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Cottontop Cactus
Scientific Name: Echinocactus polycephalus Engelm. & J.M.Bigelow
Synonym: Emorycactus polycephalus
Family: Cactaceae
Cottontop Cactus (Echinocactus  polycephalus)
Echinocactus polycephalus at the Wallace's collection in Phoenix in April
Recommended Temperature Zone:
sunset: 10-13
USDA: 8b-11

Frost Tolerance: Hardy to 10F (-12C)

Minimum Avg. Temperature: 55F (12C)

Sun Exposure: Full sun

Origin: USA (Mohave and Sonoran desert: Arizona, California, Nevada), Mexico (northwestern Sonora) at low elevations

Growth Habits: Clumping cactus, some colonies contains over 100 stems, spherical to short cylindrical stems, 12 to 24 inches tall (30-60 cm), 3.6 to 8 inches in diameter (9-20 cm); 12 to 18 ribs, 0.8 to 1.2 inches deep; large areoles, 0.4 inch in diameter (1 cm), 0.4 to 1.4 inches apart (1-3.5 cm); 4 central spines, 2 to 3.6 inches long (5-9 cm); 6 to 8 radials, 1 to 2 inches long (2.5-5 cm).

Watering Needs:


Cottontop Cactus (Echinocactus  polycephalus)

Cultural Practices:
Yellow flowers, 2 to 2.4 inches long (5-6 cm), in February and March. The fruit is dry, covered with woolly hair, opening at the base when ripe, allowing the black seeds to escape.

Blooming Habits:

Fruiting Habits:

Check for Field Collection numbers at Ralph Martin's Site

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Desert-Tropicals is dedicated to provide gardening advice, gardening ideas, and information about flower of all kind for landscape and collections. We try to check carefully the identification of the plants on the illustrations as well as the other information from the page, but occasionally errors do occur. if you notice anything that needs to be changed please contact us. Thanks.

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