Troximon grandiflorum Nutt.

Scientific Name: Troximon grandiflorum Nutt.

Plant Guide

Alternate Names

Common Alternate Names: Mountain dandelion, goat chicory Scientific Alternate Names: A, grandiflora (Nutt,) Greene var, Use soil moisture sensors to measure the soil moisture of Troximon grandiflorum Nutt.., leptophylla G,I, Baird; A, laciniata (Nutt,) Greene; A, plebeja (Greene) Greene; Stylopappus grandiflorus Nutt,; S, laciniatus var, longiflorus Nutt,; Troximon grandiflorum Nutt,

Uses

Sage-grouse (Centrocercus urophasianus) hens and chicks eat the leaves of Agoseris species (Barnett and Crawford 1994; Klebenow and Gray 1968). Bigflower agoseris has been investigated for potential use in rangeland restoration and rehabilitation seedings. Large scale seed production including seed harvesting however is problematic.

Status

Please consult the PLANTS Web site and your State Department of Natural Resources for this plant’s current status (e.g., threatened or endangered species, state noxious status, and wetland indicator values).

Description

General: Sunflower family (Asteraceae). Bigflower agoseris is a short lived perennial forb from a simple or branched taproot. The stems and leaves contain a white milky juice. The leaves are all basal with the flower heads solitary on a naked scape. Leaves are 8 to 25 cm (3 to 10 in) long and 1 to 3 cm (0.4 to 1.2 in) wide, oblanceolate pinnatifid to nearly entire. The flowering stems are 15 to 45 cm (6 to 18 in) tall (Welsh et al. 2003). The floral heads are made of numerous yellow ray flowers (similar to a dandelion). Flowering occurs in spring. The fruit is an achene with a 4 to 7 mm (0.16 to 0.28 in) long body gradually tapering into a long beak which averages more than twice as long as the body. There are approximately 274,000 seeds/lb (USDA NRCS 2012). Distribution: Bigflower agoseris occurs in western North America from British Columbia south to California and east to Montana and Utah. For current distribution, please consult the Plant Profile page for this species on the PLANTS Web site. Habitat: Bigflower agoseris is found in small numbers in grassland, sagebrush and mountain brush communities below 2,000 m (6,500 ft) (Hickman 1993; Welsh et al. 2003).

Adaptation

This species is adapted to a broad range of soil types. It typically occurs in soils with a pH of 5.8-7.3 in areas receiving 300 to 500 mm (12 to 20 in) mean annual precipitation (USDA NRCS 2012). Big flower agoseris prefers open sun.

Establishment

Bigflower agoseris can be seeded in spring or fall (Skinner, 2004). It should be planted into a firm, weed-free seed bed at a depth of 1/8 to 1/4 inches. The recommended full stand seeding rate is 4 lbs pure live seed (PLS) per acre (Ogle et al. 2011). Seeding rates should be adjusted accordingly when used as part of a mixture.

Management

Bigflower agoseris should be used as a minor component of seed mixtures. Management strategies should be based on the key species in the established plant community. Grazing should be deferred on seeded lands for at least two growing seasons to allow for full stand establishment (Ogle et al. 2011).

Pests and Potential Problems

Rodents such as gophers and voles will attack the roots of bigflower agoseris in seed production fields (Skinner 2004).

Environmental Concerns

Concerns

Concerns

Bigflower agoseris is native to western North America and poses no known environmental concerns.

Seeds and Plant Production

Plant Production

Plant Production

Seed is collected in midsummer from early June through late July. The seed is dark brown to black when mature and the pappus is white and expanded. The pappus can be removed with a hammer mill or brush machine, but pappus removal is not necessary for greenhouse propagation (Skinner 2004; Young 2001). Bigflower agoseris has no pre-chill requirement. Seed germinates approximately 14 days after sowing (Young 2001). Container grown plants are ready for out-planting after approximately 60 days (Skinner 2004). Cultivars, Improved, and Selected Materials (and area of origin) Seed of bigflower agoseris is available in limited quantities on the commercial market. Larger quantities of seed may be grown on a contract basis.

References

Barnett, J.K. and J.A. Crawford. 1994. Pre-laying nutrition of sage grouse hens in Oregon. Journal of Range Management. 47: 114-118. Hickman, J.C., ed. 1993. The Jepson manual: higher plants of California. Berkeley: University of California Press. 1400 p. Klebenow, D.A and G.M. Gray. 1968. Food habits of juvenile sage grouse. Journal of Range Management. 12: 80-83. Ogle, D., St. John, L., Stannard, M., and L. Holzworth. 2011. Technical Note 24: Conservation plant species for the Intermountain West. USDA-NRCS, Boise, ID-Salt Lake City, UT-Spokane, WA. ID-TN 24. 57p. Skinner, David M. 2004. Propagation protocol for production of container Agoseris grandiflora (Nutt.) Greene plants; USDA NRCS - Pullman Plant Materials Center, Pullman, Washington. In: Native Plant Network. URL: http://www.nativeplantnetwork.org (accessed 9 November 2012). Moscow (ID): University of Idaho, College of Natural Resources, Forest Research Nursery. [USDA NRCS] USDA Natural Resources

Plant Traits

Growth Requirements

Morphology/Physiology

Reproduction

Suitability/Use