Kingdom: Plantae

Phylum: Magnoliophyta -- flowering plants

Class: Magnoliopsida -- dicots

Family: Asteraceae

Common Name: large-flowered agoseris, bigflower agoseris

Species Code: AGGR

Origin: Native to open areas such as meadows and prairies in Washington, north and central Idaho, south to California.

Rare: no

Form: Forb, scapose perennial, pilose, becoming glabrate later, 20-60 cm tall, with milky sap and a brown taproot.

Duration: perennial

Longevity: short-lived

Habitat Type: prairie, shrub thickets

Wetland Indicator Status: Not on list.

Leaves: leaves 10-30 cm long, oblanceolate to spatulate or linear; margins entire, dentate or pinnately lobed.

Mature height: 20-60 cm

Flowers: yellow, all ligulate and perfect, opening in the morning and closing up before noon.

Flower color: yellow

Bloom: June/Aug

Bloom starts on: June

Bloom ends on: August

Fruit: achene, 5-6 mm long, ribbed, tapering to a long beak, pappus minutely barbellate.

Characteristics:
Reproduces sexually by seed.
273,665 seeds/lb (USDA NRCS Pullman PMC 2005).
2n=18.
Apomixis may occur in the genus.
Flowering and fruiting may continue into October with suitable site and weather conditions.
Polyploidy occurs in some species of Agoseris, but apparently not in A. grandiflora.
Seeds are windborne.
Taprooted.

Sun requirement: full

Soil moisture: xeric to mesic

Precipitation: 12-20 inches (USDA NRCS PLANTS Database 2007).

Sowing time: fall or early spring

Transplant time: spring

Stratification: none

Seed yield: medium

Seed harvest: difficult, must be hand harvested daily.

Seed first harvest: same season

Seed cleaning: removing the pappus and beak is somewhat difficult, but the seed is easily cleaned once they have been removed.

Planting duration: short

Seed insect problem: none noted

Seed shatter: high

Seed size: large

Seed harvest date: begins in early July.

Seed comments: wind-borne seed, indeterminate flowering and seed ripening

Propagation:
2 protocols in the Native Plant Network
Golden Gate National Park, California
Plant Materials Center, Pullman Washington

Other Propagation Information:
Germinate at 15 or 20^oC in the dark (Chirco & Turner 1986).
Germination is highest in the dark at 15 or 20^oC (Maguire & Overland 1959).
Reproduces sexually by seed.

Notes:
Rodents will eat the taproot and kill the plant.
A. grandiflora is short-lived but perpetuates itself by abundant seed production. Seeds are windborne and establish readily in gaps in the vegetative cover.

References:
Chirco, Ellen and Terry Turner. 1986. Species Without AOSA Testing Procedures. The Newsletter of the Association of Official Seed Analysts. Vol 60(2):2-66.

Maguire, James D. and Alvin Overland. 1959. Laboratory Germination of Seeds of Weedy and Native Plants. Washington State Agricultural Experiment Station Circular 349, Pullman, WA. 15 p.

Price, H. James and Konrad Bachman. 1975. DNA Content and Evolution in the Microseridinae. American Journal of Botany 62:262-267.

USDA, NRCS, Pullman Plant Materials Center. 2005. Seed Weights of Some Palouse Native Species. Pullman Plant Materials Center, Pullman, Washington. Online at http://www.wsu.edu/~pmc_nrcs/Docs/Seed_Weights_Palouse_Native_Species.pdf

USDA, NRCS. 2009. The PLANTS Database (http://plants.usda.gov, 13 July 2009). National Plant Data Center, Baton Rouge, LA 70874-4490 USA.

Links:
Plant Profile from the USDA PLANTS Database
Species description from Flora of North America
Species information from the University of Washington Herbarium