Allionia incarnata
trailing windmills
Southwestern North America and South America
Overview
Allionia incarnata is a prostrate, trailing perennial, sometimes behaving as an annual, that spreads flat across the ground on sticky-hairy stems 12-40 inches (30-100 cm) long, native to arid country of the southwestern United States, Mexico, and South America. Paired oval leaves are unequal in size, gray-green, and covered in glandular hairs that trap sand. From spring through autumn, after rainfall, magenta to rose-pink flower heads 0.5-1 inch (12-25 mm) wide open along the stems. Each apparent bloom is actually a tight cluster of three flowers fused to look like a single five-lobed pinwheel, the trait behind the common name. Flowers open in the morning and close by midday in heat. The plant roots from a slender taproot and tolerates intense sun, heat, and drought, going dormant or dying back in extended dry spells. It carries little mass and forms only thin ground coverage, leaving gaps between trailing stems. Bloom is irregular and tied to soil moisture rather than a fixed season.
Native Range
Native to the deserts and dry grasslands of the southwestern United States, Mexico, and parts of western South America, where it grows in sandy and gravelly soils from desert flats to rocky slopes.Suggested Uses
Grown in desert and rock gardens, gravel plantings, and along dry banks where it trails over stone. Suited to hot, reflected-heat sites and containers with gritty mix. Cold, damp ground and the need for solid cover restrict its use.How to Identify
Appearance
Size & Dimensions
Height2" - 4"
Width/Spread1' - 3'4"
Reaches mature size in approximately 1 years
Bloom Information
Flowering follows rainfall from spring into autumn, roughly April through October, rather than a set calendar period. Magenta to rose-pink heads open in the morning and close by early afternoon in heat. Native bees and other small insects visit during the open hours.
Detailed Descriptions
Flower Description
Magenta to rose-pinkFoliage Description
Gray-greenGrowing 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
Care & Maintenance
Care Guide
Full sun and sharply drained sandy or gravelly soil suit this desert trailer. It tolerates a soil pH from about 6.5 to 8.0 and withstands extreme heat and drought once rooted, drawing on a deep taproot. Water is needed only to trigger growth and bloom; in regular garden irrigation and heavy soil the stems rot. Growth and flowering pause during dry intervals and resume after rain. The plant is short-lived and may not persist through cold, wet winters. Aphids occasionally gather on the soft new stems.Pruning
Trailing stems can be trimmed back to keep the plant within bounds after flowering. Frost-killed growth is cleared in spring. No detailed pruning is needed.Container Growing
✓ Suitable for container growing
Minimum container size: 1 gallons