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Oreostemma spp.
alpine aster
Overview
Oreostemma spp. is a small genus of perennial herbs in the family Asteraceae, native to the mountains of western North America, with about three species segregated from the broad genus Aster spp.. The most familiar is O. alpigenum, the tundra or alpine aster, of subalpine and alpine meadows in the western United States. Plants grow from a branching woody base or rhizome and form low tufts of narrow, grass-like to spoon-shaped basal leaves 5-20 cm (2-8 in) long, mostly clustered near ground level. From mid- to late summer slender, nearly leafless stalks 10-40 cm (4-16 in) tall each carry a single daisy-like flower head 2.5-4 cm (1-1.6 in) across, with violet to lavender ray florets around a yellow disc. The genus is restricted to high mountains, growing in wet subalpine meadows, seepage slopes, and streamsides that are snow-covered for much of the year. The plants are adapted to a short, cool growing season and intense light, and they tolerate poor, gravelly soils kept moist by snowmelt. Because of this specialised habitat, Oreostemma spp. is uncommon in cultivation and needs cool, sharply drained, alpine-like conditions.
Native Range
Oreostemma spp. is native to the mountains of western North America, from the Pacific states inland to the northern Rockies. Species grow in wet subalpine and alpine meadows, seepage slopes, and streamsides, often where snow lies late.Suggested Uses
Oreostemma spp. is grown in rock gardens, alpine troughs, and raised scree beds by specialists who can provide cool, gritty, moist conditions. In the wild it is part of high-mountain meadow communities and is seldom seen in general garden use.How to Identify
Appearance
Size & Dimensions
Height4" - 1'4"
Width/Spread4" - 10"
Bloom Information
Flowering occurs in the mountain summer, mostly July to August, with one violet to lavender daisy head per stalk. The heads give way to small dry seeds carried by a tawny pappus, ripening before the first autumn snow.
Detailed Descriptions
Flower Description
violet to lavender with yellow discFoliage Description
greenGrowing Conditions
Sun Requirements
• Full Sun: 6+ hours of direct sunlight
• Partial Shade: 3-6 hours of direct sunlight
• Full Shade: Less than 3 hours of direct sunlight