Olaf Hagerup (29 September 1889 – 2 March 1961) was a Danish

botanist Botany, also called , plant biology or phytology, is the science of plant life and a branch of biology. A botanist, plant scientist or phytologist is a scientist who specialises in this field. The term "botany" comes from the Ancient Greek wo ...

. He studied botany at the University of Copenhagen from 1911 under the professors Eugenius Warming, Christen C. Raunkiær, L. Kolderup Rosenvinge og W. Johannsen. He took his Ph.D. from the same university in 1930. From 1934 to 1960, he was superintendent at the

Botanical Museum The Harvard University Herbaria and Botanical Museum are institutions located on the grounds of Harvard University at 22 Divinity Avenue, Cambridge, Massachusetts. The Botanical Museum is one of three which comprise the Harvard Museum of Natural ...

of the University of Copenhagen. Hagerup’s scientific works concern evolution, polyploidy and pollination, among other things. He showed that the tetraploid

Empetrum ''Empetrum'' is a genus of three species of dwarf evergreen shrubs in the heath family Ericaceae. They are commonly known as crowberries and bear edible fruit. They are commonly found in the northern hemisphere, from temperate to subarctic clima ...

hermaphroditum is a separate species from the

diploid Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respectively ...

nigrum. He thereby initiated the use of chromosome numbers in

systematic Systematic may refer to: Science * Short for systematic error * Systematic fault * Systematic bias, errors that are not determined by chance but are introduced by an inaccuracy (involving either the observation or measurement process) inheren ...

botany, a field later known as

cytotaxonomy Cytotaxonomy is the classification of organisms using comparative studies of chromosomes during mitosis. Description Cytotaxonomy is a branch of taxonomy that uses the characteristics of cellular structures to classify organisms. In cytotaxonomy, ...

. He put forward the hypothesis that the

ploidy Ploidy () is the number of complete sets of chromosomes in a cell (biology), cell, and hence the number of possible alleles for Autosome, autosomal and Pseudoautosomal region, pseudoautosomal genes. Sets of chromosomes refer to the number of mat ...

level is an important factor in the distribution and ecology of plant species. In contrast, another of his scientific ideas has been disproven by later modern research – the idea of a direct ancestry of the ''centrosperms'' (approximately equal to Caryophyllales) from the gymnospermous Gnetophyta and, hence, two separate evolutionary lineages within the flowering plants. Many of Hagerup’s studies were concerned with plant species of the Ericaceae,

Empetraceae The Ericaceae are a family of flowering plants, commonly known as the heath or heather family, found most commonly in acidic and infertile growing conditions. The family is large, with c.4250 known species spread across 124 genera, making it th ...

and related families, or ’’Bicornes’’ as they were known in the Wettstein system. The cranberry ''Oxycoccus hagerupii'' ( Ericaceae) was named to his honour by Á. & D. Löve (later transferred to Vaccinium by

Hannu Ahokas Hannu, Hennu or Henenu was an Egyptian noble, serving as ''m-r-pr'' "majordomo" to Mentuhotep III in the 20th century BC. He reportedly re-opened the trade routes to Punt and Libya for the Middle Kingdom of Egypt. He was buried in a tomb in Dei ...

as Vaccinium hagerupii.

Scientific works

*Hagerup, O. (1915) The structure and biology of arctic flowering plants. 10. Caprifoliaceae. Linnaea borealis L. Meddelelser om Grønland 37: 151-164. *Hagerup, O. (1922) Empetrum nigrum L. (On Empetrum nigrum L. A study of natural history). Botanisk Tidsskrift 37 (4): 253-304. *Hagerup, O. (1922) Erica cinerea L. (On ”Lobelia diagram” by Erica cinerea L.) Botanisk Tidsskrift 38: 137-140. *Hagerup, O. (1926)

Koenigia islandica ''Koenigia islandica'' is a species of annual flowering plant in the buckwheat family, Polygonaceae and is the type species of the genus ''Koenigia''. It is a very small plant and is found growing on wet gravel and scree in arctic tundra and alpi ...

L. (The anatomy and development of sexual structures in

L.) Meddelelser om Grønland 58 (3): 197-204. *Hagerup, O. (1927) Empetrum hermaphroditum (Lge) Hagerup, a new tetraploid, bisexual species.

Dansk Botanisk Arkiv ''Dansk Botanisk Arkiv'' was a Danish scientific journal or monograph series concerning botany, issued by the Danish Botanical Society. It was published from 1913 to 1980. Articles were written in Danish, German, English and French. The synonym R ...

5 (2): 1–17. *Hagerup, O. (1928) Morphological and cytological studies of Bicornes.

6 (1): 1-27. *Hagerup, O. (1928) (

Aeschynomene aspera ''Aeschynomene aspera'' is a species of flowering plant in the family Fabaceae. It is also known by the names sola (''Odia'' ସୋଲ), shola (''Bengali'' শোলা) sola pith plant, pith plant, laugauni (Hindi) ponguchedi (Malayalam) or Net ...

L.) (A hydrophilic legume (

L.) with bacterial nodules on the stem).

5 (14): 1-9. *Hagerup, O. (1929) Raunkiær Tombouctou. , Kongelige Danske Videnskabernes Selskab 9 (4): 1-116. *Hagerup, O. (1930) .

6 (4): 1-20. *Hagerup, O. (1930) . Doctoral dissertation, University of Copenhagen.

6 (8): 1-104. *Hagerup, O. (1932) .

Hereditas ''Hereditas'' (not to be confused with another journal called ''Heredity'') is a scientific journal concerning genetics. It has been published since 1920 by Mendelska sällskapet i Lund (Mendelian Society of Lund). In its long history it has publi ...

16: 19-40. *Hagerup, O. (1932) On Pollination in the extremely hot air at

Timbuctu Timbuktu ( ; french: Tombouctou; Koyra Chiini: ); tmh, label=Tuareg, script=Tfng, ⵜⵏⴱⴾⵜ, Tin Buqt a city in Mali, situated north of the Niger River. The town is the capital of the Tombouctou Region, one of the eight administrative ...

8 (1): 1-20. *Hagerup, O. (1933) Studies on polyploid ecotypes in Vaccinium uliginosum L.

18 (1-2): 122-128. *Hagerup, O. (1933) . , Kongelige Danske Videnskabernes Selskab 10 (7). *Hagerup, O. (1934) . , Kongelige Danske Videnskabernes Selskab 11 (4): 1-83. *Hagerup, O. (1935) . , Kongelige Danske Videnskabernes Selskab 11 (9): 1-88. *Hagerup, O. (1936) . , Kongelige Danske Videnskabernes Selskab 13 (6): 1-60. *Hagerup, O. (1938) On the origin of some Angiosperms through the Gnetales and the Coniferae. III. The gynaecium of Salix cinerea. , Kongelige Danske Videnskabernes Selskab 14 (4): 1-34. *Hagerup, O. (1938) A peculiar asymmetrical mitosis in the microspore of Orchis.

24: 94-96. *Hagerup, O. (1938) Studies on the significance of polyploidy. II. Orchis.

24: 258-264. *Hagerup, O. (1939) On the origin of some Angiosperms through the Gnetales and the Coniferae. IV. The gynaecium of Personatae. , Kongelige Danske Videnskabernes Selskab 15 (2): 1-39. *Hagerup, O. (1939) Studies on the significance of polyploidy. III. Deschampsia and Aira.

25: 185-192. *Hagerup, O. (1940) Studies on the significance of polyploidy. IV. Oxycoccus.

26: 399-410. *Hagerup, O. (1941) . Planta 32: 6-14. *Hagerup, O. (1941) Liparis og Malaxis. (Pollination in Liparis and Malaxis). Botanisk Tidsskrift 45: 396-402. *Hagerup, O. (1942) The morphology and biology of the Corylus-fruit. , Kongelige Danske Videnskabernes Selskab 17 (6): 1-42. *Hagerup, O. (1942) . (Ant pollination). Botanisk Tidsskrift 46: 116-123. *Hagerup, O. (1944) Notes on some boreal polyploids.

30: 152-160. *Hagerup, O. (1944) On fertilization, polyploidy and haploidy in Orchis maculatus L. sens. lat.

11 (5): 1-26. *Hagerup, O. (1944) . (Cytology of the basidia by Tremellodon gelatinosum (Scop.) Pers). Friesia 3: 46-51. *Hagerup, O. (1945) Facultative parthenogenesis and haploidy in Epipactis latifolia. , Kongelige Danske Videnskabernes Selskab 19 (11): 1-14. *Hagerup, O. (1945) ( Limacella) lenticularis Lasch (Cytology of the basidia by Lepiota ( Limacella) lenticularis Lasch). Friesia 3: 96-100. *Hagerup, O. (1946) Studies on the

. , Kongelige Danske Videnskabernes Selskab 20 (5): 1-49. *Hagerup, O. (1947) The spontaneous formation of

haploid Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respectively ...

, polyploid, and aneuploid

embryo An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male spe ...

s in some orchids. , Kongelige Danske Videnskabernes Selskab 20 (9): 1-22. *Hagerup, O. (1950) Thrips pollination in Calluna. , Kongelige Danske Videnskabernes Selskab 18 (4): 1-16. *Hagerup, O. (1950) Rain- pollination. , Kongelige Danske Videnskabernes Selskab 18 (5): 1-18. *Hagerup, O. (1951) Pollination in the Faroes - in spite of rain and poverty in insects. , Kongelige Danske Videnskabernes Selskab 18 (15): 1-48. *Hagerup, O. (1952) Bud autogamy in some northern orchids. Phytomorphology 2: 51-61. *Hagerup, O. (1952) The morphology and biology of some primitive orchid flowers. Phytomorphology 2: 134-138. *Hagerup, O. (1953) Chamaeorchis. Blyttia 11: 1-5.
Hagerup, Else & Olaf (1953) Thrips pollination of ''Erica tetralix''. New Phytologist 52 (1): 1-7
*Hagerup, O. (1953) The morphology and systematics of the leaves in Ericales. Phytomorphology 3: 459-464. *Hagerup, O. (1953) Thrips-pollination in Hypochoeris radicata. 3: 55-58. *Hagerup, O. (1954) Autogamy in some drooping Bicornes flowers. Botanisk Tidsskrift 51: 103-116.
Hagerup, O. (1957) Wind autogamy in ''Arbutus''. Bulletin du Jardin botanique de l'État a Bruxelles 27 (1): 41-47.
*Hagerup, Olaf & Petersson, Vagn (1956–1960) ''Botanical Atlas''. Copenhagen: Munksgaard. **Vol. I: Angiosperms, 550 p. **Vol. II:

Moss Mosses are small, non-vascular flowerless plants in the taxonomic division Bryophyta (, ) '' sensu stricto''. Bryophyta (''sensu lato'', Schimp. 1879) may also refer to the parent group bryophytes, which comprise liverworts, mosses, and hor ...

es, Ferns, Horsetails, Clubmosses,

Conifer Conifers are a group of conifer cone, cone-bearing Spermatophyte, seed plants, a subset of gymnosperms. Scientifically, they make up the phylum, division Pinophyta (), also known as Coniferophyta () or Coniferae. The division contains a single ...

s, Evolution. 299 p.

References

{{DEFAULTSORT:Hagerup, Olaf 20th-century Danish botanists Botanists active in Africa Academic staff of the University of Copenhagen University of Copenhagen alumni 1889 births 1961 deaths