1. Lecture 1 Plant Systematics and Linnean taxonomy
PLANT DIVERSITY
Lecture 1
Plant Systematics and Linnean taxonomy
Lecturer: Asst. Prof. Dr. İsmail EKER

2. Common misconception FACT: Taxonomy is part of the cognitive process.
Taxonomy is very difficult and specialized
FACT: Taxonomy is part of the cognitive
process.

3. Everyone is a taxonomist!

4. What is Classification?
Classification is the arrangement of organisms into orderly groups based on their similarities
Classification is also known as taxonomy
Taxonomists are scientists that identify & name organisms

5. Why we need Latin names?
NOT UNIVERSAL!!
Common names ??

6. Problems: 1. They are too many!!! Nymphaea alba L. has: 15 in English
44 in French
105 in German
81 in Dutch
221 in Russian
…over 5000 common names worldwide!

7. Latin Names are Understood by all Taxonomists

8. 2. Many plant species do not have a common name
e.g. ~2000 spp. of Carex L. are called “sedge”

9. 3. Different plants may have the same common name
Often, two or more unrelated species are known by the same common name.
e.g. Bachelor‘s button, may thus be Tanacetum vulgare L., Knautia arvensis Coult. or Centaurea cyanus L.
Tanacetum vulgare L.
Knautia arvensis Coult.
Centaurea cyanus L.

10. 4. many common names may exist for the same species in the same language in the same or different localities.
e.g. Cornflower, bluebottle, bachelor‘s button and ragged robin all refer to the same species Centaurea cyanus L.
Centaurea cyanus L.

11. Why Latin? The selection has several advantages over modern languages:
i) Latin is a dead language and as such meanings and interpretation are not subject to changes unlike, English and other languages
ii) Latin is specific and exact in meaning
iii) grammatical sense of the word is commonly obvious
iv) Latin language employs the Roman alphabet, which fits well in the text of most languages.

12. Early Taxonomists
2350 years ago, Aristotle ( BC) was the “first taxonomist”
Aristotle divided organisms into plants & animals
Aristotle was the first to attempt to classify all the kinds of animals in his “Historia Animalium” in Latin.

13. Early Taxonomists
Aristotle’s student Theophrastus ( BC) known as the "father of botany“
His “De Historia Plantarum” is the first written literature about plants.
He first described the anatomy of plants and classified them into trees, shrubs, herbaceous perennials, and herbs.

15. Early Taxonomists
John Ray ( ), a botanist, was the first to use “Polynomial system” naming of plant in Latin
His names were very long descriptions telling everything about the plant

16. Polynomial system [before 1800]
Polynomial Nomenclature
Ranunculus calycibus, retroflexus, pedulculis falcatis, caule erecto, folis comopositis
“The buttercup with bent-back sepals, curved flower stalks, erect stems and compound leaves”

17. Carolus Linnaeus 1707 – 1778
Swedish scientist – Carl von Linne (doctor and botanist)
Called the “Father of Systematic Botany”
Established modern system of nomenclature
His binomial system of nomenclature, in which the genus and species names are used.

18. Binomial system Linnaeus, Species Plantarum (1753)
Dianthus caryophyllus L.
Abbreviation of author who discovered and described the species
Genus (pl. genera)
Always capitalized
Abbreviated on 2nd use
Specific epithet
Not capitalized
Often a descriptive adjective
neither italicized nor underlined
italicized or underlined
Binomial = 2 names
The genus comes first and is always capitalized and italicized
The specific epithet comes after the genus and is always lower case and italicized

19. Allium arsuzense Eker & Koyuncu
Photographed by Eker
Allium arsuzense Eker & Koyuncu
genus
specific epithet
Author(s)
species (taxon) name
Photographed by Eker
Allium roseum L. subsp. gulekense Koyuncu & Eker
subspecies

20. At a meeting in Paris in 1867, European & American botanists agreed to use Linnaeus’ binomial classification as the starting point for all scientific names of plants. The rules were drawn up at that meeting and these rules today have been revised at International Botanical Cogress by ICBN commitee, lastly held at Melbourn/Australia in 2011.

21. International Code of Botanical Nomenclature (ICBN)
Guidelines set by the ICBN
1. Botanical nomenclature is independent of zoological nomenclature.

22. International Code of Botanical Nomenclature (ICBN)
2. Each taxon can have only one correct name.

23. International Code of Botanical Nomenclature (ICBN)
3. Each name must be linked to a type specimen.

24. International Code of Botanical Nomenclature (ICBN)
4. Nomenclature of taxonomic groups is based on priority of publication
Polygonum aviculare L. , Species Plantarum 2:
journal name
vol.
page
date
Polygonum heterophyllum Lindman, Svensk Bot. Tidskr. 6: 690, 1912.

25. Taxonomic ranks (taxa)
(e.g. house, street, city, county, state, country, continent, planet)

26. Taxonomic ranks (taxa)
The dendrogram view of Taxonomic hierarchy

27. What is a species?
Species: a set of individuals that are closely related by descent from a common ancestor and ordinarily can reproduce with each other, but not with members of any other species.
Biological species: a group of interbreeding populations. Offspring are fertile.
“sp.” or “spp.” stands for species and never underlined or italicized
singular
plural
e.g. Allium L. sp. has a meaning of 1 Allium species
Allium L. spp. have a meaning of more than 1 Allium species

28. Species
Some members of same species look very different…

29. All these are same species!
Same species, are capable of interbreeding, but Morphologically may look very different.
Broccoli, kale, cabbage, cauliflower: members same species! Brassica oleracea L.
Broccoli: brokoli: Brassica oleracea ‘Italica Group’
Brussels sprouts: Brüksel lahanası: Brassica oleracea ‘Gemmifera Group’
Cabbage: lahana: Brassica oleracea ‘Capitata Group’
Cauliflower: karnıbahar: Brassica oleracea ‘Botrytis Group’
Kale: kara lahana: Brassica oleracea ‘Acephala Group’

30. Plant species can be divided more specifically into:
subspecies
variety
hybrid
cultivar

31. SUBSPECIFIC CATEGORIES Subspecies
A subspecies describes a group of related organisms that can interbreed and are geographically distinct from others in their species.
subspecies (abbreviated "subsp." or "ssp."; plural: "subspecies")
Photographed by Eker
Allium roseum L. subsp. roseum
Allium roseum L. subsp. gulekense Koyuncu & Eker

32. Written in lower case and italicized or underlined.
The Variety
A group of plants subordinate to the species; differing from the species in one or more inheritable characteristics.
Written in lower case and italicized or underlined.
“var.” from Latin varietas, “variety”
Cercis canadensis L. var. alba (Rehder) Bean
Cercis canadensis L.

33. Platanus occidentalis L. crossed with Platanus orientalis L.
Hybrids
two closely related but distinct species will be interbreed to form a hybrid
are often sterile and produce no seed or fruit
written in lowercase and italicized or underlined
an “x” is placed between the genus and hybrid epithet. the “x” means the plant is a hybrid.
Platanus occidentalis L. crossed with Platanus orientalis L.
Platanus x acerifolia (Aiton) Willd.

34. The Cultivar (“Cultivated variety” or horticultural variety)
In ornamental horticulture cultivar characteristics are not inheritable
Cultivar names are always capitalized and never underlined/italicized
Written in single quotations or with abbreviation of cultivar (cv.)
Example: Cercis canadensis ‘Forest Pansy’ OR
Cercis canadensis cv. Forest Pansy
A single species may have many cultivars
Juniperus horizontalis ‘Blue Chip’
Juniperus horizontalis ‘Plumosa’
Juniperus horizontalis ‘Hughes’ etc.
Plants within a species that have been selected especially for a particular characteristic and are propagated, usually asexually to continue this trait(growth habit, flower, fruitless).

35. Viburnum opulus ‘Roseum’
Viburnum opulus L.
Viburnum opulus ‘Roseum’
Viburnum opulus cv. Roseum

36. It is possible to have a cultivar of a variety
Gleditsia triacanthos inermis ‘Skyline’ Cornus florida rubra ‘Cherokee Chief’
Gleditsia triacanthos L. var. inermis ( L. ) Castigl.
Gleditsia triacanthos var. inermis ‘Skyline’