Carnegiea gigantea, Giant Saguaro

Southwest Desert Flora

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

Cirsium ochrocentrum, Yellowspine Thistle

Almutaster pauciflorus, Alkali Marsh Aster

Alkali Marsh Aster has purple, lavender or whitish medium sized showy flowers with anywhere from 3 to 10 floral heads per plant. These daisy-type flowers are called radiate meaning they have both ray and disk florets included in the head. Almutaster pauciflorus Alkali Marsh Aster flowers somewhat glandular phyllaries (bracts surrounding floral parts) as shown in the photo. Almutaster pauciflorus Alkali Marsh Aster grows from 12 to 47 inches (30-120 cm) tall depending on the locality. Plants bloom from May to September, June to October in California and prefer elevations from 650 to 7,800 feet (200–2400 m), again depending on locality. Almutaster pauciflorus Alkali Marsh Aster grows has large green leaves that generally have smooth margins. Note in the photo that the basal leaves are more linear and the leaves higher up on the stem are narrowly spatulate. Almutaster pauciflorus

Scientific Name: Almutaster pauciflorus
Common Name: Alkali Marsh Aster

Also Called: Alkalai Marsh Aster, Alkali-marsh Aster, Alkalimarsh Aster, Marsh-Aster

Family: Asteraceae, Sunflower Family

Synonyms: (Aster pauciflorus, Aster hydrophilus, Tripolium pauciflorum)

Status: Native

Duration: Perennial

Size: 12 to 47 inches (30-120 cm) depending on locality.

Growth Form: Forb/herb; rhizomes, partially colonial; stems erect to ascending, reddish-green, glabrate, upper stems glandular-pubescent.

Leaves: Green; margins entire but may be ciliate; basal leaves linear, petiolate; cauline leaves sessile, clasping, mostly elongate-linear, narrowly spatulate, usually stipulate-glandular.

Flower Color: Purple, lavender or whitish, flowers showy, 3 to 10 heads, large, inflorescence panicle-like clusters, heads radiate; involucre campanulate, floral heads on branch tips; ray florets 15 to 30, white to pale purple, disk florets 40 to 50, yellow; phyllaries densely stipitate-glandular without other pubescence; fruit fusiform, hairy, finely ribbed, a (cypsela).

Flowering Season: May to September, June to October in California.

Elevation: 650 to 7,800 feet (200–2400 m) depending on locality.

Habitat Preferences: alluvial and alkaline soil, often found with halophytic vegetation, along streams, ditches, desert and dry prairie areas, inland salt marshes (coastal species).

Recorded Range: Almutaster pauciflorus found from northern Canada (Northwest Territories), Alberta, Saskatchewan, Manitoba southward into the United States through North Dakota, South Dakota, Montana, Wyoming southward through the southwestern United Stated and south into northern and central Mexico (as far south as Tlaxcala); in California this species is found in the Mojave Desert in Inyo and Kern Counties.

North America & US County Distribution Map for Almutaster pauciflorus.

U.S. Weed Information: No information available.
Invasive/Noxious Weed Information: No information available.

Wetland Indicator: In North America Almutaster pauciflorus has the following wetland designations: Arid West, FACW; Great Plains, FACW; Western Mountains, Valleys, and Coast, FACW.
FACW = Facultative Wetland, usually occur in wetlands, but may occur in non-wetlands

Threatened/Endangered Information: In North America Almutaster pauciflorus is listed by California Native Plant Society (CNPS) Rare and Endangered Plant Inventory; California Rare Plant Rank: 2B.2 - Rare or Endangered in California, common elsewhere. 2: Fairly endangered in California

Genus Information: In North America, and world-wide, according to The Plant List, there is 1 species and 1 accepted taxa overall for Almutaster. The genus Almutaster was published in 1982 by Askell Love and Doris Benta Maria Love

Comments: Arizona locations: San Bernardino Ranch and valley of the San Pedro River (Cochise County); Santa Cruz River valley and Aqua Caliente (Pima County)

Importance to Wildlife, Birds and Livestock

Special Value to Native Bees, Butterflies and Insects
Daisy type flowers such as Alkali Marsh Aster often attract a myriad of insects.

The genus Almutaster honors American Aster expert Almut Gitter Jones (Mrs. George Neville Jones - 1923-2013), American botanist and plant systematist. The genus Almutaster was published in 1982 by Askell Love and Doris Benta Maria Love.
The species epithet "pauciflorus" means few-flowered.


Date Profile Completed: 01/29/2020
Kearney, Thomas H., Peebles, Robert H., 1960, Arizona Flora, University of California Press, Berkley and Los Angeles, California; as Aster pauciflorus
U.S. Dept. of Agriculture, Natural Resources Conservation Service on-line database and USGS ITIS search - (accessed 01/27/2020)
The Plant List (2013). Version 1.1. Published on the Internet; (accessed 01/27/2020).
Luc Brouillet; Flora of North America North of Mexico |FNA | Family List | FNA Vol. 20 | Asteraceae | Almutaster 1. Almutaster pauciflorus (Nuttall) Á. Love & D. Love, Taxon. 31: 356. 1982.; Marsh alkali aster (accessed 00/00/2000).
John C. Semple 2012, Almutaster pauciflorus, in Jepson Flora Project (eds.) Jepson eFlora, eflora_display.php?tid=12710, accessed on January 27, 2020.
Alkali Marsh Aster — Almutaster pauciflorus. Montana Field Guide. Montana Natural Heritage Program. Retrieved on January 27, 2020,
'Almutaster', Wikipedia, The Free Encyclopedia, 22 August 2019, 13:45 UTC, [accessed 28 January 2020]
California Native Plant Society (CNPS) Rare and Endangered Plant Inventory (accessed January 27, 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 01/28/2020)