Steve Redman (MORA), no rights reserved (CC0) · Wikimedia Commons

Agoseris, Genus, spp., Multiple species,

Genus
Multiple species

mountain dandelions

Asteraceae

Western North America, with a few species in South America

Attracts Pollinators Attracts Butterflies Drought Tolerant

SunFull Sun

WaterLow · drought-tolerant

HardinessZones 3–8

Overview

Agoseris is a genus of about 10 to 12 species of annual and perennial herbs in the daisy family Asteraceae, native mostly to western North America with a few species reaching South America. Plants form a basal rosette of narrow, lance-shaped to lobed leaves, 2-14 in (5-35 cm) long, rising from a taproot, and all parts release a milky white latex when cut. Each leafless stalk, 2-24 in (5-60 cm) tall, bears a single dandelion-like head made up entirely of strap-shaped ray florets, usually in yellow but orange to burnt-red in A. aurantiaca and sometimes drying to pink or purple. Flowering occurs from late spring through summer, the timing shifting with elevation. The seed heads form a fluffy parachute cluster much like a true dandelion, dispersing on the wind. The genus grows in meadows, prairies, open woodland, and alpine slopes, often in seasonally dry mountain sites. Many species are perennial, regrowing from the taproot each year, while a few are annuals. Cold tolerance reaches roughly USDA zones 3 to 8 in the perennial species.

Native Range

Agoseris is native primarily to western North America, from Alaska and Canada south through the western United States to Mexico, with a few species in temperate South America. Plants occur in meadows, grassland, open forest, and alpine and subalpine slopes.

Suggested Uses

Agoseris species are grown in native-plant, meadow, and rock gardens and in prairie and alpine restorations. The yellow flowers and fluffy seed heads support pollinators and seed-eating birds. The genus suits naturalistic plantings rather than formal borders.

How to Identify

Identify Agoseris by a basal rosette of narrow leaves and single yellow dandelion-like heads, each on its own leafless stalk, with milky sap throughout. The flower heads are made only of ray florets, and the fluffy seed heads resemble a dandelion. Narrow, often lobed leaves and mountain or meadow habitats separate it from the weedy true dandelions.

Appearance

Size & Dimensions

Height2" - 2'

Width/Spread4" - 1'

Colors

Flower Colors

Foliage Colors

Fall Foliage Colors

Bloom Information

Bloom Period

~6 weeks

Flowers: May–August

Spring Summer

Flowering runs from late spring through summer, beginning earlier at low elevations and later in alpine sites. Each stalk carries one head that opens for a few days. A plant produces a succession of heads over several weeks.

Detailed Descriptions

Foliage Description

green

Growing Conditions

Sun Requirements

SunFull Sun

Requires 6-10 hours of direct sunlight daily

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range6.0 - 7.5 (Neutral to alkaline)

3579

Soil Types

loam sand rocky

Drainagewell drained

Water & Climate

Water Needs

Low

Frost Tolerance

hardy

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Agoseris species grow in full sun in average to dry, well-drained soil with a pH near 6.0 to 7.5, including gravelly and rocky ground. They tolerate drought and the lean soils of their native meadows and slopes. Perennial species are cold-hardy through USDA zones 3 to 8 and regrow from a deep taproot. Because of that taproot, established plants resist transplanting and are raised from seed. The genus needs little water or feeding once settled. Plants self-sow on open ground where the wind-borne seed lands.

Pruning

No routine pruning is needed for this rosette-forming genus. Spent flower stalks can be removed to limit self-seeding or left for seed-eating birds. Foliage dies back in winter and is cleared in spring.