Emil Hassler

Emil Hassler (20 June 1864 – 4 November 1937) (French:, Spanish: ) was a Swiss physician, ethnographer, naturalist and botanist well known for his collections and contributions to the description of the flora and culture of Paraguay.

Early life and education Born in Aarau, Switzerland in 1864, the son of Johann Friedrich Hassler and Marie Stampfli, Hassler was educated at the Ecole des arts et métiers d'Aarau from 1880 to 1882. He studied medicine in France, completing his studies in Rio de Janeiro, Brazil. Some items from the collection were subsequently exchanged with the pre-Columbian Native American collections of the New Brunswick Museum, Canada.

Other ethnographic collections of about 10,000 items made during Hassler's expeditions between 1885 and 1895 were purchased in 1919 by the Museum of Cultures, Basel, Switzerland. In 1920, a part of these collections was gifted to the Museum of Ethnography of Geneva.

Botanical collections Hassler's botanical collections constitute the foundation of scientific knowledge of the flora of Paraguay. Collected between 1885 and 1919 by Hassler himself or under his direction, it is estimated that 90% of Paraguay's existing species are represented in his collection. Specimens were deposited in Asunción, sent to Geneva and other major global herbaria.

The collection numbers about 13,000 or about 60,000 if duplicated specimens are included. A complete catalogue of these, inclusive of other collectors' related collections from Paraguay, (Catalogus Hasslerianus, 2008-), is being published and made available online. Hassler´s about ten series of (duplicate) specimens superficially resemble exsiccatae, but the labels are partly handwritten and the numbers are collection numbers. They were distributed under various titles and subtitles, among them Dr. E. Hassler, Plantae Paraguarienses (1898-1913), Dr. E. Hassler, Plantae Paraguarienses. - 1903. Plantae a custode herbarii mei T. Rojas in Chaco septentrionali lectae and Dr. E. Hassler, Plantae Paraguarienses. - 1905. Florula Cordillerae Villaricensis. The collections formed the basis of the description of many new species, published in the work Plantae Hasslerianae in several parts between 1898 and 1907 as well as subsequent studies both by Emil Hassler and by others. These collections serve today as a basis for drafting a flora of Paraguay.

Hassler's specimens are of a high quality and include all parts necessary for identification. The attention to detail, including the formal composition of the specimen, the conservation status, etc. make these collections a very important resource for taxonomic studies of the flora of Paraguay. These qualities were demonstrated in a public exhibition at the Museum of the History of Science, Geneva in 2002.

After his death in 1937, the deposit of his botanical collection at the Geneva Botanical Garden was bequeathed to the city of Geneva. Hassler's library was purchased and is preserved in the National Library of Venezuela in Caracas.

Selected publications ( at the Internet Archive.)

( at JSTOR)