Plants (3-)5-35 dm. Aerial flowering stems 1-3 dm, tomentose to glabrate. Leaves: petiole 1-3 cm; blade oblong-ovate to ovate, 3-7(-10) × 2-5 cm. Inflorescences open, 10-50(-80) cm wide. Involucres 3-4 mm. Flowers 2-2.5 mm. Achenes 2-2.5 mm. 2n = 40.

Flowering year-round. Rocky cliff faces, slopes, and ridges, coastal scrub communities, oak woodlands; of conservation concern; 0-500 m; Calif.

Variety giganteum occurs naturally only on Santa Catalina Island, Los Angeles County. Mainland introductions occur from Santa Clara County to Los Angeles County; the variety has also been introduced onto Santa Cruz Island, where it threatens the genetic purity of E. arborescens. Garden hybrids between var. giganteum and E. arborescens have been named E. ×blissianum H. Mason.