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Whisk Ferns
''Psilotum'' is a genus of fern-like vascular plants. It is one of two Genus, genera in the Family (biology), family Psilotaceae commonly known as whisk ferns, the other being ''Tmesipteris''. Plants in these two genera were once thought to be descended from the earliest surviving vascular plants, but more recent phylogenies place them as basal ferns, as a sister group to Ophioglossales. They lack true roots and Leaf, leaves are very reduced, the stems being the organs containing photosynthetic and conducting tissue. There are only two species in ''Psilotum'' and a hybrid between the two. They differ from those in ''Tmesipteris'' in having stems with many branches and a Sporangium#Synangium, synangium with three lobes rather than two. Description and life cycle Whisk ferns in the genus ''Psilotum'' lack true roots but are anchored by creeping rhizomes. The stems have many branches with paired enations, which look like small leaves but have no vascular tissue. Above these enation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olof Swartz
Olof Peter Swartz (21 September 1760 – 19 September 1818) was a Swedish botanist and taxonomist. He is best known for his taxonomic work and studies into pteridophytes. Biography Olof Swartz attended the University of Uppsala where he studied under Carl Linnaeus the Younger (1741–1783) and received his doctorate in 1781. He first traveled in 1780 to Lapland in the company of several other botanists. In 1783 he sailed for North America and the West Indies, primarily in the area of Jamaica and Hispaniola, to collect botanical specimens. His botanical collection, of an impressive 6000 specimens, is now held by the Swedish Museum of Natural History, as part of the Regnellian herbarium. By 1786 he left for London to prepare his collection. There he met naturalist Joseph Banks (1743–1820), who was impressed with his knowledge of Botany. He was offered a position with the British East India Company as a travelling physician, but turned it down, and returned to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |