Josef Franz Freyn (7 December 1845, Prague – 16 January 1903, Prague-Smíchov) was an Austrian civil engineer and botanist.
He was the son of the Austrian forester Josef Freyn from Obecnic. In 1856-1862 he attended the Oberrealschule in Prague. After that, he studied at the technical Polytechnic (technische Hochschule) in Prague, but interrupted his study for a placement in forestry. In 1865-1867 he studied engineering at the technical Polytechnic (technische Hochschule) in Vienna. Afterwards he was employed in the construction of railways in Hungary and later worked in Istria (1874–1878), and in the meantime conducted investigations of regional flora. In 1878 he relocated to Opočno, later returning to Prague (1881), where he owned a construction company.[1][2]
As a botanist Freyn was self-taught — he reportedly never attended a formal lecture on botany.[1] In addition to research of Hungarian and Istrian flora, he processed botanical collections from the Iberian Peninsula, Bosnia-Herzegovina, Turkestan et al. He acted as an intermediator to the plant collector Ferdynand Karo and supported him with the curation, identification and the distribution of his plant material in exsiccata-like specimen sets under the title F. Karo Plantae Dahuricae.[3] As a botanical collector he collaborated with Joseph Friedrich Nicolaus Bornmüller, Eduard Hackel, Paul Sintenis.[4] and J. J. Manissadijan[5] Freyn is remembered for his specialized studies of individual plant species, especially those within the genera Ranunculus and Hieracium.[2] An obituary was published by Eduard Hackel.[6]