Horned Poppy
Glaucium flavumPapaveraceae
Whole Plant
Whole PlantFlowerFruitFruit
Photos (c) Cheryl Comeau Beaton unless otherwise noted


  • Yellow hornpoppy, Sea poppy
  • Glaucium glaucium

The Plant:

  • A biennial or perennial herb reaching 1-3 feet tall.

The Leaves:

  • firm
  • pubescent
  • glaucous
  • basal leaves have petioles
  • stem leaves sessile
  • ovate to oblong
  • deeply toothed

The Flowers:

  • Yellow to orange four-petaled flowers with obovate petals. Flowers are terminal or axillary with thick pedicels at maturity.

The Fruits:

  • capsule long and curved, thin, green turning to brown
  • sublinear, glabrous or scabrous
  • stigma persists

The Habitat:

  • poor, sandy, and dry soils
  • coastal; beach, dunes, below cliffs, above high tide mark
  • disturbed areas
  • roadsides
  • gardens


  • seeds are dispersed short distances by the plant when pods open
  • water dispersed
  • garden escape

Key ID Features:

  • basal leaves
  • hairy, glaucuous
  • stem leaves sessile
  • yellow to orange flowers

Similar Species:

  • Celandine (Chelidonium majus) has non-hairy leaves, linear-oblong fruits
  • and .4 inches wide petals
  • Celandine poppy (Stylophorum diphyllum) has non-hairy leaves, ellipsoid shaped fruits, and .75-1.2 inches petals.


  • Horned poppy can create a monoculture eliminating native plants. It can also take over high tide areas near the shoreline and escape from garden plantings.

Growth Form: Herb

Origin: Africa, Asia, Europe

Level of Invasiveness for Nantucket: Invasive

Level of Invasiveness for Massachusetts: Invasive

Massachusetts Cultivation Restrictions: importation ban, propagation ban

Credits: The Electronic Field Guide to the Invasive Plants of Nantucket (c) 2005-2006 Maria Mitchell Association, EFG Project, UMass Boston