Thorne system

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A system of plant taxonomy, the Thorne system of plant classification was devised by the American botanist Robert F. Thorne (1920–2015) in 1968, [1] and he continued to issue revisions over many years (1968–2007). [1] [2] [3] [4] [5] [6] [7] [8]


Some versions of the system are available online. The Bioinformatics Working Group Center for the Study of Digital Libraries at Texas A&M University lists the March 1999 version [9] (and other classification systems). [10] James Reveal's course lecture notes (1999) also gives an account of the Thorne system at that time, with an extensive listing of synonyms, both nomenclatural and taxonomic, for each name in the system [11] together with several other classification systems. [12]

For a discussion of the various suffixes used for superorders (-floraevs.-anae), see Brummitt 1992, [13] and Thorne 1992. [5] In this latter paper, Thorne sets out his reasons for abandoning -florae for -anae, following contemporary practice.

1968 System



1992 System

The 1992 system lists 69 orders and 440 families




2007 System

The 2007 system lists 12 subclasses, 35 superorders, 87 orders, 40 suborders, and 472 families. It uses the suffixes given in the following example.

Class Magnoliopsida ("Angiospermae") - 12 subclasses

Subclasses (12)

Note: Monocotyledons are represented here by 3 separate subclasses 3–5 [14]

Related Research Articles

Liliales Order of monocot flowering plants, including lilies

Liliales is an order of monocotyledonous flowering plants in the Angiosperm Phylogeny Group and Angiosperm Phylogeny Web system, within the lilioid monocots. This order of necessity includes the family Liliaceae. The APG III system (2009) places this order in the monocot clade. In APG III, the family Luzuriagaceae is combined with the family Alstroemeriaceae and the family Petermanniaceae is recognized. Both the order Lililiales and the family Liliaceae have had a widely disputed history, with the circumscription varying greatly from one taxonomist to another. Previous members of this order, which at one stage included most monocots with conspicuous tepals and lacking starch in the endosperm are now distributed over three orders, Liliales, Dioscoreales and Asparagales, using predominantly molecular phylogenetics. The newly delimited Liliales is monophyletic, with ten families. Well known plants from the order include Lilium (lily), tulip, the North American wildflower Trillium, and greenbrier.

Magnoliales Basal order of flowering plants

The Magnoliales are an order of flowering plants.

Dicotyledon Historical grouping of flowering plants

The dicotyledons, also known as dicots, are one of the two groups into which all the flowering plants or angiosperms were formerly divided. The name refers to one of the typical characteristics of the group, namely that the seed has two embryonic leaves or cotyledons. There are around 200,000 species within this group. The other group of flowering plants were called monocotyledons or monocots, typically having one cotyledon. Historically, these two groups formed the two divisions of the flowering plants.


The Nymphaeales are an order of flowering plants, consisting of three families of aquatic plants, the Hydatellaceae, the Cabombaceae, and the Nymphaeaceae. It is one of the three orders of basal angiosperms, an early-diverging grade of flowering plants. At least 10 morphological characters unite the Nymphaeales. Molecular synapomorphies are also known.


Magnoliopsida is a valid botanical name for a class of flowering plants. By definition the class will include the family Magnoliaceae, but its circumscription can otherwise vary, being more inclusive or less inclusive depending upon the classification system being discussed.

LiliopsidaBatsch is a botanical name for the class containing the family Liliaceae. It is considered synonymous with the name monocotyledon. Publication of the name is credited to Scopoli : see author citation (botany). This name is formed by replacing the termination -aceae in the name Liliaceae by the termination -opsida.


Smilacaceae, the greenbrier family, is a family of flowering plants. Up to some decades ago the genera now included in family Smilacaceae were often assigned to a more broadly defined family Liliaceae, but for the past twenty to thirty years most botanists have accepted Smilacaceae as a distinct family. It is considered that the two families diverged around 55 million years ago during the Early Paleogene possibly near the boundary between Paleocene and Eocene. One characteristic that distinguishes Smilacaceae from most of the other members of the Liliaceae-like Liliales is that it has true vessels in its conducting tissue. Another is that the veins of the leaves, between major veins, are reticulate (net-shaped), rather than parallel as in most monocots.

The Cronquist system is a taxonomic classification system of flowering plants. It was developed by Arthur Cronquist in a series of monographs and texts, including The Evolution and Classification of Flowering Plants and An Integrated System of Classification of Flowering Plants (1981).

Proteales Order of eudicot flowering plants

Proteales is the botanical name of an order of flowering plants consisting of three families. The Proteales have been recognized by almost all taxonomists.


Illiciales is an order of flowering plants that is not recognized by the current most widely used system of plant classification, the Angiosperm Phylogeny Group's APG III system. The order was comprised differently in various systems of plant taxonomy, but is composed of 2-4 families of shrubs, trees, and lianas native to Australasia, south eastern Asia, and the southeastern United States. The families all contain species with essential oils, and flowers with a perianth with bracts, sepals, and petals incompletely distinguished from each other and not arranged in definite whorls. The families of the order had been variably placed in other orders in different taxonomies.

<i>Austrobaileya</i> Species of plant

Austrobaileya is the sole genus consisting of a single species that constitutes the entire flowering plant family Austrobaileyaceae. The species Austrobaileya scandens grows naturally only in the Wet Tropics rainforests of northeastern Queensland, Australia.


Nelumbonaceae is a family of aquatic flowering plants. Nelumbo is the sole extant genus, containing Nelumbo lutea, native to North America, and Nelumbo nucifera, widespread in Asia. At least four other genera, Nelumbites, Exnelumbites, Paleonelumbo, and Nelumbago, are known from fossils.


Trimeniaceae is a family of flowering plants recognized by most taxonomists, at least for the past several decades. It is a small family of one genus, Trimenia, with eight known species of woody plants, bearing essential oils. The family is subtropical to tropical and found in Southeast Asia, eastern Australia and on several Pacific Islands.

One of the modern systems of plant taxonomy, the Dahlgren system was published by monocot specialist Rolf Dahlgren in 1975 and revised in 1977, and 1980. However, he is best known for his two treatises on monocotyledons in 1982 and revised in 1985. His wife Gertrud Dahlgren continued the work after his death.

A system of plant taxonomy, the Takhtajan system of plant classification was published by Armen Takhtajan, in several versions from the 1950s onwards. It is usually compared to the Cronquist system. It admits paraphyletic groups.

Liliidae is a botanical name at the rank of subclass. Circumscription of the subclass will vary with the taxonomic system being used ; the only requirement being that it includes the family Liliaceae.


Lilianae is a botanical name for a superorder of flowering plants. Such a superorder of necessity includes the type family Liliaceae. Terminations at the rank of superorder are not standardized by the International Code of Nomenclature for algae, fungi, and plants (ICN), although the suffix -anae has been proposed.


Magnoliids are a group of flowering plants. Until recently, the group included about 9,000 species, including magnolias, nutmeg, bay laurel, cinnamon, avocado, black pepper, tulip tree and many others. That group is characterized by trimerous flowers, pollen with one pore, and usually branching-veined leaves.

Robert Folger Thorne American botanist

Dr. Robert F. Thorne was an American botanist. He was Taxonomist and Curator Emeritus at Rancho Santa Ana Botanic Garden and Professor Emeritus at Claremont Graduate University in Claremont, California. His research has contributed to the understanding of the evolution of flowering plants.

Magnoliidae <i>sensu</i> Chase & Reveal

Magnoliidae is a subclass of Equisetopsida in the sense used by Mark W. Chase and James L. Reveal in their 2009 article "A phylogenetic classification of the land plants to accompany APG III." This subclass comprises the angiosperms or flowering plants.


  1. 1 2 Thorne 1968.
  2. Thorne 1976.
  3. Thorne 1977.
  4. Thorne 1983.
  5. 1 2 Thorne 1992a.
  6. Thorne 1992b.
  7. Reveal 1999a.
  8. Thorne & Reveal 2007.
  9. Robert F. Thorne. 1992. Classification and Geography of Flowering Plants. Botanical Review 58: 225-348 as updated December, 1992 and March, 1999. Source for March 1999 in Reveal (1999a)
  10. Texas A&M Flowering Plant Gateway
  11. Reveal 1999b.
  12. Reveal 1999c.
  13. Brummitt 1992, pp. 770–776.
  14. Singh 2019, p. 260.


Works by Thorne