What is Androsace?

Androsace is a plant genus that is part of the Primulaceae family. It contains about 100 species of annual, perennial, and biennial herbs that are native to North America, Europe, and Asia. Most are small plants with leaves arranged in a rosette and white flowers that sit atop stems. They are generally planted in rock gardens or used as container plants. Plants of this genus grow well in sandy peat or gritty loam.

The genus name is derived from the Greek words ane and sakos, which translate to "man" and "a shield," respectively. Rock jasmine is the common name for the plants in this genus. Several species have variations of the common name. For example, Androsace septentrionalis is commonly referred to as pygmyflower rock jasmine or northern fairy candelabra, while a variety of Androsace chamaejasme is called Lehmann's rock jasmine.

Androsace is generally distributed in the mountainous regions of Europe and Asia. A few species, such as A. occidentalis, are grown in Canada and the United States. A. alpina and A. glacialis are located in the Alps of Europe, while A. lanuginosa is located in the Himalayas of Asia. Several species are located in the Pyrennes, including A. pyrenaica and A. laggeri.

A. lanuginosa features distinctive silvery shoots and pinkish-red clusters of flowers. The foliage comprises green leaves that have a hairy texture. Generally, the leaves are arranged in a circular fashion.

This species has a long bloom period which usually lasts from early spring to October. The flowers form in umbels, which is a flower arrangement that consists of a series of short flower stalks, usually of equal size, that sprout from a common point at the end of a stem. It is similar in shape to the ribs of an umbrella.

Cuttings of unflowered shoots are taken in July or August and are rooted easily in sandy soil. The cuttings are typically 2 inches (about 5 cm) long. Propagation can also take place by sowing seeds.

Depending on the type of soil, this plant can be adapted to grow as a border plant or as a specimen in a rock garden. Many of the species can grow in the fissures of rocks that contain 15 inches (38 cm) of sandy soil. A. lanuginosa can be planted with similar plants, such as A. septentrionalis.

Several pests can cause damage to rock jasmine plants including aphids, slugs, and red spiders. They damage the leaves of the plant and may leave behind secretions or webbing. Applying insecticidal soap to the plant can reduce the infestation.