# Silver Thistle

*Carlina acaulis*

Known as the 'barometer flower' because its outer bracts fold shut when humidity rises, reliably predicting rain.

- **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.

## About

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.

## Sources

- Plate: https://gaia-dex.com/species/066616d1-1caf-46a6-b053-766e9387c6ba
- iNaturalist: https://www.inaturalist.org/taxa/56299
- Wikipedia: https://en.wikipedia.org/wiki/Carlina acaulis
- Conservation status: IUCN Red List category, as recorded by Gaia-Dex
- Photo: https://inaturalist-open-data.s3.amazonaws.com/photos/5200445/medium.jpg (Udo Schmidt, CC-BY-SA, via iNaturalist)

Habitat, diet, size and similar notes are AI-written summaries; check them against the linked sources before relying on them.