Cistus
Sp. Pl. 1: 523. 1753.
Gen. Pl. ed. 5, 234. 1754.
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.
Distribution
Introduced; Calif., Europe, n Africa, Mediterranean areas.
Discussion
Species 20 (5 in the flora).
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
Lower Taxa
Key
| 1 | Petals pink, purple, or reddish; styles 1–3+ mm. | Cistus incanus |
| 1 | Petals white, sometimes with red or yellow near bases; styles 0–0.5 mm | > 2 |
| 2 | Leaves petiolate; blade 1-veined from base. | Cistus salviifolius |
| 3 | Inflorescences solitary flowers; sepals 3; petals 30–50 mm; capsules 6–12-locular. | Cistus ladanifer |
| 3 | Inflorescences usually cymes; sepals 5; petals 10–25 mm; capsules 5-locular | > 4 |
| 4 | Leaf blades oblong-ovate to oblong-linear, (5–)10–20+ mm wide, margins not notably revolute, usually ciliate. | Cistus psilosepalus |
| 4 | Leaf blades lanceolate-linear to linear, 1–7(–13) mm wide, margins usually revolute, not notably ciliate. | Cistus monspeliensis |