Rockroses Cistus

The US Forest Service placed curly rockrose, Cistus crispus, in its good-performance table for southern California brushland clearings. That is a field-performance finding for a particular plant and setting. In the same publication, salvia cistus appears among plants considered unsuitable for reducing fire hazards. Its fine foliage and numerous small twigs led the authors to describe it as probably at least as flammable as Cistus villosus.

Purple cistus has favorable listings, including FireSmart BC’s fire-resistant plant chart. FireSmart BC also flags it as needing more research. That qualification should remain attached to its favorable inclusion.

The split cannot be resolved by the common name “rockrose.” Cistus consists of shrubs in the Cistaceae family, but a good field result for curly rockrose, an unfavorable evaluation of salvia cistus, and a qualified listing for purple cistus answer different parts of the fire-resistance question.