Carnegiea gigantea, Giant Saguaro

Southwest Desert Flora

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

Cirsium ochrocentrum, Yellowspine Thistle

Machaeranthera tagetina, Mesa Tansyaster

Mesa Tansyaster has bright purple with yellow centers; very showy daisy-like flower; heads with both ray and disk florets. Machaeranthera tagetina Mesa Tansyaster blooms from March to November following monsoon rainfall. Machaeranthera tagetina Mesa Tansyaster has large green linear bracts that surround the flowering heads as shown in the photo. Machaeranthera tagetina Mesa Tansyaster has green or grayish-green leaves that are arranged alternately along the stems. Note that the leaves are segmented (pinnatifid) and spine tipped. Machaeranthera tagetina Mesa Tansyaster is a native annual that grows from a taproot. Plants prefer elevations from 1,500 to 5,500 feet (457-1,676 m). Machaeranthera tagetina Mesa Tansyaster grows in the upper and lower Sonoran Desert and transition habitats and prefers slopes, grassy areas, mesas, streambeds and roadsides. Machaeranthera tagetina

Scientific Name: Machaeranthera tagetina
Common Name: Mesa Tansyaster

Also Called: Mesa Tansy-aster (Spanish: Flor de Capita)

Family: Asteraceae, Sunflower Family

Synonyms: (Aster tagetinus, Machaeranthera humilis)

Status: Native

Duration: Annual with a taproot.

Size: Up to 20 inches (51 cm) tall, more or less.

Growth Form: Forb/herb; stems green, slender, branched; stems covered with minute soft erect hairs, some hairs, gland-tipped; attractive daisy-like flower.

Leaves: Green or grayish-green leaves; leaves arranged alternately along stems; pinnatifid and spine-tipped.

Flower Color: Bright purple and yellow showy flower heads; heads with both ray and disk florets; the bracts surrounding the heads are linear; fruit is a cypsela with pappus.

Flowering Season: March to November, summer blooms follow monsoon rainfall; blooms earlier in California; July to October or December

Elevation: 1,500 to 5,500 feet (457-1,676 m)

Habitat Preferences: Lower and upper Sonoran Desert and transition habitats, pinion-juniper, pine-oak woodlands and evergreen-oak communities and Creosote (Larrea) communities; slopes, grassy areas, mesas, streambeds and roadsides.

Recorded Range: Rare in the United States, found only in Arizona and New Mexico and also Baja California and Mexico in Chihuahua and Sonora. It is found throughout much of Arizona, heavy in central and south portions and in New Mexico where it is limited to the southern and southwest corner of the state.

North America & US County Distribution Map for Machaeranthera tagetina.

North America species range map for Mesa Tansyaster, Machaeranthera tagetina:

North America species range map for Mesa Tansyaster, Machaeranthera tagetina: Click image for full size map.
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 18 species and 18 accepted taxa overall for genus. Worldwide, The Plant List includes 27 accepted species names and a further 18 scientific names of infraspecific rank for the genus.

The genus Machaeranthera was published by Christian Gottfried Daniel Nees von Esenbeck in 1832.

In the Southwestern United States: Arizona has 13 species of genus, California has 8 species, Nevada has 8 species, New Mexico has 14 species, Texas has 8 species, Utah has 8 species. Data approximate and subject to revision.

Comments: Mesa Tansyaster is a smaller species in the genus with a daisy-like flower. It is a rare species in the United States as it is found mostly in Arizona; smaller geographic ranges, with smaller populations are found in New Mexico. Although rare, this Sonoran Desert species is common in its preferred habitat where it is found.

Species of the genus Machaeranthera, are found primarily in the western parts of North America. They are commonly known as tansyasters. The word Machaeranthera is Greek for sword-like anthers and the anthers are actually sword-shaped and sharp-pointed. The pinnately shaped leaves helps seperate this genus from the similar Dieteria whose leaves are simple.

In Southwest Desert Flora also see Alkali Marsh Aster, Almutaster pauciflorus, Tansyleaf Tansyaster, Machaeranthera tanacetifolia, Hoary Tansyaster, Dieteria canescens and Mojave Woodyaster, Xylorhiza tortifolia.

Importance to Wildlife, Birds and Livestock
Machaeranthera tagetina, Mesa Tansyaster, daisy-like flowers, seeds and plants may be visited by hummingbirds and/or small mammals including rodents in search of food.

Beneficial Value to Butterflies, Bees and Insects
Machaeranthera tagetina, Mesa Tansyaster, daisy-like brightly colored flowers and plants may be visited by butterflies, moths and other insects in search of food and nectar.

The genus “Machaeranthera” (Machaeran'thera:) is Greek for sword-like anthers.

The genus Machaeranthera was published by Christian Gottfried Daniel Nees von Esenbeck in 1832.

The species epithet tagetina (tageti'na:) is possibly named from genus Tagetes, which is named after the Etruscan god Tages who supposedly emerged from the earth as it was being ploughed and was imbued with the power of divination.

Date Profile Completed: 7/10/2012; updated 09/01/2020
Arizona Flora, Kearney, Thomas H., Peebles, Robert H., 1960, University of California Press, Berkley and Los Angeles, as Aster tagetinus.
U.S. Dept. of Agriculture, Natural Resources Conservation Service on-line database and USGS ITIS search - accessed 09/01/2020.
The Plant List (2013). Version 1.1. Published on the Internet; - accessed 09/01/2020.
David R. Morgan, Ronald L. Hartman, Flora of North America; Asteraceae, Machaeranthera, 2. Machaeranthera tagetina Greene, Pittonia. 4: 71. 1899.; Flora of North America North of Mexico. 16+ vols. New York and Oxford.
FNA 2006, Wiggins 1964, Kearney and Peebles 1969; Editor: S.Buckley, 2010; from SEINet Field Guide, on-line; - accessed 09/01/2020.
T. Beth Kinsey, Southeastern Arizona Wildflowers and Plants; Machaeranthera tagetina – Mesa Tansyaster - accessed on 09/01/2020.
Seiler, John, Peterson, John, North American species range map courtesy of Virginia Tech, Dept. of Forest Resources & Environmental Conservation
Wikipedia contributors, 'Machaeranthera', Wikipedia, The Free Encyclopedia, 27 May 2020, 17:07 UTC, [accessed 1 September 2020]
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 09/01/2020.