Amphiachyris dracunculoides (prairie broomweed)

Amphiachyris spp.

Native to North America

Overview

Amphiachyris spp. is a small genus of two annual herbs in the family Asteraceae, native to the south-central United States. The plants grow a single slender stem 20-100 cm (8-39 in) tall that branches widely in the upper half into a rounded, broom-like crown, giving the common name broomweed. The narrow, alternate leaves are 1-5 cm (0.4-2 in) long and few, so the bushy flowering top dominates the plant. In late summer and autumn the branch tips carry many small yellow flower heads 4-8 mm wide, each combining short ray florets and a central disc, typical of the daisy family. Dry one-seeded fruits follow and scatter as the stiff, dead skeleton breaks up and tumbles. Amphiachyris spp. grows on prairies, limestone outcrops, roadsides, and overgrazed or disturbed ground, completing its whole life cycle in a single season. It grows densely on poor, dry, calcareous soils and increases where grazing or drought thins the grass cover. The plants flower most heavily in open sun and fade where taller vegetation shades them out.

Native Range

Native to the south-central United States, including Texas, Oklahoma, and neighbouring states, growing on prairies, rocky outcrops, and disturbed ground.

Suggested Uses

Grown occasionally in native prairie and wildflower plantings for late-season yellow flower and as a nectar source for insects. On grazing land it is more often managed as a weed of poor, overgrazed ground.

How to Identify

Recognized by a single slender stem that branches into a rounded, broom-like top in the upper half, with few narrow leaves below. Many small yellow daisy heads 4-8 mm wide cover the branch tips in late summer and autumn. The dry, stiff dead plant breaks off and tumbles to scatter seed.

Appearance

Size & Dimensions

Height8" - 3'3"

Width/Spread6" - 1'6"

Colors

Flower Colors

yellow

Foliage Colors

green

Bloom Information

Bloom Period

~8 weeks

Summer Fall

Many small yellow flower heads open from late summer into autumn across the broom-like crown. Each head has short ray and disc florets and draws bees and other insects. Seed ripens quickly, and the whole plant dies as the season ends.

Detailed Descriptions

Foliage Description

green

Growing Conditions

Sun Requirements

SunFull Sun

Requires 6-12 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 Range6.5 - 8.0(Alkaline)

357912

Soil Types

rocky loam clay chalk

Drainagewell drained

Water & Climate

Water Needs

Low

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

This annual grows in full sun on dry, poor, sharply drained soils, especially thin limestone and calcareous ground, and tolerates heat and drought. It germinates in spring, flowers in late summer and autumn, then dies, relying on self-sown seed for the next year. No feeding or watering is needed, and rich soil only produces soft, leafy growth. The plant increases on overgrazed pasture and bare ground where grass is thin. It fails in shade and in moist, fertile, crowded sites.

Pruning

No pruning is needed for this short-lived annual. Cutting or mowing the plants before seed ripens limits their spread on pasture and disturbed ground. The dead stems can be cleared at the end of the season.

⚠️ Toxicity Warning

Unknown

Annuals

Amphiachyris spp.

Asteraceae South-central United States

Attracts Pollinators Drought Tolerant

Native to North America

SunFull Sun

WaterLow · drought-tolerant

Overview

Native Range

Native to the south-central United States, including Texas, Oklahoma, and neighbouring states, growing on prairies, rocky outcrops, and disturbed ground.