Cistus ladanifer aka Common Gum Cistus

Cistus ladanifer, or common gum rockrose, is an evergreen shrub. It belongs to the rockrose family, Cistaceae. Its native range covers southwest Europe and northwest Africa. Records include Spain, Portugal, France, Morocco and Algeria. It grows in pine woods, scrub and dry, often granite hills. In gardens, it reaches about 3–5 feet (0.9–1.5 metres) tall. One source gives a spread of 3.3 feet (1 metre). Growth is fast, and leaves remain through the year.

Young branches and leaves feel sticky from their resin. The narrow, pointed leaves grow in opposite pairs. They have little or no leaf stalk. Their upper sides lack hairs, while grey hairs cover the undersides. Each leaf measures about 1.6–3.1 inches long. This resin is called ladanum or labdanum. Leaf glands yield it, with production highest during hot weather.

Large white flowers grow singly on short branches. Each has five petals and three sepals. A red-brown mark sits at each petal's base. Flowers span about 2.8–3.9 inches across. Each bloom lasts one day, but more follow in succession. PFAF lists flowering in June and seed ripening in August. Bees pollinate the flowers, which carry both male and female organs. The plant can also set seed through self-fertilisation.

Choose full sun and soil that drains well. Sandy or loamy soil suits it, even with few nutrients. It accepts mildly acid, neutral and mildly alkaline conditions. Established plants cope with drought and some coastal exposure. A sunny woodland edge is one suggested garden setting. Hardiness reports differ: Oregon State gives USDA zone 8. PFAF lists zones 6–9 and survival near 14°F (−10°C). It also advises protection during severe winters. The roots dislike disturbance, and older plants resent pruning. Keep shaping light, removing dead, damaged or stray growth.

The flowers offer value for bees and other wildlife. The resin has uses in soap, perfume and fumigation. Ground seeds can be mixed with flour for bread or cakes. Resin also serves as a food flavouring. Reports of sweet manna may refer to this same resin. PFAF records traditional medicinal uses for the leaves and resin. These include use for cough-related mucus and diarrhoea. Such records do not establish safe or effective home treatment. PFAF lists no known hazards, but gives no pet-safety assessment. The supplied sources name no specific pests or diseases.