Chorizanthe rigida
Devil's spineflower
Overview
Chorizanthe rigida is a small desert annual in the buckwheat family, native to the deserts of the southwestern United States. It grows only 1-6 inches (2.5-15 cm) tall as a stiff, much-branched little plant with reddish stems and a few oblong, green to reddish leaves 0.5-1.5 inches (1-4 cm) long near the base. Tiny yellowish to reddish flowers, each only about 0.1 inch (2-3 mm) long, are clustered among bracts tipped with sharp, rigid spines. After the plant dries in late spring, the spiny, blackened skeleton remains standing for months, often persisting into the next season and giving the plant its common name. It germinates with winter rain and flowers from March to May across the Mojave and Sonoran deserts, growing on sandy and gravelly flats, desert pavement, and rocky slopes. In dry years plants are minute; wet winters allow larger, bushier growth. As a winter annual it completes its life cycle in a single season. It tolerates extreme sun, heat, and drought but needs sharp drainage and open, unshaded ground. The persistent spiny remains help shelter the seeds dropped beneath them.
Native Range
Chorizanthe rigida is native to the deserts of the southwestern United States, including California, Nevada, Arizona, and Utah, and into northwestern Mexico. It grows on sandy and gravelly flats, desert pavement, and rocky slopes in the Mojave and Sonoran deserts.Suggested Uses
Chorizanthe rigida is used in desert restoration plantings and native seed mixes rather than ornamental beds, because of its small size and spiny dried form. It is sown thinly in open, gravelly ground. It suits only hot, dry, sharply drained desert sites.How to Identify
Appearance
Size & Dimensions
Height1" - 6"
Width/Spread1" - 4"
Bloom Information
Flowering occurs in spring, from about March to May, after winter rains. The tiny yellowish flowers are easily passed over among the spiny bracts. After bloom the plant dries and hardens into a persistent spiny husk.
Detailed Descriptions
Flower Description
Yellow to reddishFoliage Description
Green to reddish, drying brownGrowing Conditions
Sun Requirements
Requires 6-12 hours of direct sunlight daily
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight
Water & Climate
Water Needs
Drought Tolerance
Drought tolerant when established
Care & Maintenance
Care Guide
Chorizanthe rigida grows in full sun on sharply drained sandy or gravelly soil with a pH from about 6.5 to 8.5. As a desert winter annual it relies on cool-season rain and needs no supplemental water once established. It requires open, unshaded ground and fails in rich, heavy, or irrigated soils. No fertilizer is needed. Seed is sown in autumn to early winter where plants are to grow. Plants die after setting seed, leaving spiny remains that shelter the fallen seed until the next rains.Pruning
Chorizanthe rigida needs no pruning as a small annual. The dried, spiny skeleton can be left in place, where it shelters dropped seed, or cleared once seed has fallen. No deadheading is done.✓ Toxicity
Non-toxicPlanting Guide
Planting Methods & Timing
Planting Method
direct sow
Direct Sow Timing
Autumn to early winter in desert regions for spring germination
Days to Maturity
60–90 days
Plant Spacing
4 inches