Arizona Poppy

Kallstroemia grandiflora

Arizona poppy blooming at Academy Village

About the Plant

This native annual appears in abundance when the summer monsoon rains are good. Its bright orange flowers, open only during the day, are 1-2 inches wide and quite showy. Usually appearing as a wildflower, especially along roadsides, it is also possible to grow it as a reseeding annual in a landscape situation. Seeds are available for purchase at good nurseries and by mail order. Please see the information from ASU for planting directions. Also, please note that seeds exhibit dormancy and may not germinate for several years.

Notes:

  • Though called "poppy", this plant is not in the poppy family. The name is thought to derive from the superficial resemblance of the the flower to those of California poppy (Eschscholzia californica). Both have large, orange flowers. For a detailed comparison, please see the Weekly Plant article on this plant.
  • The leaves and growth form of Arizona poppy are similar to puncturevine. Both have opposite, compound, hairy leaves. Arizona poppy is overall a larger plant. Once flowering begins the small, yellow flowers of puncturevine easily distinguish the two plants.
  • Other common names for this plant include Arizona or orange caltrop and summer or desert poppy.

Wildlife value: flowers attract a number of insects including bees and butterflies. The seeds are eaten by birds, especially doves.

More Information

Weekly Plant on Arizona poppy

Horticultural information from ASU

Photos of fields of Arizona poppy after a good monsoon

Map of distribution in US (blue-green color indicate plant has been introduced to state)

Technical botanical description from SEINet

ID Characteristics

This plant is in the Zygophyllaceae - the caltrop family.
Arizona poppy blooming at Academy Village

The growth of Arizona poppy is dependent on summer rains. In a wet year, the plant can grow 2-3 feet high and 5+ feet wide. In dry years, the plants will be smaller, hugging the ground, and many seeds may not germinate at all.

The stems, as seen in this photo, are hairy as are many other plant parts.
The evenly pinnate leaves are opposite and grow to 3+ inches long and 1+ inch wide. There are 5-10 pairs of leaflets, each leaflet 1+ inches long and 1/4 inch wide. In dry summers, leaves and leaflets will be smaller. Note hairy stems and leaf edges in photo.
The flowers are held singly on a short stalk. There are 5 hairy sepals (see photo of stem above). The 5 separate petals are bright orange, often with a darker orange-red center. There are about 10 stamen, with orange anthers on long filaments. In the center is a single, long style. Flowers are usually 1-2 inches wide though a width of 2.5 inches is often listed.
The fruit retains the long style, which can be 1/2 inch long. The fruit will split into about 10 sections when it is mature. Note hairy stem and sepals.