Roundleaf sundew – Drosera rotundifolia

Alaska Wildflowers | Other Colors

Roundleaf sundew

Drosera rotundifolia

Common Names

droséra à feuilles rondes [French]
roundleaf sundew
round-leaf sundew

Synonyms

Drosera rotundifolia var. comosa
Drosera rotundifolia var. gracilis
Drosera rotundifolia var. rotundifolia

Subspecies

None, but hybrids occur with D. anglica

Genus: Drosera
Family: Droseraceae (Sundews)
Order: Caryophyllales
full classification

Duration – Growth Habit

Perennial – Forb/herb

Identification and Information

Drosera rotundifolia, commonly known as the round-leaved sundew, is an insect-eating perennial herb notable for its unique carnivorous traits. This plant develops winter hibernaculae: compact, bud-like structures that shield its growing points during cold weather. The plant forms rosettes ranging from 2 to 15 cm in diameter and possesses a non-bulbous-cormose stem base. Its leaves, primarily basal, range from erect to prostrate and are suborbicular (almost circular), measuring about 6-12 mm in length and width. Each leaf blade, significantly shorter than its 1.5-5 cm petiole, is glandular-pilose. The upper surface of the leaves features reddish hairs that are gland-tipped, secreting a sticky fluid to trap insects. Short hairs on the leaf surface secrete digestive enzymes, breaking down trapped insects into soluble nutrients absorbed by the leaf cells. The plant lacks stipules, and stem leaves are notably absent.

The inflorescence is a raceme-like terminal cyme consisting of 2 to 15, sometimes up to 25, flowers. These flowers open in full sun in a coiled cluster on one side of the 5-35 cm tall, glabrous scape. The flowers themselves are 4-7 mm in diameter, with white or pink petals that are spatulate and about 5-6 mm long. It has 5 stamens and 3 styles. The sepals are oblong, connate at the base, and measure 4-5 mm. Fruits are capsules, many-seeded, with the seeds being light brown, fusiform (spindle-like), and finely striated, measuring 1-1.5 mm.

Uses

For information only (typically historical) – I take no responsibility for adverse effects from the use of any plant.

Drosera rotundifolia has a few traditional uses and has gained recognition for potential health benefits. The Kwakiutl tribe of British Columbia historically used the plant as a dermatological aid for treating corns, warts, and bunions, and as a unique ‘love medicine’ to create love charms. This traditional knowledge is documented in Nancy Chapman Turner and Marcus A. M. Bell’s ethnobotanical study of the Southern Kwakiutl Indians.

Modern research has highlighted the medicinal potential of Drosera rotundifolia, indicating that extracts from the plants can have anti-inflammatory and anti-spasmadic properties. These benefits are attributed to the presence of flavonoids such as hyperoside, quercetin, and isoquercetin. Ellagic acid in the extracts also demonstrates antiangiogenic effects (inhibiting the ability to form new blood vessels which can be beneficial in certain cancer treatments and certain eye diseases). These findings suggest potential applications in treating conditions involving inflammation and spasms.

For more detailed scientific information, the research is accessible via the National Institutes of Health and other academic publications.

Distribution and Habitat

The roundleaf sundew thrives in cooler climates and is found widely across Alaska, Canada, northern and coastal regions of the United States, much of Europe, Siberia, China, Japan, and the Korean Peninsula. There are rare occurrences of this species in a peat bog in the Philippines, as well as in isolated locations in Indonesia, New Zealand, and potentially other parts of the Pacific Islands and Southeast Asia.

This species typically inhabits sphagnum swamps, bogs, fens, beaver ponds, and other swampy areas, as well as peaty gravel, sandy soils, along shorelines, and at sphagnous streamheads. It’s typically found from sea level up to 3000 meters.

Classification

References and Further Reading

Guidebook

Hultén, E. (1968). Flora of Alaska and Neighboring Territories (Amazon). Stanford University Press. p. 559.

Classification and Taxonomy

ITIS (n.d.). Drosera rotundifolia. Integrated Taxonomic Information System. Retrieved November 30, 2023, from https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=22017#null

USDA (n.d.). Drosera rotundifolia. United States Department of Agriculture Natural Resources Conservation Service. Retrieved November 30, 2023, from https://plants.usda.gov/home/plantProfile?symbol=DRRO

Uses

Native American Ethnobotany Database (n.d.). Drosera rotundifolia. Retrieved November 30, 2023, from http://naeb.brit.org/uses/species/1332/

Hake, A., Begrow, F., Spiegler, V., Symma, N., Hensel, A., & Düfer, M. (2022). Effects of Extracts and Flavonoids from Drosera rotundifolia L. on Ciliary Beat Frequency and Murine Airway Smooth Muscle. NIH National Library of Medicine. Retrieved November 30, 2023, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9572773/

Map and Distribution

Hake, A., Begrow, F., Spiegler, V., Symma, N., Hensel, A., & Düfer, M. (2022). Effects of Extracts and Flavonoids from Drosera rotundifolia L. on Ciliary Beat Frequency and Murine Airway Smooth Muscle. NIH National Library of Medicine. Retrieved November 30, 2023, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9572773/

NatureServe (n.d.). Drosera rotundifolia. NatureServe Explorer. Retrieved November 30, 2023, from https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.158710/Drosera_rotundifolia

Amoroso, V. B., & Aspiras, R. A. (2017). Distribution of the seven species of Drosera in the Philippines. In ResearchGate. Retrieved November 30, 2023, from https://www.researchgate.net/figure/Distribution-of-the-seven-species-of-Drosera-in-the-Philippines_fig2_303734731

Rice, B. A. (2021). The thread-leaved sundews (Drosera section Lasiocephala) of the New World. Carnivorous Plant Newsletter, 50(1), 7-15. Retrieved November 30, 2023, from https://cpn.carnivorousplants.org/articles/CPNv50n1p7_15.pdf

Description and Information

Flora of North America Editorial Committee (n.d.). Drosera rotundifolia. Flora of North America. Retrieved November 30, 2023, from http://floranorthamerica.org/Drosera_rotundifolia

E-Flora BC (n.d.). Drosera rotundifolia. Electronic Atlas of the Flora of British Columbia. Retrieved November 30, 2023, from https://linnet.geog.ubc.ca/Atlas/Atlas.aspx?sciname=Drosera%20rotundifolia&redblue=Both&lifeform=7