Silver Thistle
Carlina acaulis
Known as the 'barometer flower' because its outer bracts fold shut when humidity rises, reliably predicting rain.
- Scientific name
- Carlina acaulis
- Taxonomy
- Plantae › Tracheophyta › Magnoliopsida › Asterales › Asteraceae › Carlina
- IUCN Red List status
- Least Concern
- Population trend
- stable
- Biome
- grassland
- Habitat
- Alpine and subalpine calcareous grasslands, pastures, and stony mountain slopes.
- Diet
- Photoautotrophic (sunlight, carbon dioxide, water, and soil minerals)
- Range
- Alps, Pyrenees, Carpathians, Apennines, Balkans
- Size
- Rosette up to 30 cm wide, flower head 5 to 15 cm in diameter, virtually stemless
- Lifespan
- Perennial, typically living 5 to 15 years
- Active
- diurnal
- Threats
- Habitat loss due to agricultural intensification, overgrazing, and unsustainable wild-harvesting for ornamental use.
- Safe to approach?
- Harmless but spiny. Avoid stepping on or handling the sharp, needle-like leaves with bare hands. Safe to observe and photograph. If pricked by the spines, wash the skin with soap and water to prevent minor irritation.
Carlina acaulis ( stemless carline thistle , dwarf carline thistle , silver thistle ) is a perennial dicotyledonous flowering plant in the family Asteraceae, native to alpine regions of central and southern Europe. The specific name acaulis (New Latin for "without a stem," from Latin caulis "stem" or "stalk") and common names are descriptive of the manner in which its flower head rests directly upon a basal leaf rosette.
Photo: Udo Schmidt, CC-BY-SA, via iNaturalist
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