Species In North America, Ecological And Economic Importance
The saxifrages, currants, and gooseberries are about 40 genera and about 850 species of plants that make up the family Saxifragaceae. These plants occur in all parts of the world, but are most diverse and prominent in arctic, boreal, and montane habitats of North America and Eurasia. The largest genera in the family are the saxifrages (Saxifraga spp.), of which there are about 300 species, most of which occur in the tundras of alpine and arctic environments, and the currants and gooseberries (Ribes), with about 150 species in boreal and temperate habitats.
Most species in the saxifrage family are perennial herbs, while others are woody shrubs or small trees. Their leaves are usually simple, small, with a toothed margin or tip, and can be arranged alternately or oppositely on the stem. The flowers are perfect (that is, bisexual), containing both female and male reproductive structures. There are usually five sepals and five petals, and usually twice as many stamens as petals. The pistil usually has two (but as many as four) carpels, each with its own stigma and style, producing a distinctive, split
unit with outward-curving stigmatic tips. The fruit is a dry capsule, containing many small seeds, or in the case of Ribes, a many-seeded berry. The stems of the shrub-sized currants and gooseberries (Ribes spp.) are often armed with spines and prickles.
- Saxifrage Family - Species In North America
- Saxifrage Family - Ecological And Economic Importance
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