Colchicum speciosum Giganteum

Colchicum giganteum is a species of colchicum with large funnel-shaped flowers, unlike C. speciosum whose flowers are bell-shaped. Its flowers emerge in white in autumn, before quickly turning to pale-lilac, with a characteristic white throat. Ready to conquer a lawn, it also thrives in rockeries or on the edge of woodlands.

Colchicum giganteum, from the Colchicaceae family, is a bulbous plant native to the Caucasus, northeastern Turkey, and Iran, where it is found up to an altitude of 3000m (9842ft) in subalpine meadows. It is a spring-growing plant that goes dormant underground during summer and flowers in early autumn. It is a form with larger flowers and later flowering than C. speciosum. The foliage emerges from the ground in spring, between April and May. It consists of long lanceolate leaves measuring up to 25cm (10in) long and 8 to 10cm (3 to 4in) wide. The bright leaves are light green and glossy, grouped in a small clump resembling ornamental garlic. Flowering occurs from late September or October. Each bulb or corm produces one to three large funnel-shaped flowers, with 6 petals fused at the base into a long tube that originates from the root. They measure 7 to 8cm (3in) in diameter and transition from pure white to pale-lilac, with a white throat. A mature plant can produce up to 50 flowers. The 'bulb' is actually a corm, an underground storage organ that helps the plant to survive during unfavourable seasons. It multiplies by forming numerous small corms, allowing it to form large clumps over the years. This plant also reproduces by producing fruits, visible in spring, nestled among the leaves.

Colchicum giganteum dreads hot summer temperatures and excessively dry soils. It can be planted in rockeries, open woodlands, and less frequented areas of a lawn. Choose companion plants for their spring foliage or late flowering, such as heucheras, sedums, thymes, or Phlox subulata. It thrives in mountain climates, with summer rainfall and distinct winters, and easily naturalises. All parts of the plant are toxic, meaning it is rarely bothered by common garden predators.