Haussknecht specialized in the study of the genus Epilobium from the botanical family Onagraceae. In 1884 he published a monograph on the genus called Monographie der Gattung Epilobium.[3] The botanical genus Haussknechtia was named in his honour by Pierre Edmond Boissier (1810-1885) in 1872.[4]
Also he was honoured in Ferula haussknechtiiWolff ex Rech. f. in 1952.[5]
Haussknecht distributed several large series of dried plant specimens, all not being exsiccatae in the strong sense, but listed by IndExs – Index of Exsiccatae.[6] The series are entitled with reference to his expeditions, e.g., Iter Syriaco-Armeniarum (1864-1866) and Iter orientale (1867-1868).[7][8]