Cornelius Osten (11 February 1863, in Bremen – 6 September 1936, in Montevideo) was a German businessman and botanist known for his investigations of Uruguayan flora.
He specialized in studies of the botanical family Cyperaceae (sedges).
[1] In 1896 he emigrated to Uruguay, where he worked with José Arechavaleta, director of the natural history museum in Montevideo.
His herbarium of 23,000 items was bequeathed to the natural history museum in Montevideo.
[2][3] The plant genus Ostenia (family Alismataceae) was named in his honor by Franz Georg Philipp Buchenau.