Alexander Braun
Encyclopedia
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
A decorative plant known as Braun's holly fern
(polystichum
braunii) is named after him.
Regensburg
Regensburg is a city in Bavaria, Germany, located at the confluence of the Danube and Regen rivers, at the northernmost bend in the Danube. To the east lies the Bavarian Forest. Regensburg is the capital of the Bavarian administrative region Upper Palatinate...
, Bavaria
Bavaria
Bavaria, formally the Free State of Bavaria is a state of Germany, located in the southeast of Germany. With an area of , it is the largest state by area, forming almost 20% of the total land area of Germany...
.
He studied botany in Heidelberg
Heidelberg
-Early history:Between 600,000 and 200,000 years ago, "Heidelberg Man" died at nearby Mauer. His jaw bone was discovered in 1907; with scientific dating, his remains were determined to be the earliest evidence of human life in Europe. In the 5th century BC, a Celtic fortress of refuge and place of...
, Paris
Paris
Paris is the capital and largest city in France, situated on the river Seine, in northern France, at the heart of the Île-de-France region...
and Munich
Munich
Munich The city's motto is "" . Before 2006, it was "Weltstadt mit Herz" . Its native name, , is derived from the Old High German Munichen, meaning "by the monks' place". The city's name derives from the monks of the Benedictine order who founded the city; hence the monk depicted on the city's coat...
. In 1833 he began teaching botany at the Polytechnic School of Karlsruhe
Karlsruhe
The City of Karlsruhe is a city in the southwest of Germany, in the state of Baden-Württemberg, located near the French-German border.Karlsruhe was founded in 1715 as Karlsruhe Palace, when Germany was a series of principalities and city states...
, staying there until 1846. Afterwards he was a professor of botany in Freiburg
University of Freiburg
The University of Freiburg , sometimes referred to in English as the Albert Ludwig University of Freiburg, is a public research university located in Freiburg im Breisgau, Baden-Württemberg, Germany.The university was founded in 1457 by the Habsburg dynasty as the...
(from 1846), Giessen
University of Giessen
The University of Giessen is officially called the Justus Liebig University Giessen after its most famous faculty member, Justus von Liebig, the founder of modern agricultural chemistry and inventor of artificial fertiliser.-History:The University of Gießen is among the oldest institutions of...
(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
Royal Swedish Academy of Sciences
The Royal Swedish Academy of Sciences or Kungliga Vetenskapsakademien is one of the Royal Academies of Sweden. The Academy is an independent, non-governmental scientific organization which acts to promote the sciences, primarily the natural sciences and mathematics.The Academy was founded on 2...
.
Braun is largely known for his research involving plant morphology
Plant morphology
Plant morphology or phytomorphology is the study of the physical form and external structure of plants. This is usually considered distinct from plant anatomy, which is the study of the internal structure of plants, especially at the microscopic level...
. He was a proponent of vitalism
Vitalism
Vitalism, as defined by the Merriam-Webster dictionary, is#a doctrine that the functions of a living organism are due to a vital principle distinct from biochemical reactions...
, 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
Cell theory
Cell theory refers to the idea that cells are the basic unit of structure in every living thing. Development of this theory during the mid 17th century was made possible by advances in microscopy. This theory is one of the foundations of biology...
. From his 1830s analysis of the arrangement of scales on a pine cone he was a pioneer of phyllotaxis
Phyllotaxis
In botany, phyllotaxis or phyllotaxy is the arrangement of leaves on a plant stem .- Pattern structure :...
A decorative plant known as Braun's holly fern
Fern
A fern is any one of a group of about 12,000 species of plants belonging to the botanical group known as Pteridophyta. Unlike mosses, they have xylem and phloem . They have stems, leaves, and roots like other vascular plants...
(polystichum
Polystichum
Polystichum is a genus of about 260 species of ferns with a cosmopolitan distribution. The highest diversity is in eastern Asia, with about 120 species in China alone; the region from Mexico to Brazil has nearly 100 additional species; Africa , North America , and Europe have much lower diversity...
braunii) is named after him.
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 MarsileaMarsileaMarsilea is a genus of approximately 65 species of aquatic ferns of the family Marsileaceae.These small plants are of unusual appearance and do not resemble common ferns...
and PilulariaPilulariaPilularia is a genus of unusual ferns of family Marsileaceae distributed in North Temperate regions, Ethiopian mountains, and the southern hemisphere in Australia, New Zealand, and western South America....
) - 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 ParthenogenesisParthenogenesisParthenogenesis is a form of asexual reproduction found in females, where growth and development of embryos occur without fertilization by a male...
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 QuillwortQuillwortIsoëtes, also written Isoetes and commonly known as the quillworts, is a genus of plants in the class Isoetopsida and order Isoetales. They are considered "fern allies". There are about 140-150 species, with a cosmopolitan distribution but often scarce to rare...
s) - 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 HistoryNatural HistoryNatural history is the scientific study of plants or animals.Natural History may also refer to:In science and medicine:* Natural History , Naturalis Historia, a 1st-century work by Pliny the Elder...
)