Alexander Braun

Alexander Carl Heinrich Braun (May 10, 1805 – March 29, 1877) was a German botanist from Regensburg, Bavaria.

He studied botany in Heidelberg, Paris and Munich. In 1833 he began teaching botany at the Polytechnic School of Karlsruhe, staying there until 1846. Afterwards he was a professor of botany in Freiburg (from 1846), Giessen (from 1850) and at the University of Berlin (1851), where he remained until 1877. While in Berlin, he was also director of the Berlin Botanical Garden. In 1852, he was elected a foreign member of the Royal Swedish Academy of Sciences.

Braun is largely known for his research involving plant morphology. He was a proponent of vitalism, a popular 19th century speculative theory which stated that a regulative force exists within living matter in order to maintain functionality. Despite these beliefs, Braun made important contributions in the field of cell theory. From his 1830s analysis of the arrangement of scales on a pine cone he was a pioneer of phyllotaxis^[1]

A decorative plant known as Braun's holly fern (polystichum braunii) is named after him.^[2]

Written works

• 1831: Untersuchung über die Ordnung der Schuppen an den Tannenzapfen (Investigation on the Order of Shapes in Pine Cones)
• 1842: Nachträgliche Mitteilungen über die Gattungen Marsilia und Pilularia (Subsequent Messages on the Genera Marsilea and Pilularia)
• 1850: Betrachtungen über die Erscheinung der Verjüngung in der Natur, insbesondere in der Lebens- und Bildungsgeschichte der Pflanze (Reflections on the Phenomenon of Rejuvenation in Nature, particularly in Life and Developmental History of the Plant)
• 1852: Über die Richtungsverhältnisse der Saftströme in den Zellen der Characeen
• 1853: Das Individuum der Pflanze in seinem Verhältnis zur Spezies etc. (The Individual Plant in its Relation to Species, etc.)
• 1854: Über den schiefen Verlauf der Holzfaser und die dadurch bedingte Drehung der Stämme
• 1854: Über einige neue und weniger bekannte Krankheiten der Pflanzen, welche durch Pilze erzeugt werden (On New and Lesser-known Diseases of Plants produced by Fungi)
• 1854: Das Individuum der Species in seinem Verhältnis zur Pflanze (The Individual of the Species in its Relationship to the Plant)
• 1855: Algarum unicellularium genera nova et minus cognita
• 1856: Über Chytridium, eine Gattung einzelliger Schmarotzergewächse auf Algen und Infusorien
• 1857: Über Parthenogenesis bei Pflanzen (On Parthenogenesis in Plants)
• 1860: Über Polyembryonie und Keimung von Caelebogyne
• 1862: Über die Bedeutung der Morphologie (On the Importance of Morphology)
• 1862: Zwei deutsche Isoetesarten (Two German Isoëtes Species)
• 1863: Über Isoetes (On Quillworts)
• 1865: Beitrag zur Kenntnis der Gattung Selaginella (Contribution to the Knowledge of the Genus Selaginella)
• 1867: Die Characeen Afrikas (The African Characeae)
• 1867: Conspectus systematicus Characearum europaearum
• 1870: Neuere Untersuchungen über die Gattungen Marsilia und Pilularia (Recent Studies on the Genera Marsilea and Pilularia)
• 1872: Über die Bedeutung der Entwicklung in der Naturgeschichte (On the Importance of Development in Natural History)

References

• This article is based on a translation of the equivalent article from the German Wikipedia.