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)
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!
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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 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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