Ragged Rock Flower

Crossosoma bigelovii

a) newly opened flower, b) unopened bud, c) mature fruit with three distinct carpels.

RANGE: Steep, north-facing mountain sides or within deep narrow canyons across southern Arizona. Often growing straight out of crevices.

UNARMED

SHRUB: Flexible branches may reach 2.5 m.

FLOWERS: Showy, often fragrant, white flowers with five petals. Blooms early in year, usu. Jan. to Mar.

FRUIT: 2 to 5 erect, separate ovaries develop from each flower. Later, these mature into dry capsules each with several seeds.

LEAVES: Elliptic and small, 3 cm or less.

When Crossosoma is blooming, Orange Tip Butterflies are also on the wing in the Sonoran Desert. The Sara Orange Tip (Anthocharis sara) has the base color white and the wing tips orange. The Pima Orange Tip (Anthocharis pima) has the base color yellow, and again wing tips are orange. The butterflies feed as caterpillars on winter and early spring mustards that grow about the same time that Ragged Rock Flower is blooming.

Family: Crossosomataceae

More Information:

• USDA Plant Profile
• Jepson Treatment
• Google Images
• Google Scholar Literature Search

Ragged Rock Flower growing from crevices in a rocky ledge.