Mentzelia involucrata
sand blazingstar
Overview
Mentzelia involucrata is a desert annual in the stickleaf family, growing 4-16 inches (10-40 cm) tall with branching, whitish stems. The gray-green leaves are lance-shaped to triangular, 1-3 inches (2.5-7.5 cm) long, with toothed margins and barbed hairs that cling to clothing and fur. The flowers are large for the plant, 1-2 inches (2.5-5 cm) across, with five pointed cream to pale yellow petals marked by narrow red to orange veins, and they are cradled by toothed, papery bracts that give the species its name. It germinates after autumn and winter rains and flowers from February to April across the Sonoran and Mojave deserts of the southwestern United States and Baja California, growing in sandy washes, gravelly flats, and rocky desert slopes. Flowers open in the afternoon and close by evening. In dry years plants remain small with few flowers, while wet winters bring taller, many-flowered plants. As a winter annual it dies after setting its barbed-coated seed capsules. It tolerates intense sun, heat, and drought but needs sharp drainage and fails in heavy or irrigated soils.
Native Range
Mentzelia involucrata is native to the deserts of the southwestern United States, including southern California, Arizona, and Nevada, and into Baja California, Mexico. It grows in sandy washes, gravelly flats, and rocky slopes of the Sonoran and Mojave deserts.Suggested Uses
Mentzelia involucrata is used in desert wildflower plantings, gravel gardens, and native seed mixes in arid regions. It is sown 6-8 inches (15-20 cm) apart in drifts for spring bloom. It is suited only to hot, dry, sharply drained sites.How to Identify
Appearance
Size & Dimensions
Height4" - 1'4"
Width/Spread4" - 10"
Bloom Information
Flowering runs from February to April, triggered by autumn and winter rains. Flowers open in the afternoon and close in the evening, with each plant blooming over about six weeks in favorable years. Dry winters shorten and reduce the bloom.
Detailed Descriptions
Flower Description
Cream to pale yellow with reddish veinsFoliage 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
Water & Climate
Water Needs
Drought Tolerance
Drought tolerant when established
Care & Maintenance
Care Guide
Mentzelia involucrata grows in full sun in sandy or gravelly, sharply drained soil with a pH from about 6.5 to 8.0. As a desert winter annual it needs only the moisture of cool-season rains and rots in heavy or irrigated ground. Seed is sown in autumn to early winter where plants are to grow, matching the natural germination cue. No fertilizer is needed in lean desert soils. Plants die after setting seed and may self-sow where drainage and sun are adequate. It withstands heat and drought but does not persist in watered garden beds.Pruning
Mentzelia involucrata needs no pruning as a small annual. Spent plants can be cleared once they have set seed, with some left to self-sow. No deadheading is required for continued bloom.✓ Toxicity
Non-toxicPlanting Guide
Planting Methods & Timing
Planting Method
direct sow
Direct Sow Timing
Autumn to early winter in desert regions for spring bloom
Days to Maturity
70–100 days
Plant Spacing
8 inches