Biology of Plants

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Phylum Pterophyta

• 4 types of ferns
• O. Ophioglossales and Marattiales
• eusporangiate
• O. Ficales
• homosporous leptosporangiate
• O. Marsileales and Salviniales
• heterosporous leptosporangiate
• O. Psilotales
• reduced fern

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Orders Ophioglossales and Marattiales

• Only eusporangiate orders
• Ophioglossales 3 genera
• Botrychium (grape fern)
• Ophioglossum (adders tounge)
• early divergent
• most chromosomes of ANY living organism (1260)
• northern temperate
• 1 leaf/year
• leaf vegetative blade (dissected or undivided)
  fertile stalk (dissected or undivided)
• gametophytes
• subterranean/tuberous/elongate
• w/ rhizoids and have endophytic assoc.
• Marattiales 6 genera, 200 sp.
• tropics, includes extinct tree fern

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Order Filicales

• Leptsporangiate, homosporous
• Most familiar ferns
• 35 families, 320 genera, 10,500 sp.
• Siphonostelic rhizomes, adventitious roots, new
  sets of lvs each yr
• Frond leaf, megaphyll, ? SAV
• typically lvs are compound lamina divided into
  leaflets (pinnae) attached to rachis
• fiddlehead coiled lvs
• circinate vernation uncoiling of lvs
• func. protection of embryonic leaf tip
• protected by hairs or scales (epidermal
  outgrowth)
• used to classify ferns

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Order Filicales

• Sporangia on leaf margins or lower surface
• modified leaves, or special stalks
• sori/sorus cluster of sporangia
• yellow, orange, brown, black
• lines, dots, patches
• sori covered by leafy outgrowth
  indusia/indusium
• used to classify ferns

Sensitive fern
bracken fern
??????
wood fern
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Order Filicales

• Gametophytes free-living, bisexual
• flat, ? shaped w/ rhizoids (prothallus)
• moist locations
• antheridia among rhizoids, archegonia near crotch
  (outcrossing and inbreeding)
• flagellated sperm
• Sporophyte embryo dependent on gametophyte
• Sporophyte is perennial,
  gametophyte is short-lived
• few sp. only gametophytic
• repro. via gemmae
  (veg. outgrowth)

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Orders Marsileales and Salviniales

• Leptsporangiate, heterosporous
• Water ferns
• 2 orders, 5 genera
• Mud, damp soil, floating
• Sporocarps drought resistant, germinate to
  produce sori chains
• Azolla N fixing, impt for other
  plants

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Order Psilotales

• 2 living genera
• Simple morphology evolved from complex morphology
• Psilotum (whisk fern) SE and SW US
• lacks roots/lvs
• dichotomously branched above-/belowground
• rhizomes and rhizoids
• homosporous
• bisexual gametophytes
• flagellated sperm
• Endomycorrhizal
• Protostele

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Order Psilotales

• Tmesipteris Australia/NZ
• Epiphytic

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Order Equisetales

• 300 MYA
• Trees extinct
• 1 genera Equisetum (horsetail, scouring rush), 15
  sp.
• oldest genera on Earth?
• riparian, moist areas
• jointed stems, rough texture
• scouring rush
• whorled, small, scalelike lvs
  (microphylls)
• some branching
• silicon in epidermal cells
• adventitous roots, rhizomes

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Order Equisetales

• hollow pith w/ ring of carinal canals
• X/P around carinal canals

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Order Equisetales

• homosporous
• sporangiophores fertile stems w/ sporangia,
  lack chlorophyll
• or strobili on veg. stem tips
• elaters
• free-living gametophyte
• bisexual but cross-fertilization
• archegonia and antheridia in bisexual
  gametophytes mature different
  times
• water required for fertilization

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