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LAB #6 
Phyla PTERIDOSPERMOPHYTA, CYCADOPHYTA, AND GINKGOPHYTA
  • The Primitive Gymnosperms
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"The term "gymnosperm"
  • The term "gymnosperm" literally means "naked seed", or unprotected seed.  Although difficult to define precisely, it is usually taken to include all those plants whose seeds are borne on, rather than in, specific organs of the sporophyte plant.  To be more precise, the ovules, which mature into seeds are borne in an exposed position on the sporophylls.
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"Phylum"
  • Phylum: Pteridospermophyta (extinct)
  • Medullosa sp.
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"Alethopteris (fossils of frond..."
  • Alethopteris (fossils of frond).
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"Neuropteris (fossils of frond..."
  • Neuropteris (fossils of frond).
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"Phylum"
  • Phylum: Cycadophyta
  • Cycas sp.
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"Cycas sp"
  • Cycas sp. leaflet X.S
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"Cycas sp"
  • Cycas sp. leaflet X.S
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"Cycas sp"
  • Cycas sp. Root XS
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"Cycas sp"
  • Cycas sp. X.S. of a microsporophyll
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"Cycas sp"
  • Cycas sp. (microsporangia)
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"Cycas sp"
  • Cycas sp. (megasporophylls)
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"Cycas sp"
  • Cycas sp. (megasporophylls)
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"Zamia sp"
  • Zamia sp.
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"Zamia sp"
  • Zamia sp. leaflet X.S
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"Zamia sp"
  • Zamia sp. - microstrobili
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"Zamia sp"
  • Zamia sp. - microsporangia
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"Zamia sp"
  • Zamia sp. megastrobili
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"Zamia sp"
  • Zamia sp. Ovules
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"Zamia sp"
  • Zamia sp. Ovule
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"Zamia sp"
  • Zamia sp. Ovules
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"Zamia sp"
  • Zamia sp. Ovules
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"Zamia sp"
  • Zamia sp. Archegonia
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"Zamia sp"
  • Zamia sp. Seeds
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"Phylum"
  • Phylum: Ginkgophyta
  • This Phylum has only one extant species, Ginkgo biloba.  Ginkgo biloba, "the maidenhair tree", has been called a living fossil.  There is considerable doubt whether it occurs in habitats where it is not cultivated, but there are reports of wild specimens in some remote regions of China.
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"Examination of the branches in..."
  • Examination of the branches in a leafy condition reveals that there is a dimorphism of branching.  The elongate main axes are known as long shoots.  The older portions of the long shoots bear a number of short lateral branches, the short shoots, (or spur shoots).
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"The leaves of the seedlings..."
  • The leaves of the seedlings are deeply lobed, and those of the short shoots are almost entire.
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"Ginkgo biloba – life cycle"
  • Ginkgo biloba – life cycle
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"Ginkgo biloba - microsporangia"
  • Ginkgo biloba - microsporangia
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"Ginkgo biloba - microsporangia"
  • Ginkgo biloba - microsporangia
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"Ginkgo biloba ovules"
  • Ginkgo biloba ovules
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"Ginkgo biloba seeds"
  • Ginkgo biloba seeds