Black and white vignette studio portrait of Justus Karl Hasskarl. Pencil inscription on verso, 'Dr JK Hasskarl, born Dbr 6th 1811'. Printed inscription on verso, 'Atelier fur Photographie von F. Hax Bonn No. 71, Siiirst No. 71, hinter'm Munster.'. Justus Karl Hasskarl (1811-1894) was a German explorer and botanist specialising in Pteridophytes, Bryophytes and Spermatophytes. He was co-founder of the Society of Natural Curiosities of India, in Bavaria, and Director of the Buitenzorg Botanic Garden (now the Bogor Botanical Gardens) in Indonesia.. Justus Karl Hasskarl (1811-1894) was a German explorer and botanist specialising in Pteridophytes, Bryophytes and Spermatophytes. He was co-founder of the Society of Natural Curiosities of India, in Bavaria, and Director of the Buitenzorg Botanic Garden (now the Bogor Botanical Gardens) in Indonesia.