The Autumn Crocus, also known as Meadow Saffron, is one of the most poisonous plants in the Donau-Auen National Park. Its large pale lilac flowers, which resemble those of the crocus at first glance, are a characteristic autumn sight of wetlands meadows. In fact, another common name for Colchicum autumnale is "Naked Lady" and has to do with the late blooming of the flower: where the autumn ground is bare and barren, this species flowers conspicuously and colourfully and all alone, when and where it is least expected. The fruit of the Autumn Crocus over-winters under ground and appears only in the spring along with the leaves of the plant.
A perennial, this plant grows to heights between 5 and 40cm and has a brown scaly corm that is around 7cm long. Its leaves are elongated and lancet-shaped and are up to 40cm long. The leaves are never seen simultaneously with the flowers but are present in spring and summer together with the fleshy three-part fruit capsules. Between August and November, when deciduous leaves have already fallen, the long stalk-like, light pink to purple flowers appear. The flowers have a diameter of around 1 to 3cm and have three long styles with small stigmas in the middle. The petals are arranged funnel-like to form a long "tube", similar to a crocus. During flowering, no other parts of the plant are visible above ground. More rarely, blooming Autumn Crocus can be sighted in the months of February and March.
This species' range includes Western, Central, Southern and south Eastern Europe as well as northern Africa; it may be found in lowlands and in elevations of up to 1400m above sea level. In Austria, Colchicum autumnale is found in all provinces. Its preferred locations are damp grassy meadows with nutrient-rich soils (e.g. wetlands meadows) and riparian forests, where it can be found in large colonies.
Endangerment and Conservation Status
The Autumn Crocus is vulnerable in the Pannonian Plain of eastern Austria.
The life cycle and rhythm of the Autumn Crocus varies considerably from that of most native flowering plants. The large flowers have long stalks and appear in autumn after the leaves have long wilted. Only a few other herbaceous plants bloom during this time period. Due to mowing or grazing, meadow vegetation is normally so low that the flowering Autumn Crocus simply cannot be missed – either by visitors to the National Park or by pollinating insects. Only in the following spring do the three-part fruit capsules appear together with the three main green leaves.
The Autumn Crocus contains a variety of diverse alkaloids. The most significant one is colchicine, which is found in its testa, or seed coat, but also in the bulb and leaves. The substance is most dangerous to warmblooded organisms: just 5g of seeds constitutes a fatal dose. Symptoms of poisoning occur only several hours after ingestion yet lead inevitably to death by paralysis of the respiratory system. Despite its high toxicity, the plant is used for medicinal purposes: colchicine in small doses can be used to treat gout, rheumatic complaints, skin diseases as well as gastroenteritis. However, the poison accumulates in the body when used over sustained periods. Because the level of colchicine varies from plant to plant, only the isolated active ingredient can be utilized. The ancient Greeks used the herb for medicinal purposes, particularly to relieve symptoms of gout. With their knowledge of its danger, the Greeks aptly named the Autumn Crocus "ephemoren", or "that which kills in one day". Indeed: this plant should never be consumed for medicinal (or any other) purposes unless under the strict supervision of a medical practitioner!