Carnegiea gigantea, Giant Saguaro

Southwest Desert Flora

Home to the plants of the Sonoran, Chihuahuan and Mojave Deserts

Cirsium ochrocentrum, Yellowspine Thistle

Trixis californica, American Threefold

American Threefold has bright yellow tubular disk flowers. The flowers have asymmetrical “lips” with one larger than the other giving rise to the look of a ray flower as shown here. Trixis californica American Threefold bright yellow tubular flowers are a magnet for insects such as this native bee enjoying a little nectar. Trixis californica American Threefold floral “lips” turns whitish with age as shown in the photo. Trixis californica American Threefold is a shrub or subshrub; the plants are leafy, and the herbage is from a woody base; plants have numerous branches with slender, weak but stiff slender stems. Trixis californica American Threefold leaves are dark green, up to 2 inches (5 cm) long; as shown here the blades are mostly lance-shaped with a few, fine teeth or almost smooth along the edges. The leaves are densely glandular mostly under the leaf.  Trixis californica American Threefold grows up to 3 feet (91 cm) tall and 1 to 3 feet (30-91 cm) wide or more. Plants bloom from January or February to June or July and again, in August and October or throughout the year with adequate monsoon rainfall. Trixis californica

Scientific Name: Trixis californica
Common Name: American Threefold

Also Called: American Trixis, California Trixis, Trixis (Spanish: Arnica, Hierba del Aire, Plumilla, Santa Lucía, Hierba del Pasmo, Ruina)

Family: Asteraceae, Sunflower Family

Synonyms: (Trixis californica var. californica)

Status: Native

Duration: Perennial

Size: To 3 feet (91 cm) tall and 1 to 3 feet (30-91 cm) wide or more.

Growth Form: Shrub or subshrub; plants leafy, often wider than tall; herbage from a woody base; plants upright (erect); numerous branches; stems stiff, slender, weak; herbage glandular, covered with short, soft, erect hairs (pubescent).

Leaves: Dark green; leaves up to 2 inches (5 cm) long, blades mostly lanceolate with few, fine teeth or almost smooth along the edges (margins), edges often curled or rolled under (revolute); leaves stiff or rigid, pointed at both ends, mostly stemless (sessile); leaves alternate to whorled; densely glandular mostly below.

Flower Color: Yellow, bright yellow; small heads buried in leafy bracts; 10 to 15 flower heads; multiple flower heads on branch tips (terminal), single (solitary) heads or clustered; tubular disk florets only; the florets have two asymmetrical lips, one larger than the other and they are called “bilabiate”, the floral lips turn whitish with maturity; fruit is a cypsela with a pappus of straw-colored bristles.

Flowering Season: January or February to June or July; again, in August and October or throughout the year with adequate monsoon rainfall.

Elevation: Up to 5,000 feet (1,524 m).

Habitat Preferences: Lower and upper deserts, lower to middle elevations; southern exposures, dry sunny areas, ridges, rocky hillsides and slopes, desert washes.

Recorded Range: The southwestern United States in AZ, CA, NM and TX; native also throughout most of Baja California and northern Mexico in Chihuahua, Coahuila, Durango, Nuevo León, Sinaloa, Sonora, Tamaulipas, and Zacatecas. Largest geographic range in AZ, large ranges in southeast CA, southwest NM and extreme west TX.

North America & US County Distribution Map for Trixis californica.

North America species range map for American Threefold, Trixis californica:

Click image for full size map

U.S. Weed Information: Unknown
Invasive/Noxious Weed Information: Unknown
Wetland Indicator: Unknown
Threatened/Endangered Information: Unknown

Genus Information: In North America there are 2 species and 3 accepted taxa overall for Trixis. Worldwide, The Plant List includes 42 accepted species names and a further 66 scientific names of infraspecific rank for Trixis.

The genus Trixis was published in 1756 by Patrick Browne, (1720-1790). The taxon Trixis californica was published in 1863 in the Proceedings of the California Academy of Sciences, by Albert Kellogg, Albert (1813-1887).

In the Southwestern United States: Arizona, California, Nevada, New Mexico and Utah each have 1 species of Trixis, Texas has 2 species. Data approximate, subject to revision.

There is 1 variety in Trixis californica in the United States:
Trixis californica var. californica

Comments: Trixis is a common plant in both lower and upper desert habitats, often growing in and among other taller shrubs and trees. It is well represented throughout its range.

Importance to Wildlife, Birds and Livestock
American Threefold, Trixis californica has showy bright yellow daisy-type flowers, the flowers, their seeds and plants may be visited by hummingbirds and/or small mammals including rodents and granivorous birds in search of food, nectar and protection through cover.

Beneficial Value to Butterflies, Honey Bees and Insects
American Threefold, Trixis californica has showy bright yellow daisy-type flowers, the flowers and their plants may be visited or used by butterflies, moths, flies, honeybees, native bees and other insects in search of nectar, food or shelter and protection.

The genus “Trixis” (Trix'is:) is from the Greek trixos, "three-fold," referring to the three-cleft outer corolla lip.

The genus Trixis was published in 1756 by Patrick Browne, (1720-1790) The taxon Trixis californica was published in 1863 in the Proceedings of the California Academy of Sciences, by Albert Kellogg, Albert (1813-1887).

The species epithet californica (califor'nica:) of or from California.

According to Arizona Sonora Desert Museum; “The Seri regard this plant as a panacea, claiming that there is nothing that this medicinal herb is not good for. Among its wide range of uses, trixis is smoked like tobacco and administered as an aid to childbirth.”

Date Profile Completed: 06/08/2012; updated 12/10/2020
Arizona Flora, Kearney, Thomas H., Peebles, Robert H., 1960, University of California Press, Berkley and Los Angeles
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Native Plant Information Network, NPIN (2013). Published on the Internet; accessed 12/10/2020. Lady Bird Johnson Wildflower Center at The University of Texas, Austin, TX.
Wiggins 1964, FNA 2006, Benson and Darrow 1981, Kearney and Peebles 1969 Editors: S.Buckley 2010, F.S.Coburn 2015; from SEINet Field Guide, on-line; accessed 12/10/2020.
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Wikipedia contributors, 'Trixis californica', Wikipedia, The Free Encyclopedia, 7 December 2020, 20:50 UTC, [accessed 9 December 2020]
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Felger, Richard Stephen (2016). People of the desert and sea: ethnobotany of the Seri Indians. Moser, Mary Beck. (Century Collection ed.). Tucson, Arizona. ISBN 978-0-8165-3475-3. OCLC 961922305.
2020 Arizona-Sonora Desert Museum; 2021 N. Kinney Rd., Tucson AZ 85743 U.S.A. 520.883.2702 ·; - accessed 12/10/2020
Aggie-Horticulture, Ornamental Plants American Trixis; Trixis californica; (accessed: 12/09/2020)
Seiler, John, Peterson, John, North American species range map courtesy of Virginia Tech, Dept. of Forest Resources & Environmental Conservation
SEINet synonyms, scientific names, geographic locations, general information.
Etymology:Michael L. Charters California Plant Names: Latin and Greek Meanings and Derivations; A Dictionary of Botanical and Biographical Etymology - (accessed 12/10/2020)
IPNI (2020). International Plant Names Index. Published on the Internet, The Royal Botanic Gardens, Kew, Harvard University Herbaria & Libraries and Australian National Botanic Gardens. [Retrieved 10 December 2020].