Trachelium caeruleum, common name blue throatwort, is a species of flowering plant in the family Campanulaceae native to the Mediterranean, where its native range includes Algeria, Morocco, Portugal, Spain, and Sicily. It has also become naturalized in a few areas, including New Zealand, the Azores, and parts of mainland Europe.
Growing to 120 cm (47 in) tall by 30 cm (12 in) wide, it is a woody-based erect herbaceous perennial, with oval leaves and dense cushions of violet-purple flowers in summer. The specific epithet caeruleum means "dark blue".
In temperate climates this plant is usually grown as a half-hardy annual for summer bedding schemes or planters. It has gained the Royal Horticultural Society's Award of Garden Merit. There are many cultivars with a variety of flower colors, including white, red, pink, and dark purple.
- "International Plant Names Index". Retrieved 23 April 2013.
- "Trachelium caeruleum". Germplasm Resources Information Network (GRIN). Agricultural Research Service (ARS), United States Department of Agriculture (USDA). Retrieved 23 January 2018.
- RHS A-Z Encyclopedia of Garden Plants. United Kingdom: Dorling Kindersley. 2008. p. 1136. ISBN 1405332964.
- Harrison, L. (2012). RHS Latin for Gardeners. United Kingdom: Mitchell Beazley. p. 224. ISBN 9781845337315.
- "RHS Plant Selector - Trachelium caeruleum". Retrieved 5 July 2013.
- "AGM Plants - Ornamental" (PDF). Royal Horticultural Society. July 2017. p. 102. Retrieved 23 December 2018.
- Liang, R. and B. K. Harbaugh. (2001). Evaluation of Trachelium cultivars as cut flowers. HortTechnology 11(2), 316-18.