Helminthotheca spp.

bristly oxtongue

Attracts Pollinators Attracts Butterflies

WaterLow

Overview

Helminthotheca spp. is a small genus of bristly annual to biennial herbs in the daisy family, Asteraceae, native to the Mediterranean region and Europe. The plants are covered in stiff, hooked bristles, and the leaves often bear raised whitish blisters that give the foliage a rough, warty surface. Branching stems grow 1-3 feet (30-90 cm) tall, occasionally taller, from a coarse basal rosette. From summer into autumn the stems carry pale to bright yellow heads 0.8-1.2 inches (2-3 cm) across, made up of strap-shaped florets and backed by a ring of broad, heart-shaped outer bracts. The common species H. echioides, bristly oxtongue, is a widespread weed of roadsides, field margins, and waste ground, and has naturalized across much of North America and Australia. Plants set large amounts of wind-borne seed and colonize bare, disturbed soil. The hooked bristles cling to clothing and skin.

Native Range

Native to the Mediterranean Basin and temperate Europe, on disturbed ground, roadsides, field edges, and rough grassland, often on clay or calcareous soils. The genus has naturalized widely in North America, southern Australia, and other temperate regions.

Suggested Uses

Rarely planted by choice, the genus appears in rough meadow and disturbed-ground settings where its yellow heads feed bees and other insects. Seed heads draw goldfinches and other small birds. In managed gardens it is usually treated as a weed of open soil.

How to Identify

Recognized by harshly bristly stems and leaves studded with raised whitish blisters, each blister often tipped with a hooked bristle. The yellow heads are cupped by a few broad, heart-shaped outer bracts, unlike the narrow bracts of true hawkbits. Touching the foliage leaves a rough, clinging sensation.

Appearance

Size & Dimensions

Height1' - 4'

Width/Spread1' - 2'

Colors

Flower Colors

yellow

Foliage Colors

green

Bloom Information

Bloom Period

~12 weeks

Summer Fall

Flowering runs through summer and into autumn, roughly June to October. Heads open in sunshine and close in dull weather, each lasting only a day or two before the head sets seed. Bloom continues until frost in mild areas.

Detailed Descriptions

Foliage Description

green with whitish blotches

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 Range6.0 - 8.0(Neutral)

357912

Soil Types

clay loam sand

Drainageaverage

Water & Climate

Water Needs

Low

Care & Maintenance

Care Guide

The plant grows in full sun on a wide range of soils, including heavy clay and dry, stony, or calcareous ground. It tolerates drought and poor fertility and needs no irrigation in most climates. Seed germinates on bare soil, and plants flower in their first or second year before dying. Damp, fertile ground produces larger, leafier plants. Because seed is plentiful and wind-borne, volunteers appear readily on open ground. Cutting plants down before seed ripens limits their spread.

Pruning

No pruning is needed for this short-lived plant. Cutting or pulling stems before the heads set seed is the main way to limit self-sowing. Dead plants are cleared once they brown at the end of the season.