Plant
Classification
Evolutionary Ordering of Plant Groups
A cladogram of the evolutionary relationships of land plants (embryophytes) and possible origination during geologic time. The phylogenetic relationships are based upon studies that incorporate fossil taxa, which may give different results than purely molecular cladistics. The thick-labeled bars indicate evidence for macrofossils of each group during geologic time.
Below you will find the evolutionary or phylogenetic groupings of land plant groups, based upon current research. Click on a group to learn about their characteristics, time range, and evolutionary significance.
† = Extinct; * Diverts to Plant Diversity website
Classification
Nematophytes: strange, fungal-algal organisms from the Paleozoic
Archaeplastida *: clade including red algae, green algae, and land plants
├Red algae *: The phylum Rhodophyta
└Viridiplantae *: a clade including the green algae and land plants
├Chlorophytes *: some green algae
└Streptophytes: a clade including land plants, the charophytes, and zygnematophytes
├Charophytes: a group green algae closely-related to land plants
└Embryophytes: another name for "land plants"
├Bryophytes *: non-vascular plants
├Hornworts *: non-vascular thalloid plants with horn-like sporophytes
└Setaphytes: non-vascular plants with a seta stalk
├Liverworts *: non-vascular plants with thalloid and leafy forms
└Mosses *: non-vascular leafy plants
└Polysporangiophytes: plants with sporophytes that branch
├Eophytes †: branching, non-vascular plants
├Horneophytes †: branching, non-vascular plants
├Aglaophyton †: branching, non-vascular plants
└Tracheophytes: another name for the clade of vascular plants
├Rhyniales †: ancestral vascular plants
└Eutracheophytes: clade of "true" vascular plants
├Cooksonioids †: oldest known vascular plants
├Lycophytes: clade with clubmosses and zosterophylls
├Zosterophylls †: leafless relatives of clubmosses
└Sawdoniales †: derived zosterophylls
├?Barinophytes †: heterosporous zosterophylls?
└Lycopsida: the clubmosses or lycopods
├Drepanophycales †: ancestral, extinct clubmosses
├Protolepidodendrales †: extinct clubmosses with forked leaves
├Lycopodiales *: ground pines, princess pines, etc.
├Selaginellales *: spikemosses
├Isoetales *: quillworts
├Pleuromeiales †: Mesozoic group of cormose clubmosses
└Lepidodendrales †: tree-sized clubmosses, called scale trees
└Euphyllophytes: a clade of true-leaved plants
├Trimerophytes †: ancestral euphyllophytes that probably form a grade
└Eophyllophyton †: early plant with megaphyllous leaves
├Monilophytes: a clade representing modern and ancient ferns, as well as horsetails
├Cladoxylopsida †: ancient tree-sized fern-like plants
├Iridopteridales †: intermediates between trimerophytes and horsetails
└Pseudosporochnales †: a group of the earliest known tree-sized plants
└Eospermatopteris †: earliest known tree-like plant on Earth
├Equisetophytes: horsetails, scouring rushes, and their ancient relatives
├Pseudoborniales †: the most ancient group of equisetophytes
├Sphenophyllales †: horsetail-like plants with ambiguous connections
└Equisetales: Modern horsetails, including ancient calamites
├Stauropteridales †: Ancient ferns with obscure leaf-stem transition
├Rhacophytales †: Ferns dominant in Late Devonian understory
├Zygopteridales †: Late Paleozoic ferns with quadriserate fronds
├Psilotales *: leafless and rootless extant ferns
├Ophioglossales *: obscure ferns related to Psilotales
├Marattiales: ancient tree ferns with eusporangia
└True ferns *: modern ferns mostly with leptosporangia
├Pertica †: taxon intermediate between early forms and woody plants
└Lignophytes (woody plants)
├ Progymnosperms †: spore-bearing, woody plants
├? Eophyllophyton †: Early Devonian plant with true leaves that are flattened stems
├Aneurophytales †: vine-like, leafless progymnosperms
├Stenokoleales †: Possible progymnosperm or seed plant
├Archeopteridales †: earliest true trees with woody growth
├Protopityales †: obscure progymnosperms known mostly from anatomy
└Noeggerathians †: heterosporous progymnosperms dominant during Permian
└ Spermatophytes (seed plants)
├Basal seed plants †: Late Devonian seed plants, known as seed ferns
├Lyginopteridales †: early arborescent seed ferns
├Medullosales †: early arborescent seed ferns with large seeds
├Buteoxylonales †: poorly understood pteridosperm groups
├Callistophytales †: Best known Paleozoic seed plants
├Calamopityales †: Mississippian pteridosperm with indistinct stem and leaf anatomy
├Cycadales: palm-like, cone-bearing plants that are still extant on Earth
├Dirhopalostachtaceae †:
├Gigantopteridales †: complex seed ferns of the Permian
├Nystroemiaceae †: Permian seed plants with derived stems and leaves
├Hermanophytes †: enigmatic gymnosperms from the Late Mesozoic
├Iraniales †: obscure gymnosperms from the Late Triassic
├Peltaspermales †: gymnosperms with umbrella-like reproductive structures
├Corystospermales †: successful fern-like gymnosperm during the Triassic
├Czekanowskiales †: Mesozoic seed plant that may be related to ginkgoes
├Ginkgophyta: Ginkgo; maidenhair trees
├Vladimariales †: Mesozoic seed plants
├Vojnovskyales †: gymnosperm with umbrella-like cone and fan-shaped leaves
├Coniferophytes: conifer clade
├Cordaitales †: Paleozoic gymnosperms with cones and strap-like leaves
├Voltziales †: ancestral conifers
└Conifers: extinct and extant cone-bearing, (mostly) evergreen gymnosperms
├Gnetophytes *: gymnosperms with angiosperm-like leaves and cones
└?Anthophyte clade: hypothesized clade of plant groups related to angiosperms
├Glossopteridales †: Permian gymnosperms with tongue-like leaves
├Petriellales †: Triassic plants found in Antarctic understory
├Pentoxylon †: Mesozoic gymnosperms with complex leaves and pulpy cones
├Bennettitales †: cycad-like gymnosperms with flower-like cones
├Doyleales †: obscure Cretaceous gymnosperm with carpel-like ovulate organs
├Caytoniales †: small trees with possible affinities with angiosperms
└Angiosperms: flowering, fruiting plants
