Heinrich Gustav Adolf Engler (25 March 1844 – 10 October 1930) was a German botanist. He is notable for his work on plant taxonomy and phytogeography, such as Die natürlichen Pflanzenfamilien (The Natural Plant Families), edited with Karl A. E. von Prantl. Even now, his system of plant classification, the Engler system, is still used by many herbaria and is followed by writers of many manuals and floras. It is still the only system that treats all 'plants' (in the wider sense, algae to flowering plants) in such depth.Engler published a prodigious number of taxonomic works. He used various artists to illustrate his books, notably Joseph Pohl (1864–1939), an illustrator who had served an apprenticeship as a wood-engraver. Pohl's skill drew Engler's attention, starting a collaboration of some 40 years. Pohl produced more than 33 000 drawings in 6 000 plates for Die naturlichen Pflanzenfamilien. He also illustrated Das Pflanzenreich (1900–1953), Die Pflanzenwelt Afrikas (1908–1910), Monographien afrikanischer Pflanzenfamilien (1898–1904) and the journals Engler's botanische Jahrbücher. Source: Wikipedia (en)