Taxonomy Dahlia

1 taxonomy

1.1 history

1.1.1 history
1.1.2 european introduction


1.2 classification
1.3 circumscription
1.4 subdivision

1.4.1 infrageneric subdivision

1.4.1.1 sections
1.4.1.2 species




1.5 etymology

taxonomy
history
early history

spaniards reported finding plants growing in mexico in 1525, earliest known description francisco hernández, physician philip ii, ordered visit mexico in 1570 study natural products of country . used source of food indigenous peoples, , both gathered in wild , cultivated. aztecs used them treat epilepsy, , employed long hollow stem of (dahlia imperalis) water pipes. indigenous peoples variously identified plants chichipatl (toltecs) , acocotle or cocoxochitl (aztecs). hernandez perception of aztec, spanish, through various other translations, word water cane , water pipe , water pipe flower , hollow stem flower , cane flower . these refer hollowness of plants stem.

hernandez described 2 varieties of dahlias (the pinwheel-like dahlia pinnata , huge dahlia imperialis) other medicinal plants of new spain. francisco dominguez, hidalgo gentleman accompanied hernandez on part of seven-year study, made series of drawings supplement 4 volume report. 3 of drawings showed plants flowers: 2 resembled modern bedding dahlia, , 1 resembled species dahlia merki; displayed high degree of doubleness. in 1578 manuscript, entitled nova plantarum, animalium et mineralium mexicanorum historia, sent escorial in madrid; not translated latin francisco ximenes until 1615. in 1640, francisco cesi, president of academia linei of rome, bought ximenes translation, , after annotating it, published in 1649-1651 in 2 volumes rerum medicarum novae hispaniae thesaurus seu nova plantarium, animalium et mineraliuím mexicanorum historia. original manuscripts destroyed in fire in mid-1600s.

european introduction

in 1787, french botanist nicolas-joseph thiéry de menonville, sent mexico steal cochineal insect valued scarlet dye, reported strangely beautiful flowers had seen growing in garden in oaxaca. in 1789, vicente cervantes, director of botanical garden @ mexico city, sent plant parts abbe antonio josé cavanilles, director of royal gardens of madrid. cavanilles flowered 1 plant same year, second 1 year later. in 1791 called new growths dahlia anders (andreas) dahl. first plant called dahlia pinnata after pinnate foliage; second, dahlia rosea rose-purple color. in 1796 cavanilles flowered third plant parts sent cervantes, named dahlia coccinea scarlet color.

dahlia coccinea, parent of european single dahlias (i.e., displaying single row of ligulate florets)

in 1798, cavanilles sent d. pinnata seeds parma, italy. year, marchioness of bute, wife of earl of bute, english ambassador spain, obtained few seeds cavanilles , sent them kew gardens, flowered lost after 2 3 years.

the dahlia garden @ holland house in 1907



dahlia sambucifolia

in following years madrid sent seeds berlin , dresden in germany, , turin , thiene in italy. in 1802, cavanilles sent tubers of these 3 (d. pinnata, d. rosea, d. coccinea) swiss botanist augustin pyramus de candolle @ university of montpelier in france, andre thouin @ jardin des plantes in paris , scottish botanist william aiton @ kew gardens. same year, john fraser, english nurseryman , later botanical collector czar of russia, brought d. coccinea seeds paris apothecaries gardens in england, flowered in greenhouse year later, providing botanical magazine illustration.

in 1804, new species, dahlia sambucifolia, grown @ holland house, kensington. whilst in madrid in 1804, lady holland given either dahlia seeds or tubers cavanilles. sent them england, lord holland s librarian mr buonaiuti @ holland house, raised plants. year later, buonaiuti produced 2 double flowers. plants raised in 1804 did not survive; new stock brought france in 1815. in 1824, lord holland sent wife note containing following verse:

dahlia brought our isle

your praises ever shall speak;

mid gardens sweet smile,

and in colour bright cheek.

in 1805, german naturalist alexander von humboldt sent more seeds mexico aiton in england, thouin in paris, , christoph friedrich otto, director of berlin botanical garden. more significantly, sent seeds botanist carl ludwig willdenow in germany. willdenow reclassified rapidly growing number of species, changing genus dahlia georgina; after naturalist johann gottlieb georgi. combined cavanilles species d. pinnata , d. rosea under name of georgina variabilis; d. coccinea still held separate species, renamed georgina coccinea.

classification

since 1789 when cavanilles first flowered dahlia in europe, there has been ongoing effort many growers, botanists , taxonomists, determine development of dahlia modern times. @ least 85 species have been reported: approximately 25 of these first reported wild, remainder appeared in gardens in europe. considered hybrids, results of crossing between reported species, or developed seeds sent humboldt mexico in 1805, or perhaps other undocumented seeds had found way europe. several of these discovered identical earlier reported species, greatest number new varieties. morphological variation highly pronounced in dahlia. william john cooper lawrence, hybridized hundreds of families of dahlias in 1920s, stated: have not yet seen 2 plants in families have raised not distinguished 1 other. constant reclassification of 85 reported species has resulted in considerably smaller number of distinct species, there great deal of disagreement today between systematists on classification.

in 1829, species growing in europe reclassified under all-encompassing name of d. variabilis, desf., though not accepted name. through interspecies cross of humboldt seeds , cavanilles species, 22 new species reported year, of had been classified in different ways several different taxonomists, creating considerable confusion species which.

in 1830 william smith suggested dahlia species divided 2 groups color, red-tinged , purple-tinged. in investigating idea lawrence determined exception of d. variabilis, dahlia species may assigned 1 of 2 groups flower-colour: group (ivory-magenta) or group ii (yellow-orange-scarlet).

circumscription

the genus dahlia situated in asteroideae subfamily of asteraceae, in coreopsideae tribe. within tribe second largest genus, after coreopsis, , appears defined clade within coreopsideae.

subdivision
infrageneric subdivision

sherff (1955), in first modern taxonomy described 3 sections 18 species recognised, pseudodendron, epiphytum , dahlia. 1969 sørensen recognised 29 species , 4 sections splitting off entemophyllon section dahlia. contrast giannasi (1975) using phytochemical analysis based on flavonoids, reduced genus 2 sections, entemophyllon , dahlia, latter having 3 subsections, pseudodendron, dahlia, , merckii. sørensen issued further revision in 1980, incorporating subsection merckii in original section dahlia. when described 2 new species in 1980s (dahlia tubulata , d. congestifolia), placed them within existing sections. further species, dahlia sorensenii added hansen , hjerting in (1996). @ same time demonstrated dahlia pinnata should more designated d. x pinnata. d. x pinnata shown variant of d. sorensenii had acquired hybrid qualities before introduced europe in sixteenth century , formally named cavanilles. original wild d. pinnata presumed extinct. further species continue described, saar (2003) describing 35 species. separation of sections on morphological, cytologal , biocemical criteria has not been entirely satisfactory.

to date these sectional divisions have not been supported phylogenetically, demonstrate section entemophyllon distinct sectional clade. other major grouping core dahlia clade (cdc), includes of section dahlia. remainder of species occupy has been described variable root clade (vrc) includes small section pseudodendron monotypic section epiphytum , number of species within section dahlia. outside of these 3 clades lie d. tubulata , d. merckii polytomy.

horticulturally sections retain usage, section pseudodendron being referred tree dahlias , epiphytum vine dahlia . remaining 2 herbaceous sections being distinguished pinnules, opposing (dahlia) or alternating (entemophyllon).

sections

sections (including chromosome numbers), geographical distribution;

epiphytum sherff (2n = 32)

10 m tall climber aerial roots 5 cm thick , more 20 m long; pinnules opposite
1 species, d. macdougallii sherff
mexico: oaxaca


entemophyllon p. d. sorensen (2n = 34)

6 species
mexico: hidalgo, nuevo león, tamaulipas, querétaro, durango, san luis potosí


pseudodendron p. d. sorensen (2n = 32)

3 species + d. excelsa of uncertain identity
mexico: chiapas, guerrero, jalisco, michoacan, oaxaca, , costa rica, el salvador, guatemala & colombia


dahlia (2n = 32, 36 or 64)

24 species
mexico: distrito federal, guerrero, hidalgo, morelos, nuevo león, puebla, san luis potosí, tamaulipas, veracruz, oaxaca, puebla, chiapas, méxico, huehuetenango, chihuahua, durango, michoacan & guatemala

only pseudodendron (d. imperialis) , dahlia (d. australis, d. coccinea) occur outside mexico.

species

there 42 accepted species in dahlia genus, new species continue described.

etymology

the naming of plant has long been subject of confusion. many sources state name dahlia bestowed pioneering swedish botanist , taxonomist carl linnaeus honor late student, anders dahl, author of observationes botanicae. however, linnaeus died in 1778, more eleven years before plant introduced europe in 1789, while agreed plant named in 1791 in honor of dahl, had died 2 years before, linnaeus not have been 1 did so. abbe antonio jose cavanilles, director of royal gardens of madrid, should credited attempt scientifically define genus, since not received first specimens mexico in 1789, named first 3 species flowered cuttings.

regardless of bestowed it, name not established. in 1805, german botanist carl ludwig willdenow, asserting genus dahlia thunb. (published year after cavanilles s genus , considered synonym of trichocladus) more accepted, changed plants genus dahlia georgina; after german-born naturalist johann gottlieb georgi, professor @ imperial academy of sciences of st. petersburg, russia. reclassified , renamed first 3 species grown, , identified, cavanilles. not until 1810, in published article, officially adopted cavanilles original designation of dahlia. however, name georgina still persisted in germany next few decades.

dahl homophone of swedish word dal , or valley ; although not true translation, plant referred valley flower .