Belgian botanist (1779 - 1858).
Alexandre Louis Simon Lejeune (23 December 1779 in Verviers – 28 December 1858 in Verviers) was a medical doctor and botanist. In 1801 he entered the school of medicine in Paris, but was subsequently forced to abandon his studies due to military conscription. After finishing his military duties in late 1804, he relocated to Ensival as a physician. Three years later, he settled permanently in his hometown of Verviers. With Richard Courtois (1806–1835), he was co-author of "Compendium florae belgicae". He was a mentor to Marie-Anne Libert, who he introduced to Augustin Pyramis de Candolle. Liber