Psorodendron schottii
indigo-bush
Sonoran Desert of the southwestern United States and Mexico
Overview
Psorodendron schottii, indigo bush, is a densely and intricately branched desert shrub of the Sonoran Desert, growing 3–8 feet (0.9–2.4 m) tall and nearly as wide. Its slender green, gland-dotted stems carry out much of the photosynthesis, and the small narrow leaves 0.5–1.5 inches (1.5–4 cm) long drop quickly in drought, leaving the shrub looking nearly leafless. In spring, and again after summer rains, the branch tips bear short spikes of indigo-blue to purple pea flowers about 0.3 inch (8 mm) long that draw native bees. The flowers give way to small gland-dotted pods, and the crushed foliage and stems carry a resinous scent. The shrub grows from a deep root system that lets it endure intense heat, drought, and alkaline desert soils. It is found on sandy flats, washes, and gravelly slopes across Arizona, southeastern California, and northwestern Mexico. Frost damages the stem tips, limiting it to low desert and warm climates. Its open, spine-tipped branches form a loose, irregular outline.
Native Range
Psorodendron schottii is native to the Sonoran Desert of the southwestern United States and northwestern Mexico, including southern Arizona, southeastern California, and the states of Sonora and Baja California. It grows on sandy flats, desert washes, and gravelly slopes below about 1,500 feet (460 m).Suggested Uses
Used in desert and xeriscape gardens, native habitat plantings, and erosion control on dry slopes and washes. It suits low-water landscapes and pollinator plantings in hot climates, though its frost sensitivity and open form limit where it is placed.How to Identify
Appearance
Size & Dimensions
Height3' - 8'
Width/Spread3' - 6'
Bloom Information
Indigo to purple pea flowers open in spring, roughly March through May, and again after summer monsoon rains. The short flower spikes appear at the branch tips over several weeks. Small gland-dotted pods follow and ripen quickly in the desert heat.
Detailed Descriptions
Flower Description
Indigo-blue to purpleFoliage Description
GreenGrowing Conditions
Sun Requirements
Requires 8-12 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