October 2013 Plant Highlight: Cleistocactus icosagonus

by Brian Kemble

Cacti with golden yellow spines are always appealing, especially when the light catches the spines and sets them aglow. A fine example is Cleistocactus icosagonus, from the Andes in northern Peru and southern Ecuador. Though presently included in the genus Cleistocactus, this species has at various times been put in other genera, including Seticereus, Borzicactus and Loxanthocereus.

C. icosagonusC. icosagonus flowers


Cleistocactus icosagonus is a clumping species with cylindrical stems which are initially upright and eventually sprawling to the side with the end portion erect. The stems can attain a length of up to 2 feet (60 cm) or more, with a diameter of 1¼ to 2¼ inches (3 to 5.5 cm). They are densely covered in golden yellow spines. On younger stems the spines are quite short, but once they get old enough to flower the spines become longer and bristly.

C. icosagonus flowers
At The Ruth Bancroft Garden, Cleistocactus icosagonus begins flowering in summer and produces multiple flushes of blooms through to early fall. The tubular red-orange flowers, 2¾ inches long (7 cm) and flared at the mouth, emerge a little below the ends of the stems. The golden spines together with the red-orange flowers makes a vivid impression. In other forms of the species the flower color ranges from orange to red, and the flower length may be up to a little over 3 inches (8 cm).

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Mission Statement
The mission of the Ruth Bancroft Garden, Inc. is to preserve this exceptional example of garden design and to continue to develop its collection of water-conserving plants for the education and enjoyment of the public.  
Grant Funders

The Ruth Bancroft Garden would like to recognize the following grant funders:

The Quest Foundation for funding our Education Coordinator’s position

The Mervyn L. Brenner Foundation and The Stanley Smith Horticultural Trust for funding our directional signs

The California Horticultural Society for funding towards our restoration projects

The Bonita Garden Clubfor funding restoration and education projects


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