American thorow wax
Bupleurum americanum

Alaska Wildflowers | Yellow

Side view of Bupleurum americanum, commonly known as American thorow wax with numerous umbelleles of small yellow flowers and grasslike leaves

American thorow wax
Bupleurum americanum

Common Names

buplèvre d’Amérique
American throw wax
American thoroughwax
American thorough-wax

Synonyms

Bupleurum purpureum
Bupleurum sibiricum
Bupleurum triradiatum ssp. arcticum

Subspecies

none

Genus: Bupleurum
Family: Apiaceae
Order: Apiales
taxonomic hierarchy

Duration – Growth Habit

Perennial – Forb/herb

Identification and Information

Bupleurum americanum, commonly known as American thorow wax, is a 10-50 cm tall yellow-flowering perennial herb that grows from a many-headed, branching caudex. Stems are typically simple but can be branched and grow erect to ascending. Its leaves are distinctive with parallel veins, grasslike in appearance, and range from 2-25 cm in length. Basal leaves tend to be linear-lanceolate, while those on the stem are narrow oblong-lanceolate.



The inflorescence is composed of compound umbels of 2-9 rays (rarely more than 10) with an involucre of 2-6 leafy bracts below the umbel. Smaller bracts are below the umbellules (or umbellets – secondary umbels). The umbellules are densely flowered, containing 10-20 small, compact flowers arranged in a hemisphere at the tip of the stems. The petals are yellow with inrolled margins and about 1 mm long or less. The flowers produce two oblong to narrowly elliptic fruits (capsules), 5 mm in length, with short ribs.

Flowering July-August


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Uses

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

No traditional, medicinal, or culinary uses were found.


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Distribution and Habitat

Bupleurum americanum is the only species of the genus in North America, where it is found in Alaska, Idaho, Montana, Wyoming, Alberta, the Yukon, and the Northwest Territories. It is listed as critically imperiled in Oregon, South Dakota, and Colorado. Its range extends into eastern Siberia.

The plant is found in dry and rocky sites in meadows, hills, or mountains.

Classification

RankScientific Name (Common Name)
KingdomPlantae (plantes, Planta, Vegetal, plants)
   SubkingdomViridiplantae (green plants)
      InfrakingdomStreptophyta (land plants)
         SuperdivisionEmbryophyta 
            DivisionTracheophyta (vascular plants, tracheophytes)
               SubdivisionSpermatophytina (spermatophytes, seed plants, phanérogames)
                  ClassMagnoliopsida 
                     SuperorderAsteranae 
                        OrderApiales 
                           FamilyApiaceae 
                              GenusBupleurum L.
                                 SpeciesBupleurum americanum J.M. Coult. & Rose (American thorow wax)

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References and Further Reading

Guidebooks/Printed Floras

Hultén, E. (1968). Flora of Alaska and Neighboring Territories: A Manual of the Vascular Plants (1st ed.) (pg. 916). Stanford University Press.

Classification and Taxonomy

ITIS (2024). Bupleurum americanum. Retrieved March 31, 2024, from https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=29605

Database of Vascular Plants of Canada (VASCAN). (2024). Bupleurum americanum. Retrieved March 31, 2024, from https://data.canadensys.net/vascan/name/Bupleurum%20americanum

USDA NRCS PLANTS Database. (2024). Bupleurum americanum. Retrieved March 31, 2024, from https://plants.usda.gov/home/plantProfile?symbol=BUAM2

Uses

Map and Distribution

GBIF (2024). Bupleurum americanum. Retrieved March 31, 2024, from https://www.gbif.org/species/3034555

Plants of the World Online (POWO). (2024). Bupleurum americanum. Retrieved March 31, 2024, from https://powo.science.kew.org/taxon/urn:lsid:ipni.org:names:38355-2

NatureServe Explorer. (2024). Bupleurum americanum. Retrieved March 31, 2024, from https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.131994/Bupleurum_americanum

Description and Information

University of Alaska Fairbanks. (2024). Bupleurum americanum. Retrieved March 31, 2024, from https://ecologicalatlas.uaf.edu/index.php/browse-plant-species/atlas-page/?nps_id=276

The American Southwest. (2024). Bupleurum americanum. Retrieved March 31, 2024, from https://www.americansouthwest.net/plants/wildflowers/bupleurum-americanum.html

Montana Field Guide. (2024). Bupleurum americanum. Retrieved March 31, 2024, from https://fieldguide.mt.gov/speciesDetail.aspx?elcode=PDAPI0F010

Oregon Flora. (2024). Bupleurum americanum. Retrieved March 31, 2024, from https://oregonflora.org/taxa/index.php?taxon=3443

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