Onosma frutescens aka Rocky Golden Drop

Onosma frutescens is a small perennial in the borage family, Boraginaceae. Its native range runs from central and southern Greece to Israel. It grows in a temperate climate across this range. Wild plants grow on limestone slopes and among rocks. These sites reach about 5,250 feet [1,600 metres] above sea level. The plant reaches about 1 foot [0.3 metres] tall. Its low size suits rock gardens and wall crevices.

Bristles cover the stems and leaves and can irritate skin. This is worth noting when choosing a planting spot. It flowers from June to August. Each flower has both male and female organs. Insects pollinate the flowers. The supplied species records do not describe flower colour or fruit. They also give no mature spread or details of leaf shape. The RHS calls this plant golden drop, but leaves its name status unresolved.

Grow it in full sun, with soil that drains well. It does not grow in shade. Sandy and loamy soils both suit it. Plants For A Future favours deep, fairly rich sandy loam. The plant accepts mildly acid, neutral, and mildly alkaline soil. It can grow in either dry or moist soil. Once established, it tolerates drought as well as hot, dry conditions. Wet winters and wet summers do not suit it. Good drainage therefore matters as much as the soil type.

A rock crevice or wall offers a suggested garden setting. Plants For A Future also lists beds and south- or west-facing walls. It values the species as an ornamental plant. The same source reports hardiness to about 5°F [−15°C]. It lists USDA zones 7–10. For propagation, it describes taking cuttings in summer under a frame. Keep these shaded for the first ten to twelve days. Its seed-sowing guidance is tentative, rather than based on species-specific information.

Plants For A Future records no known edible or medicinal uses. Its root yields a red dye used in place of alkanna. That use does not establish that any part is safe to eat. The stated handling hazard concerns skin irritation from the bristles. The supplied records name no insect pests or specific diseases. They do identify excess moisture as a growing concern.