Vascular Plant Diversity
Ref. No. Families No. Genera No. species
Bailey’s Cyclopedia,
1930's 223 20,602
Hortus Third, 1976 281 3,301 20,397
New RHS, 1992 3,983
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Rehder’s Manual of Trees
and Shrubs, 1940 113 486 2,550
Bailey’s Manual of
Cultivated Plants, 1949 194 1,523 5,347
About 50 % of vascular plants are woody, and 50 % are herbaceous.
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Gray’s Manual of Botany
for northeastern U.S., 1950 168 1,133 5,523
Voss, Michigan Flora,
1972, 1985, 1996 2,525
About 50 % of the species in northeastern U.S.(includes midwest) are found in Michigan.
Specifically, aboout 50 % of the grasses, and 70 % of the orchids are found in Michigan.
Michigan has 80 genera of woody plants that are native or introduced.
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Brummitt, Vascular Plant
Families and Genera of
the World, 1992 511 13,888
About 14,000 genera are native in the world today.
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Mabberley’s Plant Book has 20,000 names, including synonyms, families, and
some common names. 1997 (2nd ed.)
About 45 genera have over 500 species.
Number of species by Taxonomic Group
Taxonomic Group No. species No. species No. species No. species
in World in N. America in N.E. U.S. in Michigan
A. Vertebrates (animals with backbones)
Fish 25,000 4,000 200
Amphibians 2,500 180 20
Reptiles 6,000 430 30
Birds 8,600 1,420 200
Mammals 4,200 3,600 100
B. Vascular Plants
Division Psilotophyta 12
1 family, 2 Genera
Division Lycopodiophyta 1200 26 15
3 Families, 5-8 Genera
Division Equisetophyta 15 11 11
Equisetum, 1 Family, 1 Genus
Division Polypodiophyta 12,000 86 54
Ferns, 36 famililes, 220 Genera
Division Pinophyta 830 30 12
Gymnosperms, 12-15 Families, 80 Genera
Division Magnoliophyta 220,000
Flowering Plants, 383 Families,12,300 Genera
Class Liliopsida 50,000 1,415 710
Monocots, 65 Families, 2,700 Genera
Class Magnoliopsida 170,000 3,955 1743
Dicots, 318 Families, 9,600 Genera
On the Sizes of Floras
Flora is a botanical word for plants growing in a particular area; or a descriptive,
systematic list of plants of a specific region or period in time. The period in time refers
to its use for fossil floras.
The zoological or animal equivalent of Flora is Fauna.
The following sizes are from DeWolf, G.P. Jr. 1964. “On the sizes of floras.” Taxon 13 (5):
149-153.
Flora of North America (north of Mexico) 12,000 species
South and Central America 30,000 species
Africa 40,000 species
Europe 10,000 species
Asia (north of Himalayas) 13,000 species
Asia (south of Himalayas) 25,000 species
Malesia 25,000 species
Australia 10,000 species
The tropics are generally much richer in species than temperate regions.
In general, area for area, the tropical flora is about twice as rich as temperate floras.
Floras in the same general latitude have about the same number of species per
area, even with considerable variation in climate.
Eastern Asiatic floras seem to have a significantly higher percentage of species
in primitive or less advanced families.
Almost 50 % of all Angiosperm (flowering plant) families are tropical in occurrence.
About 75 % of all Angiosperm families can be considered as primarily adapted to
tropical environments.