PLANT CLASSIFICATION

1
PLANT CLASSIFICATION
History Linnaeus Binomial nomenclature
system International Code of
Nomenclature Family, genus, species
Cultivars, clones, and varieties
2
Theophrastus 300BC Classified all plants as
herbs or shrubs LObel 1500s Classified by
leaf shapes Caesalpino 1583 DePlantis Proposed
classifying by structure of fruits and seeds
3
Middle ages No uniform system mostly based on
latinized descriptions. Veronica tournefortii
was Veronica floculis oblongis pedunculis
insidentibus chamaedryos folio Translation
greater speedwell with little oblong flowers
on short stalks and leaves that lie like
chamaedryos Solanum arborescens nuper inter
pergrinas allata est Translation tree-like
solanum that has been recently introduced.
4
Tournefort 1700 Institutiones Rei
Herbariae First attempt to classify based on
similar physical characteristics (genera).
Linaeus 1707. Like many of his time took name
which honored the Tilia or lime tree Trained as
a physician. Professor at Upsula Students
included Thuberg (Berberis thunbergi) Kalm
(Kalmia latifolia) Sexuality (not recognized by
Tournefort) was basis for Linaean
classification. a. All plants would have 2
names, genus and species hence the binomial b.
Classification based on floral characteristics.
Today essentially same system
5
International Code of Nomenclature Began with
DeCondolle in 1867 Finally accepted in
1930 Based on Latin, the language of
science Code Two names, genus and
species Latin, underlined or italicized Addition
al names can identify a variety or
cultivar Variety group of variants that occur
rarely, but consistently in nature.
Latinized. Cultivar Assemblage of cultivated
plants that have a special characteristic.
Maintained sex or asexually. Name not
latinized. Capitalized, preceded by cv. Or in
single
6
Plant names give information in 4 catagories a.
Descriptive of a plant part like alba, nigra,
pubescens b. Commemorative names of people,
places Kalmia, Bergenia, europa (why did I not
capitalize europa?) c. Anagrams scrambled or
misspelled names of existing words Myrica
pensylvanica (can you spell the state name?) d.
Mythological names like Dianthus,
Andromeda Taxon any unit of classification Class
ification hierarchy kingdom, division (phylum),
class, order, family, genus, species, cultivar
(variety), individual. Family This is where we
will start Group of genera with similar
characteristics Ends in -aceae Usually has a
type genus such as Rosa for Rosaceae, Acanthus
for Acanthaceae
7
Genus Group of similar species, distinguishable
from other genera by well marked
characteristics May consist of only one
species. Name is usually a noun. Species Basic
unit of classification Large number of common
characteristics that remain constant Not
watertight definition, or always
practical Dendranthema (what was it formerly
called?) Word is usually an adjective describing
the noun. Cultivar Use adopted in 1950s Man
maintained variants Group maintains identity
when prop sex or asexually
8
Clone Maintained vegetatively from a single
ancestor Hybrid Cross between 2
species Between genera rare. Heucherella designa
ted by x in front of name Group A group of
complex hybrids whose ancestry cannot be
determined, exactly. Ex Astilbe group
Simplicifolia