Theodor Friedrich Ludwig Nees von Esenbeck (26 July 1787 – 12 December 1837) was a German botanist and pharmacologist, who was born in Schloss Reichenberg near Reichelsheim (Odenwald).
In 1805 Nees von Esenbeck was an apprentice to pharmacist Wilhelm Martius in Erlangen, and in 1811 moved to Basel, where he worked for the Bernoulli family at the Goldenen Apotheke.
In 1827 he attained the title of "full professor" at the University of Bonn, where he was a colleague of Ludolph Christian Treviranus (1779–1864).
Nees von Esenbeck is largely remembered for pharmacological analysis and taxonomy of various medicinal plants.
[1] In the mid-1830s, with Philipp Wilhelm Wirtgen (1806–1870) and Ludwig Clamor Marquart (1804–1881), he was co-founder of the Botanischer Verein am Mittel- und Niederrhein (Botanical Society of the Middle and Lower Rhine).