1. Cistus Linnaeus, Sp. Pl. 1: 523. 1753; Gen. Pl. ed. 5, 234. 1754.
Rockrose [Ancient Greek name for plants of the genus] Rockrose [Ancient Greek name for plants of the genus]
John L. Strother
Shrubs, 5–25 dm, <hairy, hairs simple, sometimes clustered (stellate), glandular and eglandular>. Leaves opposite, petiolate or sessile; blade 1- or 3-veined from base, margins sometimes revolute and/or undulate. Inflorescences solitary flowers or corymbiform, scorpioid [paniculiform or racemiform] cymes. Pedicels present or absent; bracts present or absent. Flowers chasmogamous; sepals <tardily falling>, 3 or 5; petals [0 or] (4–)5, pink, purple, red, or white, <sometimes drying yellowish>; stamens [50–]100–150+; <filaments distinct or basally connate>; carpels 5 or 6–12; styles 0 or 1, <to 0.5 or 1–3+ mm>; stigmas 1, <capitate or truncate>. Capsules 5–12-valved. Seeds 10–800+ per capsule. x = 9.
Species 20 (5 in the flora): introduced, California; Europe, n Africa; Mediterranean areas.
Species of Cistus are grown as ornamentals in warm climates. Cultivars (some hybrids) are California. Leaves of Cistus incanus and C. ladanifer are the source of a scented resin, labdanum or ladanum, which may be the myrrh of ancient references. Cistus is not the source of the opiate laudanum.
SELECTED REFERENCES Dansereau, P. M. 1939. Monographie du genre Cistus L. Boissiera 4: 1–90. Guzmán, B. and P. Vargas. 2005. Systematics, character evolution, and biogeography of Cistus L. (Cistaceae) based on ITS, trnL-trnF, and matK sequences. Molec. Phylogen. Evol. 37: 644–660.