Families of Vascular Plants - Botany 307F  

Pteridophytes

"Ferns and fern allies;" "free-sporing (non-seed) plants;" "vascular cryptogams"

Morphology and ecology

Click on the groups at the right for more information about each one; groups represented in Ontario are compared below. You can also click on some of the synapomorphies for more information about the ancestral and derived states of the characters involved in each one.

Embryophyte phylogeny
 
These four groups of extant vascular cryptogams all share a life cycle in which the sporophyte is free-living, at maturity completely independent of the gametophyte. All except Psilotophyta have extensive representation in the fossil record.


Living Pteridophyte Groups found in Ontario - comparison

 

Lycopophytes

Monilophytes
  Lycopodiaceae, Selaginellaceae, ("clubmosses"), and Isoetatceae ("quillworts")

Ophioglossaceae
("adder's tongue ferns");
cf. also the Psilotaceae

Equisetaceae ("horsetails");
cf. also the Marattiaceae
- Equisetum life cycle quiz (courtesy Ruth Stockey, Lorna Ash & Bio-DiTRL)
Leptosporangiates ("ferns") - Fern life cycle quiz (courtesy Lorna Ash & Bio-DiTRL)
Sporophyte Roots present. Ophioglossaceae with mycorrhizal roots. Roots present. Roots present.
   Stem Creeping, and/or erect or pendulous (or, in Isoetes, a corm). Ophioglossaceae with dichotomously branched rhizomes, with erect, aerial branches. Rhizomatous, with erect, aerial branches. Creeping, rhizomatous, or erect (becoming tree-like in size in the Cyatheaceae).
   Leaves Spirally arranged microphylls. Spirally arranged, scale-like in Psilotum Whorled. Spirally arranged, often compound.
   Sporangia Thick-walled (eusporangiate), homosporous (Lycopodium and segregate genera) or heterosporous; in Isoetes the entire plant represents a terminal strobilus.

Thick-walled (eusporangiate), homosporous

 

Thick-walled (eusporangiate), homosporous, aggregated in a terminal strobilus Thin-walled (leptosporangiate), homosporous or, in the water ferns, heterosporous. Terminal, on axes, or on lower (abaxial) surfaces of leaves, variously aggregated.
Gametophyte Free-living (Lycopodium) or endosporic (Isoetes, Selaginella) In Ophioglossaceae, remarkably similar to the rhizomes of sporophytes; subterranean, non-photosynthetic, cylindrical, covered with rhizoids and bearing both antheridia and archegonia. Mycorrhizal. Either male, or initially female, becoming hermaphroditic; sex ratio of germinating spores apparently controlled by light intensity and crowding. Free-living or endosporic (water ferns; Marsileales, Salviniales)
Ontario
representation
Isoetes, Lycopodium, Selaginella Botrychium, Ophioglossum in Ontario, 74 spp. worldwide. Helminthostachys (1 sp.) tropical. Equisetum sole genus;
9 out of 14-15 spp. worldwide
Abundant and diverse
(>10,000 spp. worldwide)
Ecology Widely distributed, epiphytic, terrestrial, or (Isoetes) aquatic plants. Terrestrial; some tropical epiphytes. Herbaceous perennials, variously evergreen or dying back to the ground each year. Widely distributed, epiphytic, terrestrial, or (Marsileales, Salviniales) aquatic plants.
 

Images from Botany at the University of Hawaii

Images from Botany at the University of Hawaii
Images from Botany at the University of Hawaii
Images from Botany at the University of Hawaii  
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Flora North America Editorial Committee (1993) - Pteridophytes


Sporne (1975)

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Please send your comments to tim.dickinson@utoronto.ca; last updated 11-Oct-2008

Wood heterospory Leptosporangiate sporangia Heterospory, seeds lateral reniform sporangia microphylls Bryophytes Lycophytes Psilotaceae Monilophytes Marattiales Equisetales Leptosporangiate ferns Ophioglossales