Alfred Rehder was a horticulturist and taxonomist who worked at the Arnold Arboretum of Harvard University. Rehder was a newspaper writer from Germany who was originally hired as a laborer at the Arnold Arboretum. His talents for horticultural plant taxonomy were soon recognized, however. Early in his employment he was sent to Europe to purchase books for the library at the Arboretum. When the Journal of the Arnold Arboretum was started in 1919, Rehder was co-editor, along with the Arboretum director, Charles Sprague Sargent. Rehder produced a new edition of Manual of Cultivated Trees and Shrubs and authored the Bibliography of Cultivated Trees and Shrubs and The Bradley bibliography.^[1][2] He was co-author, with Ernest Henry Wilson, of Plantae Wilsonianae and A Monograph of Azaleas.^[3] The Latin words hortus (garden plant) and cultura (culture) together form horticulture, classically defined as the culture or growing of garden plants. ... Taxonomy (from Greek ταξινομία from the words taxis = order and nomos = law) may refer to either a hierarchical classification of things, or the principles underlying the classification. ... General view of Arnold Arboretum General view of Arnold Arboretum General view of Arnold Arboretum The Arnold Arboretum of Harvard University was founded in 1872 when the President and Fellows of the then Harvard College became trustees of a portion of the estate of James Arnold (1781-1868). ... World map showing Europe Political map Europe is one of the seven traditional continents of Earth; the term continent here referring to a cultural and political distinction, rather than a physiographic one, thus leading to various perspectives about Europes precise borders. ... Charles Sprague Sargent Charles Sprague Sargent (April 21, 1841-March 22, 1927) was an American botanist. ... Ernest Henry Wilson (February 15, 1876 - October 15, 1930), better known as E. H. Wilson, was a notable plant collector who introduced a large variety of Asian plant species to the west. ...

Rehder created the first system of isothermic zones for the United States that related average winter minimum temperatures to the hardiness of specific plants. That system, along with another system developed by Vladimir Koppen, are the basis for all of the climate zone maps in use today. An isotherm is a line of equal or constant temperature on a graph, plot, or map; an isopleth of temperature. ... Wladimir Peter Köppen (September 25, 1846 in Saint Petersburg, Russia — June 22, 1940 in Graz, Austria) was a German meteorologist, climatologist and botanist. ...

References

1. ^ Howard, Richard A. (1975) The Arnold Arboretum. Botanical Society of America Plant Science Bulletin. June, 1975. Vol. 21 No. 2 [1] - URL retrieved February 26, 2006
2. ^ Antiquariaat Jan Meemelink flower books + prints - URL retrieved February 26, 2006
3. ^ History of Horticulture - Ernest Henry Wilson - URL retrieved February 26, 2006