Glischrocaryon spp.

popweed

HardinessZones 9–11

Overview

Glischrocaryon spp. is a small genus of about four perennial herbs and subshrubs in the family Haloragaceae, native to Australia. The plants arise from a woody rootstock and send up clumps of erect, wiry, rush-like stems 8-32 inches (20-80 cm) tall that carry small, narrow or scale-like leaves, often shed or reduced on the upper stems. In spring and summer the stems are topped by branched clusters of small yellow flowers, each with four petals, that together form bright heads above the foliage. After flowering the genus produces characteristic hard, four-winged woody nutlets that persist on the stems and aid wind dispersal. Most species grow in open heath, mallee, and woodland on sandy or rocky soils in seasonally dry climates, resprouting from the rootstock after fire or drought. The narrow leaves and slender stems give the plants a sparse, almost leafless look outside the flowering period. G. behrii, called golden pennants, is grown occasionally for its yellow flower heads and winged fruit. The genus is little known in cultivation and tolerant of poor, dry ground.

Native Range

Glischrocaryon spp. is native to Australia, with species across the southern and inland parts of the continent. It grows in heath, mallee, and open woodland on sandy and rocky soils in regions with dry summers.

Suggested Uses

Grown in native Australian, dry-climate, and gravel gardens for the yellow flower heads and winged fruit. The wiry stems and persistent nutlets are cut for fresh and dried arrangements. The genus suits low-water plantings on poor sandy soils.

How to Identify

Look for clumps of erect, wiry, rush-like stems with small narrow or scale-like leaves, topped in spring and summer by branched clusters of small four-petalled yellow flowers. The hard, four-winged woody nutlets that follow are characteristic and persist on the dry stems. The sparse, near-leafless stems and yellow flower heads help identify Glischrocaryon spp..

Appearance

Size & Dimensions

Height8" - 2'8"

Width/Spread8" - 1'8"

Colors

Flower Colors

yellow

Foliage Colors

green

Fall Foliage Colors

no change

Bloom Information

Bloom Period

~8 weeks

Spring Summer

Flowering occurs in spring and summer, generally September to January in the southern hemisphere. The small yellow four-petalled flowers are massed in branched terminal clusters held above the stems. Four-winged woody nutlets develop afterward and remain through the dry season.

Detailed Descriptions

Foliage Description

green to grey-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 Range5.5 - 7.5(Neutral)

357912

Soil Types

sand rocky

Drainagewell drained

Water & Climate

Water Needs

Low

Frost Tolerance

hardy

Time to Maturity

2-3 years

Drought Tolerance

Drought tolerant when established

Care & Maintenance

Care Guide

Plants grow in full sun on sandy, gravelly, or rocky free-draining soils and tolerate heat, drought, and low fertility. Once established they need little or no irrigation, drawing on a woody rootstock that also lets them resprout after fire. Wet, heavy, or rich soils cause rot and weak growth, so lean, sharply drained ground suits the genus. Hardiness suits warm-temperate and semi-arid climates, roughly USDA zones 9 to 11, with tolerance of light frost. Propagation is from seed or from the rootstock, though plants establish slowly. Few pests affect the genus in dry conditions.

Pruning

Spent flowering stems are cut back after the nutlets have formed to keep the clump tidy. The woody rootstock resprouts, so plants tolerate being cut to near ground level. Little other pruning is needed.