Colchicum speciosum is a species of flowering plant in the family Colchicaceae, native to mountainous areas of northern Turkey, the Caucasus and northern Iran. Growing to 18 cm (7 in) tall by 10 cm (4 in) wide, it is an herbaceous perennial growing from corms. C. speciosum blooms in the fall, producing reddish/violet flowers on stems up to 30 centimetres (12 in) tall without any leaves present. The strap-like leaves grow in the spring, then yellow, wither and die back as summer progresses. The flowers strongly resemble those of the crocus, the familiar spring-flowering bulb; hence the common name "autumn crocus" which is applied to this and other colchicum species. However the two genera belong to different families.
Colchicum speciosum is a vigorous grower and does well in full sun to partial shade and well-drained soils in most climates. It is valued in gardens for its late flowering at the end of summer and into autumn.
Cultivars include the white 'Album' and the amethyst-purple ‘Atrorubens’ which, together with their parent, have gained the Royal Horticultural Society's Award of Garden Merit (confirmed 2017).
Colchicum speciosum var. bornmuelleri (syn. Colchicum bornmuelleri Freyn) has bowl-shaped, white-throated flowers with emerald-green tube and brownish anthers.
- World checklist of selected families
- RHS A-Z encyclopedia of garden plants. United Kingdom: Dorling Kindersley. 2008. p. 1136. ISBN 1405332964.
- Steven, Christian von. 1829. Nouveau Mémoires de la Société Impériale des Naturalistes de Moscou 7: 265, t. 15.
- "RHS Plant Selector - Colchicum speciosum 'Album'". Retrieved 16 June 2013.
- "RHS Plantfinder - Crocus speciosum 'Atrorubens'". Retrieved 30 January 2018.
- "RHS Plant Selector - Colchicum speciosum". Retrieved 16 June 2013.
- "AGM Plants - Ornamental" (PDF). Royal Horticultural Society. July 2017. p. 22. Retrieved 24 January 2018.