Orchidaceae is one of the largest, family of all plant families. There are nearly 25 thousand accepted species - about eight percent of all seed plants four times as many as there are mammal species and twice as many as there are species of birds
These impressive numbers do not take into account the huge number of new hybrids and varieties produced by orchid growers every year. Even today, hundreds of new species are described yearly, both because of revisions of long established genera whose species were not well determined, and also due to new species discovered in nature. In 2008 alone, the International Plant Names Index registered more than four hundred new descriptions.
History[edit | edit source]
The orchid family was established when Antoine Laurent de Jussieu published his Genera Plantarum, in 1789. However, even before Jussieu's classification, Linnaeus had described eight orchid genera which, nevertheless, did not form a family. At that time, all epiphytic species belonged to the genus Epidendrum. Another genus described by Linnaeus was Orchis, a Greek name refering to the shape of two small tubers that the species of this genus show, which resemble testicles. As this was the first orchid genus to be formally described, from it derived the name of the whole family
Olof Swartz recognized 25 genera in 1800. Louis Claude Richard provided us in 1817 with the descriptive terminology of the orchids.
The study of orchids has attracted several noted botanists and taxonomists through the ages. Possibly the first important figure is the English botanist John Lindley, who described thousands of species and hundreds of new genera in 1830-1840. Many genera still accepted today, however, not denying his importance, almost every orchid was new at his time.
After Lindley, two Germans taxonomist, Heinrich Gustav Reichenbach in the 1850s to 1880s and Rudolf Schlechter from 1890s to 1920s, also described thousands of species. Schlechter was responsible for the first systematic classification of orchids, used till few decades ago. The next important step was taken by George Bentham in 1881 with a new classification, recognizing subtribes for the first time.
Since Orchidaceae was proposed, research on its species has progressed without interruption. Their classification has passed through numerous revisions, and the amount of known genera they are divided has increased throughout the years, now reaching more than eight hundred.
rRNA sequencing[edit | edit source]
Phylogenetic relations are determined by the DNA sequencing from ITS nuclear ribosomal and plastid trnL intron, the trnL-F spacer, matK (gene and spacers), and rbcL regions. Clades are separated by Bayesian and Bootstrap methods.
Phylogenetic trees are based off of methods such as Neighbor joining, Maximum likelihood, and Parsimony.
Naming[edit | edit source]
Orchids are labeled with a binomial name with a generic name or genus and the epithets or the descriptive species name. The generic name is written with a initial uppercase letter, while the epithets are written with a initial lower case letter. The name is made up of words with Latin and Greek roots that describe features of the plant or in honor of an individual. For example Dracula amaliae indicates that the flowers looks like little dragons (Dracula) and that it was named after Sra. Amalia Lehmann (amaliae).
The end of the epithet provides information about the naming of the species.
|-ensis, -ense||named after a place, usually where the plant was collected.|
|-i, -ii, -ae||named after the individual who discovered the species.|
|-iana||named after the individual who brought the orchid to the attention of a botanist or in honor of an individual|
Minor differences between species such as color, shape, patterns, or morphology are indicated by the ternary name. For example Phalaenopsis lowii f. alba indicates that it is white
|Sub-species||ssp or subsp.||diversification of the primary species with geographical or ecological separation.|
|Varietas||var.||a species with a distinct appearance|
|Forma||f.||indicates a noticeable but minor deviation|
Publications[edit | edit source]
For publications, valid botanical names include an italicized botanical name and the individual who first describe the species. The individual's name can have a parenthesis around it followed by a second name. The name inside the parenthesis indicates the individual who first described the species and the second name is the individual who transferred to its currently recognized genus.
References[edit | edit source]
- Atwood JT (1986) The size of the Orchidaceae and the systematic distribution of epiphytic orchids. Selbyana 9:171-86.
- Govaerts R et al. World Checklist of Orchidaceae. The Board of Trustees of the Royal Botanic Gardens, Kew. Published on Internet access 1st March 2009.
- Yohan Pillon e Mark W.Chase. (2006). Taxonomic Exaggeration and its Effects on Orchid Conservation. Conservation Biology 21:263-5.
- Antonii Laurentii de Jussieu (1789). Genera plantarum: secundum ordines naturales disposita, juxta methodum in Horto regio parisiensi exaratam, anno M.DCC.LXXIV. Parisiis: apud viduam Herissant et Theophilum Barrois.
- Caroli Linnaei (1753). Species plantarum: exhibentes plantas rite cognitas, ad genera relatas, cum differentiis specificis, nominibus trivialibus, synonymis selectis, locis natalibus, secundum systema sexuale digestas... Holmiae: Impensis Laurentii Salvii.
- Pedáneo Dioscórides (50-70 CE). De materia medica.
- Phillip Cribb (2001) Orchidaceae. Em AM, Pridgeon, Cribb PJ, Chase MW, and Rasmussen FN eds., Genera Orchidacearum vol. 1. Oxford University Press, Oxford, UK ISBN 0198505132.