saxifrage (redirected from breakstone)

saxifrage (săk`sĭfrĭj), common name for several members of the Saxifragaceae, a family of widely varying herbs, shrubs, and small trees of cosmopolitan distribution. They are found especially in north temperate zones and include many arctic and alpine species. Most American species are native to the West. The true saxifrages (genus Saxifraga and some species of other genera), also called rockfoils, comprise a large group of low rock plants including several species cultivated as rock-garden and border plants—e.g., the strawberry geranium (S. sarmentosa) native to E Asia, which propagates by runners like the strawberry. Among American wildflowers are the Eastern early saxifrage (S. virginiensis) and a Western species called umbrella plant (S. peltata). The genus also includes the arctic and alpine S. oppositifolia, one of the northernmost (found on Ellesmere Island, for instance) of flowering plants. In the old doctrine of botanical naming, the saxifrage [Lat.,=rock-breaker], because of its apparent ability to split rocks in rooting, was prescribed medicinally for calculous formations, such as gallstones. Other American wildflowers of the family include the miterwort, or bishop's cap (genus Mitella), named for its cap-shaped fruit capsule; the false miterwort, or foamflower (Tiarella); the grass-of-Parnassus (Parnassia palustris) of swamps and moist meadowlands; and the alumroot (genus Heuchera). H. sanguinea, called coral-bells, is a delicate ornamental with bright red flowers, native to New Mexico and Arizona. The other wildflowers of this group grow chiefly in rich woodland areas of the Northeast and the far West. The mock orange, or syringa, is a genus (Philadelphus) of deciduous shrubs native to Eurasia and North America. It is easily cultivated and has white blossoms generally similar to orange blossoms. One of the most popular fragrant species is the common, or sweet, mock orange (P. coronarius). Syringa [New Lat., from Gr.,=pipe], an early name for mock orange, is now the scientific name for the unrelated lilac; both bushes are also sometimes called pipe tree. Among other shrubs of the saxifrage family cultivated as ornamentals are the deutzia, any species of the Asian genus Deutzia; and the hydrangea, American and Asian plants of the genus Hydrangea with flat-topped clusters of white, pink, or blue flowers. (The blue flowers are sometimes obtained by putting alum or iron in the soil.) Of minor economic importance is the genus Ribes, a group of berry-bearing shrubs, yielding the gooseberry and the currant, to name a few. Some botanists divide the family into three smaller families but all share common features. The Saxifragaceae are classified in the division Magnoliophyta, class Magnoliopsida, order Rosales.

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saxifrage

Any of about 300 species of the genus Saxifraga, of the family Saxifragaceae, which is composed of 36 genera of mostly perennial herbaceous plants. Members of the saxifrage family are known for their ability to grow and thrive on exposed rocky crags and in fissures of rocks. They are adapted to the full range of moisture conditions, but most grow in moist, shaded woodlands in northern cold and temperate regions. Leaves characteristically alternate along the stem and sometimes are deeply lobed or form rosettes. Flowers generally are borne in branched clusters and range in colour from greenish to white or yellow and from pink or red to purple. The fruit is a capsule. Saxifraga species are planted in rock gardens or as border ornamentals, prized for their small, bright flowers, fine-textured foliage, and early spring flowering. Other well-known genera in the saxifrage family are Astilbe, Heuchera, and Mitella.

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saxifrage

any saxifragaceous plant of the genus Saxifraga, having smallish white, yellow, purple, or pink flowers