chapters 21 & 22 seedless vascular and nonflowering seed plants
TRANSCRIPT
![Page 1: Chapters 21 & 22 Seedless Vascular and Nonflowering Seed Plants](https://reader035.vdocuments.us/reader035/viewer/2022062315/5697c0241a28abf838cd4716/html5/thumbnails/1.jpg)
Chapters 21 & 22
Seedless Vascular and Nonflowering Seed Plants
![Page 2: Chapters 21 & 22 Seedless Vascular and Nonflowering Seed Plants](https://reader035.vdocuments.us/reader035/viewer/2022062315/5697c0241a28abf838cd4716/html5/thumbnails/2.jpg)
Topics
• Rhyniophytes
• Evolution of stele – protostele and syphonostele
• Vascular plant cladogram
• Phylum – Lycophyta
• Phylum – Pteridophyta – life cycles
• Adaptive superiority of the seed
• Gymnosperm phyla
![Page 3: Chapters 21 & 22 Seedless Vascular and Nonflowering Seed Plants](https://reader035.vdocuments.us/reader035/viewer/2022062315/5697c0241a28abf838cd4716/html5/thumbnails/3.jpg)
Early Vascular Plants: Extinct Rhyniophytes
• Cooksonia spp. - branching sporophyte – homosporous
• Rhynia and Aglaophyton were other Rhyniophytes, early vascular plants similar to Cooksonia
• Today sporangia on vascular plants are lateral – not terminal
![Page 4: Chapters 21 & 22 Seedless Vascular and Nonflowering Seed Plants](https://reader035.vdocuments.us/reader035/viewer/2022062315/5697c0241a28abf838cd4716/html5/thumbnails/4.jpg)
Early Vascular Plants• Similarities between the hornworts and vascular plants
make Anthoceros the possible ancestors of vascular plants – inner vascular cylinder = stele
• Protostele (solid – no pith) evolved first – two types
Endarch – central protoxylem Exarch – central metaxylem
Lycophyte roots Lycophyte stems, seed plant roots
cortex
cortexepidermis
epidermis
stele
![Page 5: Chapters 21 & 22 Seedless Vascular and Nonflowering Seed Plants](https://reader035.vdocuments.us/reader035/viewer/2022062315/5697c0241a28abf838cd4716/html5/thumbnails/5.jpg)
• Later another type of stele, siphonostele – central pith - stems of ferns and seed plants - will discuss in plant tissues later
Microphylls from enations/scalesMegaphylls from branch systems
![Page 6: Chapters 21 & 22 Seedless Vascular and Nonflowering Seed Plants](https://reader035.vdocuments.us/reader035/viewer/2022062315/5697c0241a28abf838cd4716/html5/thumbnails/6.jpg)
Selaginella sp.Lycopodium sp.(ground pine, club moss)
Label – Strobilus axis,sporangium, seta, sporophyll, spores
HOMOSPORY
Phylum - Lycophyta
Label – Strobilus axis,microsporangium, megasporangium, seta, microsporophyll, megasporophyll, microspores, megaspores
HETEROSPORY
![Page 7: Chapters 21 & 22 Seedless Vascular and Nonflowering Seed Plants](https://reader035.vdocuments.us/reader035/viewer/2022062315/5697c0241a28abf838cd4716/html5/thumbnails/7.jpg)
Psilotum spp. Whisk ferns
Phylum - Pteridophyta – Ferns and allies
![Page 8: Chapters 21 & 22 Seedless Vascular and Nonflowering Seed Plants](https://reader035.vdocuments.us/reader035/viewer/2022062315/5697c0241a28abf838cd4716/html5/thumbnails/8.jpg)
Equisetum spp.Horsetails
Strobilus
![Page 9: Chapters 21 & 22 Seedless Vascular and Nonflowering Seed Plants](https://reader035.vdocuments.us/reader035/viewer/2022062315/5697c0241a28abf838cd4716/html5/thumbnails/9.jpg)
Fern stem
Fern root
Ferns - >12,000 spp.
![Page 10: Chapters 21 & 22 Seedless Vascular and Nonflowering Seed Plants](https://reader035.vdocuments.us/reader035/viewer/2022062315/5697c0241a28abf838cd4716/html5/thumbnails/10.jpg)
![Page 11: Chapters 21 & 22 Seedless Vascular and Nonflowering Seed Plants](https://reader035.vdocuments.us/reader035/viewer/2022062315/5697c0241a28abf838cd4716/html5/thumbnails/11.jpg)
Ferns: Life Cycle
![Page 12: Chapters 21 & 22 Seedless Vascular and Nonflowering Seed Plants](https://reader035.vdocuments.us/reader035/viewer/2022062315/5697c0241a28abf838cd4716/html5/thumbnails/12.jpg)
Gymnosperms
• Heterospory - Megasporangium to megaspore to megametophyte to archigonium – all in ovule = egg and other cells = megagametophyle - retained inside the maternal sporophyte
• Fertilized ovule = sporophytic embryo - could use the photosynthetic and absorptive capacity of leaves and roots of mother sporophyte – rather than depending on a tiny haploid gametophyte
Seed ferns are all extinct
Seed – superior propagation
![Page 13: Chapters 21 & 22 Seedless Vascular and Nonflowering Seed Plants](https://reader035.vdocuments.us/reader035/viewer/2022062315/5697c0241a28abf838cd4716/html5/thumbnails/13.jpg)
Seed
• Fertilized ovule covered by its integument - seed coat
• Embryonic sporophyte
• Nutritive tissue to nourish sporophyte
• Dormant period
• Not covered by an ovary = Gymnosperms
Gymnosperms <1000 spp.
Four phyla
![Page 14: Chapters 21 & 22 Seedless Vascular and Nonflowering Seed Plants](https://reader035.vdocuments.us/reader035/viewer/2022062315/5697c0241a28abf838cd4716/html5/thumbnails/14.jpg)
Phylum - Cycadophyta: Cycads • Only ~100 species today• Almost all tropical • Dioecious – seed cones
and pollen cones on
separate plants
![Page 15: Chapters 21 & 22 Seedless Vascular and Nonflowering Seed Plants](https://reader035.vdocuments.us/reader035/viewer/2022062315/5697c0241a28abf838cd4716/html5/thumbnails/15.jpg)
Phylum Coniferophyta = PinophytaMost diverse Gymnosperms - >550 spp.
All moderate to extremely large trees (Sequoia spp. - largest organisms on planet)
Mainly monoecious
![Page 16: Chapters 21 & 22 Seedless Vascular and Nonflowering Seed Plants](https://reader035.vdocuments.us/reader035/viewer/2022062315/5697c0241a28abf838cd4716/html5/thumbnails/16.jpg)
![Page 17: Chapters 21 & 22 Seedless Vascular and Nonflowering Seed Plants](https://reader035.vdocuments.us/reader035/viewer/2022062315/5697c0241a28abf838cd4716/html5/thumbnails/17.jpg)
![Page 18: Chapters 21 & 22 Seedless Vascular and Nonflowering Seed Plants](https://reader035.vdocuments.us/reader035/viewer/2022062315/5697c0241a28abf838cd4716/html5/thumbnails/18.jpg)
Phylum - Ginkgophyta: Maidenhair Tree
• single living species, Ginkgo biloba
• Broad leaves – veins dichotomously branched – not reticulate
• Dioecious – seeds not on cones – emits butric acid – foul odor
• Native to China – medicinal uses
![Page 19: Chapters 21 & 22 Seedless Vascular and Nonflowering Seed Plants](https://reader035.vdocuments.us/reader035/viewer/2022062315/5697c0241a28abf838cd4716/html5/thumbnails/19.jpg)
Phylum - Gnetophyta ~ 70 spp.
Gnetum spp. Ephedra spp.
Welwitschia mirabilisOnly sp. in genus
Vessels and sieve tubes
Similarity to Anthophytes
Many – dioecious some - monoecious