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  4. Horned poppy
What Are Weeds?

Weed Information Sheet

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Horned poppy

Botanical Name

Glaucium flavum

Family

Papaveraceae (poppy)

Also known as

Sea poppy, yellow hornpoppy, G. luteum

Where is it originally from?

Western Europe, Mediterranean, South Western Asia

What does it look like?

Annual or perennial herb which starts as a tufted rosette, then produces stout, erect, hairless, bluish-green stems (20 cm to 50 cm tall). Leaves are also bluish-green, with very deeply lobed or toothed lower leaves (<50 cm long x 10 cm wide) that are hairy on both surfaces. Upper leaves are smaller, egg-shaped or triangular, hairy above and almost hairless below, shallowly lobed and without leaf stalks. Flowers are held individually on short, hairless stalks (1-2 cm long). Sepals are hairy, and the flowers made up of four overlapping yellow petals (30mm x 40mm, Nov-Mar) and develop into long seed capsules (<30 cm long and 0.7 mm wide) with warty surfaces.

Are there any similar species?

Californian poppy has more highly divided leaves, watery sap and short, thick seed capsules that split into two parts.

Why is it weedy?

Withstands hot, dry conditions and thrives in poor soils. Frost tolerant.

How does it spread?

Seed spread by water.

What damage does it do?

Outcompetes small native grasses and herbs on poor soils.

Which habitats is it likely to invade?

Bare, gravelly or sandy, dry or well-drained soils with high light levels such as rocky and shingly coast line, coastal cliffs, dunes and braided rivers.

What can I do to get rid of it?

Pull out small patches (spring-summer).

What can I do to stop it coming back?

Monitor the site and pull out any seedlings. Where appropriate plant local native plants to produce shade.

Images

Photo: Carolyn Lewis
Photo: Carolyn Lewis
Photo: Trevor James
Photo: Trevor James
Photo: Trevor James
Photo: Trevor James
Photo: Trevor James
Photo: Trevor James

Download PDF Information Sheet

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  • Home
  • Weedbusters
    • Who are Weedbusters?
  • What Are Weeds?
    • Weed List
    • Controlling Weeds
      • Controlling Pest Shrubs & Trees
      • Controlling Pest Vines
      • Controlling Pest Herbs & Ground Covers
      • Controlling Pest Grasses
      • Controlling Pest Aquatic Weeds
    • Disposing of Weed Waste
    • Banned Plants
  • Get Involved
    • Become a Weedbuster
    • Weedbusters Near You
    • Weed Quiz
  • Resources
    • How to…
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    • Weedbusting Guide
    • Plant Me Instead Booklet
    • Using Weedbuster photographs
    • Useful Links
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