges, P. viscosa is commonly found in moist, open habitats—wetland prairies, floodplain vegetation, pastures, and sandy coastal sites. It prefers well‑drained soils but can tolerate a range of substrate conditions.

Reproductive biology
Flowering occurs in the summer months, after which the plant produces small capsular fruits that release numerous minute seeds adapted for wind dispersal. As an annual, the species relies on seed banks for persistence across years.

Conservation status
The species is not listed as threatened in its native range. In several introduced regions it is considered a nuisance or invasive species, and management programs aim to control its spread, especially in ecologically sensitive wetlands and native grassland habitats.

References

1. Wikipedia contributors. “Parentucellia viscosa.” Wikipedia, The Free Encyclopedia. Accessed 22 April 2026. https://en.wikipedia.org/wiki/Parentucellia_viscosa.
2. Plants of the World Online, Kew Science. “Parentucellia viscosa (L.) Caruel.” https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:806705-1.
3. USDA NRCS PLANTS Database. “Parentucellia viscosa.” https://plants.usda.gov/home/plantProfile?symbol=PAVI3.
4. Pate, J. S.; Bell, T. L. (2000). “Host Associations of the Introduced Annual Root Hemiparasite Parentucellia viscosa in Agricultural and Bushland Settings in Western Australia.” Annals of Botany 85(2): 203–213.
5. Suetsugu, K.; Takeuchi, Y.; Futai, K.; Kato, M. (September 2012). “Host selectivity, haustorial anatomy and impact of the invasive parasite Parentucellia viscosa on floodplain vegetative communities in Japan.” Botanical Journal of the Linnean Society 170(1): 69–78.

This entry reflects the current scientific consensus and available reliable sources as of April 2026.