This registered self-printed cover has a red registration label ‘Queensland/ Brisbane’ with five stamps totaling seven pence, made up of two 2d red KGV head stamps as well as three 1d purple KGV stamps, individually cancelled REGISTERED BRISBANE/ 15 SE 22/ QUEENSLAND, and it is addressed to C.C. Hosseus, Casilla de Correo 74, Cordoba, Rep. Argentina, South America (Figure 1).
The reverse has the same origin postmark, a transit REGISTERED/ SYDNEY postmark, as well as a transit BUENOS AIRES/ 2 XI 22/ ARGENTINA and two identical reception postmarks of CORDOBA/ 2 NOV/ (–) (Figure 2).
Carl Curt Hosseus was born in Stromberg im Thale, Rhineland, Germany in 1878 and died in Cordoba, Argentina in 1950. He was a botanist who took his Ph.D. degree in 1903, and he left Genoa in June 1904, travelled to Thailand ( Siam) in 1904-05 where he found Viola hossei, which was named after him. He was the first botanist ever to collect in Northern Thailand, earlier than Kerr. The first and a complete set of his Thai collections is housed in Botanische Staatssammlung, Munich, including unicates. He published his study on Thai plants: Die aus Siam bekannten Acanthaceen (1907), Beitrage Zur Flora Siams (1910), and Die botanischen Ergebniss miner Expedition nach Siam (1911).
He also spent time in Ceylon, Singapore and the Malay Peninsula, visiting Semangko Pass with Ridley in August 1904. He returned to Europe in January 1906 by way of Singapore. He made both botanical and ethnological collections in these countries, particularly in Negri Sembilan, making a total collection of 512 items.
He emigrated to Argentina and made botanical explorations in Patagonia from 1913-15 which resulted in numerous publications in botanical journals. He was appointed Professor of Botany at Cordoba University, Argentina in 1916 and Director of the Botanical Museum there, and he filled this office until 1946, when he resigned.
Hosseus made specimens of good quality and often with numerous duplicates. However, he concentrated on certain botanical families, such as Acanthaceae and legumes, while ignoring many woody families. The C.C. Hosseus herbarium specimens are housed at the Universidad Nacional de Cordoba Herbarium.
Harvard University Herbarium has a C.C. Hosseus collection of Pteridophytes from Argentina, Chile, China, Sri Lanka, Thailand and Uruguay. There is another plant named after Hosseus, a cactus Opuntia riojana hosseus he found in La Rioja, Argentina in 1927. In all probability Hosseus had a large network of international botanists to whom he wrote, for he had his self-addressed envelopes specially printed.