Download Plant Nomenclature and ID - University of Alaska Fairbanks

Beginning Master Gardener Training – January 15, 2013
Plant Nomenclature and ID
Lydiae claytonii
Horticulture Extension Agent
[email protected]
Plant systematics and taxonomy
 Why classify?
 History of plant classification systems
 Some issues in plant systematics
 How to use botanical nomenclature
Why classify??
Taxonomy -- the naming of groups (taxa, singular taxon)
Systematics -- a system for classifying organisms into groups
Goals of Classification
− Simplify
− Communicate
− Predict
How to classify plants?


Functional classifications

Based on function or overall similarity

No assumption of evolutionary relationship
Functional classification systems
All cultures classify plants in ways meaningful to them
Examples of early plant classifications
 2000 BC - Indian (Ayurvedic) texts described medicinal plants
 1000-1700 AD - “Age of Herbals” in Europe
Evolutionary classification systems

Carolus Linneaus (Systemae naturae, 1732)
- defined groups based on sexual characters
- developed binomial system of plant nomenclature

Engler, Bessey, Cronquist etc. (1800 - 1980s)
- sought to define evolutionary groups of plants
- published many regional floras (still in use)
Evolutionary classification
(includes both traditional systematics and modern phylogenetics)
Reasoning
1.
Living species are related to one another by descent from common ancestors
2.
Shared character states are clues to relatedness
What about convergent evolution?
Modern solution: Phylogenetic systematics

Reconstructs relationships using lots of characters

Now, primarily uses DNA sequence data
From Nickrent et al.
Why do plant names change?
• New evolutionary data
• Rediscovery of older names
• Lumpers vs. splitters
Agropyron spicatum
Elymus spicatus
Psuedoroegneria spicata
Bluebunch wheatgrass
Usually gene trees and older taxonomy agree . . .
Monophyly (“one class”)
Named group shares an exclusive common ancestor
Primates
(humans, great apes, old world monkeys, new world monkeys, lemurs)
But sometimes named groups are not “natural”
Polyphyly and Paraphyly
Named group is not an exclusive set of closest relatives
dogs
cows
“Marine mammals”
(sea lions, sea otters, whales)
Plant nomenclature in practice
Species names (“scientific names”) are Latin binomials
Cornus florida L.
• Genus (pl. genera)
• Always capitalized
• Abbreviated on 2nd use
(C. florida)
• Specific epithet
• Authority
• Not capitalized
• Often a descriptive adjective
 Always underline or italicize
species names (genus +
specific epithet)
Why not just use common names?
Why not just use common names?
1) Only scientific names are universal, used the same world-wide;
e.g., Ipomoea -Woodbine, Morning Glory, Sweet potato
2) Common names are not consistent.
a) A taxon may have more than one common name.
b) One common name may refer to more than one taxon (e.g.,
”hemlock”).
3) Common names tell nothing about rank.
4) Many, if not most, organisms have no common name in any
language.
What is rank?
Order
-ales
Cornales
Family
-aceae
Cornaceae
Subfamily
-oideae
Cornoideae
Genus
(various)
Cornus
Species
(various)
Cornus florida
Subspecies (various)
Cornus florida ssp. urbiniana
Variety
(various)
Cornus florida var. rubra
trinomial
Rank at Family Level
Identification at family level is easily done and often
very helpful in getting on the right track.
Example Cornaceae:
• Leaves simple, lacking stipules, and variously arranged, but
commonly opposite or whorled.
• Inflorescence terminal, often composed of an umbel or
corymb of small flowers subtended by showy, petaloid bracts.
• Perianth 4 or 5-merous; sepals represented by small teeth,
fused, or entirely absent, petals small and inconspicuous.
• Stamens 4 or five. Inferior ovary of 2 or 3 fused carpels.
• Fruit a cluster of berries or drupes.
Learning binomial nomenclature
Syllabize and accent.
Some guidelines:
1. Pronounce 1 syllable for every vowel
Anemone = A-ne-mo-ne
Cardamine = Car-da-mi-ne
2. But, pronounce proper names more-or-less
normally
Carex jonesii = Carex jones-ee-ee
3. Weird double consonants are usually silent
Pseudotsuga = Su-do-(t)su-ga
Learning binomial nomenclature
Practice and review: oral and written recitation
Use mnemonic devices
• King Phillip Could Only Find Green Socks
Kingdom, Phylum, Class, Order, Family, Genus, Species
• Sedges have edges, rushes are round, grasses are
hollow straight up from the ground!
Learn the etymology or meaning
Quaking Aspen,
Populus tremuloides
(a great number; quaking)
Alaska Birch,
Betula neoalaskana
(to shine; new)
Forsythia suspensa
(named after William Forsythe; weeping)
Hybrids
One common cross is between Forsythia viridissima and Forsythia
suspensa; this group has been given the grex name Fortyshia x
intermedia, which includes most of the common.
Interspecific hybrid
Intergeneric hybrid
If you cross Platanus occidentalis,
and Platanus orientalis…
If you cross Mahonia aquifolium with
Berberis candidula…
You get Platanus x acerifolia
You get XMahoberberis aquicandidula
An unitalicized ‘x’ or ‘X’
indicating the cross
Downy brome/Cheatgrass,
Bromus tectorum
(oat-like; of roofs or houses)
Crabgrass, Digitaria sanguinalis
(resembling a finger; bloody, blood red)
Field bindweed,
Convolvulus arvensis
(to twine around;
pertaining to cultivated fields)
Japanese knotweed,
Polygonum cuspidatum
(many, swollen roots; sharp-pointed
leaves)
Common lambsquarter,
Chenopodium album
(goose-footed, white)
Fireweed,
Epilobium angustafolium
(upon lobe- position of the petals
above the ovary; narrow leaved)
Common chickweed,
Stellaria media
(Starry; divide in the middle)
Black spruce,
Picea mariana
(black in color; growing by or in the
sea )
http://plants.usda.gov
http://oregonstate.edu/dept/ldplants/
http://www.uaf.edu/museum/collec
tions/herb/library/