Spanish: Palo santo; Rabo de iguana; Rosalillo; Tlapacon; Corona de Cristo; Flor de jabon.
Region: central and southern Mexico.
Habitat: rocky alluvial slopes and valleys; on lateritic to calcareous soils; tropical deciduous forests, arid tropical scrub vegetations; 100 to 2400 meters altitude.
BotanyTree; small, up to 8 m tall; variable.
Stem: green; 1 to 2 basal trunks; 25 to 40 cm in diameter; dichotomously branched, with numerous, erect to widely spreading young stems; periderm is smooth, dark bronze to yellow, exfoliating in thin, papery sheets; branches are covered in spines, 4 to 20 mm long.
Inflorescence: short; spicate.
Flowers: large; deep orange-red to yellow-orange; corolla decurved; stamens variable number; stamens and stigma protrude significantly from the flower tube; flowering from October through February.
Pollination: by hummingbirds, perching birds, carpenter bees, bumblebees.