Transcript Gymnosperms
Please do not put your backpacks, books, or clothes on the tables where the microscopes are. Thanks! If you need a map for Saturday’s field trip, please pick one up from the front desk. Gymnosperms (non-flowering seed plants) EKU BIO 131 Gymnosperms • Phylum Ginkgophyta Ginkgo – the only species is Ginkgo biloba • Phylum Cycadophyta the cycads • Phylum Coniferophyta (or Pinophyta) the conifers • Phylum Gnetophyta the gnetophytes Ginkgo ovule and seed development Ginkgophyta microsporangia on male tree Leaves and seeds ripe seeds cleaned seeds (sometimes called “Ginkgo nuts”) germinating seeds Cycadophyta sporophytes Two explorers with the only wild specimen of Encephalartos woodii ever discovered. It was first discovered in the early 1700s. Cycad cones seed cones pollen cones Encephalartos woodii Cycad sporangia and coralloid roots note microsporangium, tapetum, microspores coralloid roots note integuments, megasporangium, Female gametophyte root with zone of symbiotic cyanobacteria Coniferophyta Pollen cone buds of Japanese Black Pine (at about meiosis time) pollen cone buds (the dark spots are the tips of the microsporophylls) buds containing needles photo by Ross Clark Coniferophyta Pine pollen development be able to identify all structures Pine ovule development be able to identify all structures Coniferophyta Gnetophyta: Gnetum notice stamens and ovules (plant is monoecious) seeds Gnetophyta: Ephedra female male seeds (Ephedra is dioecious.) Ephedrine is potentially dangerous. Gnetophyta: Welwitschia Welwitschia is definitely one of the world’s most unusual plants! Here is Welwitschia’s only habitat: the Namibian Desert, one of the driest deserts in the world. Welwitschia is one of The world’s rarest plants. Most of the following photos were taken by Terry Huff, an EKU graduate student. photo by Terry Huff Gnetophyta: Welwitschia Welwitschia has two leaves. They have basal meristems. The leaves eventually become separated into tattered segments. Welwitschia is dioecious. This is a female plant. Note the ovulate (seed) cones, and compare them with the pollen cones on the next slide. photo by Terry Huff Here is a young plant. Young plants are extremely rare. Note the two leaves. photo by Terry Huff Gnetophyta: Welwitschia photo by Terry Huff Here is a male plant. Note the smaller pollen cones. photo by Terry Huff Gnetophyta: Welwitschia photo by Terry Huff Here are some female (seed) cones, together with the small bugs that live on Welwitschia and may help to pollinate it. photo by Terry Huff photo by Terry Huff Gnetophyta: Welwitschia photo by Terry Huff Here are some female cones, together with the small bugs that live on Welwitschia and may help to pollinate it. photo by Terry Huff photo by Terry Huff Here are some very young seed cones, at about pollination time. Gnetophyta: Welwitschia photo by Terry Huff Here is another nice photo of a plant loaded with seed cones. Very few of the seeds germinate, because of the extreme environmental conditions in the Namibian Desert. photo by Terry Huff photo by Terry Huff Why so many photos of Welwitschia? -- because these photos by Terry Huff are some of the best photos ever taken of Welwitschia in its native habitat. They are better than any other photos you will find in any textbooks or on the web. Terry said he was told there were fewer than 20 Welwitschia plants remaining in their native habitat.