Horticulture Principles and Practices

herbs), Subdivision (monocots versus dicots), Class (fruit types), Subclass (flower & leaf
characters). Although criteria is different today, this was the beginning of a hierarchal
scheme of classification, and regarded as the beginning of natural classification. Pierre
Magnol (1638–1715) provided the first concept of modern families in his Prodromus
historiae generalis.
Joseph Pitton de Tournefort (1656–1708) was a French botanists known as the
“genus man”. He describe 700 genera with 9000 species in his Institutione rei herbariae.
The genus was the fundamental category of classification, base upon floral characters.
Genera are artificial in modern concepts, having placed many non-related species
together in the same genus. Genera were grouped into classes. Plant names included a
large number of binominals, but inconsistently used along with polynominals.
THE LINNEAN ERA
Carl von Linné = Linnaeus (1707–1778) was the Swedish son of a Lutheran pastor
and gardener. He studied pre-med under Professor Rudbeck, the physician to George
Clifford, a wealthy banker interested in botany and horticulture. Linnaeus practice
medicine while pursuing his true love with several plant expeditions. He lectured at
the prestigious University of Upsalla, and was awarded a professorship in 1741. He
restored the university’s botanical garden, made plant expeditions, and inspi
Included were Carl Thunberg (Japan), Daniel Solander (Cook’s 1st world voyage),
Andeds Sparrman (Cook’s 2nd world voyage), and Pehr Kalm (NE American colonies).
Linnaeus published 148 books, several financed by Clifford. His religious background
influence his taxonomic philosophy, that the study of nature would reveal the Divine
Order of God's creation, and it was the naturalist's task to construct a "natural classification"
that would reveal this Order in the universe. In Species plantarum, his classification
was based entirely upon the number and arrangement of the reproductive organs.
A plant's class was determined by its stamens and its order by its pistils. This
classification was controversial in its day, produced some unnatural grouping, but was
easy to learn and use. A focus of prior authors was to replace past nomenclature with
your own. Linnaeus won this competition.
Linnaeus made several taxonomic contributions with Species plantarum published
on May 1, 1753. His classification scheme provided the first set of taxonomic keys, as
one could identify unknown plant by counting the number of reproductive organs and
noting their arrangement. He was the first to consistently use binominals, following
Bauhin’s concept of genus and species. He was the first to recognize varieties (by using
Greek letters), natural populations within a species that bear a few distinctive traits different
from typical species members. He segregated the name from the diagnosis (descriptive
phrase of key character traits). For each species, Linnaeus included synonymy
and abbreviated references to prior publications. He included the species nativity region.
Using Latin, instead of his native Swedish, made his book immediately usable throughout
Europe. Many botanists began adopting Linnaeus’ nomenclature as the classification
scheme was easy to use, and binominal names easier to remember. For his contributions,
he is often called the Father of Taxonomy.
Michael Adanson (1727–1806) was a French naturalist of tropical Africa who rejected
Linnaeus’ philosophy. He rejected the idea of character weighing, that some characters
such as reproductive organs were more valuable than others, such as vegetative
traits. Taxonomists generally did not accept the Adansonian philosophy. However, recently
numerical taxonomists were advocates of Adanson in preparing databases for
computers (non biased by man) to delineate relationships. But, unacceptable results have
led currently to character weighing by taxonomists entering data.
Jean Bergeret (1751–1813) was a French botanist who proposed a 15-letter uninomial
system. Each letter would express a descriptive character. Thus Belladona
(currently Atropa belladona) would be Ieglyabiajisbey. This was regarded as the worst
38 Chapter 2 Classifying and Naming Horticultural Plants