Tuesday, August 21, 2012

Taxonomy of Gymnosperms

Last week I posted a summary of some of the taxonomical parts of the Angiosperms, the flowering seed plants.  My look at botanical taxonomy continues today with the other major group of seed plants -- the Gymnosperms or non-Flowering seed plants.

In reality, seed plants are considered by many taxonomists and botanists to be a superdivision within the plant kingdom.  Within this superdivision are five divisions (phyla).  Of these, the Angiosperm make but one division -- the other four are customarily linked as the Gymnosperm divisions.  They are, then, the non-flowering vascular seed plants.

Eastern White Pine (Pinus strobus) &      Sago Cycad (Cycas revoluta)

File:Ginkgo Biloba Leaves - Black Background.jpgFile:Welwitschia mirabilis(2).jpg
Gingko or Maidenhair Tree (Gingko biloba) &  Welwitschia (Welwitschia mirabilis)

I present here a summary of these four divisions of non-flowering seed plants.  Note, of course, that taxonomy, or the categorizing of living things, is not an area of total agreement and that my list is not exhaustive when it comes to families and the like.  Enjoy!


Kingdom Plantae
Subkingdom Tracheobionta [Vascular Plants]
Superdivision Spermatophyta [Seed Plants]

Division Coniferophyta [Conifers]
·         Class Pinopsida
o   Order Pinales
§  Family Araucariaceae [Araucaria family]
§  Family Cephalotaxaceae [Plum Yew family]
§  Family Cupressaceae [Cypress family; cypress, red-cedar, some claim Taxodiaceae]
§  Family Pinaceae [Pine family; pine, spruce, fir, cedar, hemlock]
§  Family Podocarpaceae [Podocarpus family]
§  Family Taxodiaceae [Redwood family; redwood, sequoia, baldcypress]*
o   Order Taxales
§  Family Taxaceae [Yew family]

Division Cycadophyta [Cycads]
·         Class Cycadopsida
o   Order Cycadales
§  Family Cycadaceae [Cycad family]
§  Family Zamiaceae [Zamiad or Coontie family]

Division Ginkgophyta [Ginkgo]
·         Class Ginkgoopsida
o   Order Ginkgoales
§  Family Ginkgoaceae [Ginkgo family]
·         Ginkgo biloba (Maidenhair-tree; only living species)

Division Gnetophyta [Gnetophytes]
·         Class Gnetopsida
o   Order Ephedrales
§  Family Ephedraceae [Mormon-tea family]
o   Order Gnetales
§  Family Gnetaceae [Gnetum family]
o   Order Welwitschiales*
§  Family Welwitschiaceae [Welwitschia family]
·         Welwitschia mirabilis

Nota bene: taxonomy is always a matter of debate and discussion – you may find different arrangements than those listed here.
Source: United States Department of Agriculture: http://plants.usda.gov/classification.html ; *- added from other sources.


Live well!

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