Transcript Gymnosperms
Gymnosperms: naked seed plants I. Characteristics of Gymnosperms A. Gymnosperms include: pines, firs, spruces, ginkgos, and cycads. B. Possession of a true seed. C. Contain secondary growth that forms woody stems D. No water necessary for sperm to reach egg. E. Leaves usually needle-like; exceptions exist. F. Sweden’s pines produce 75,000 tons of pollen each Spring. II. Division Pinophyta A. Pines reproduce using male and female cones on the same tree. B. The first artificial Christmas trees were sold by Sears and Roebuck C. The oldest living plants in the world are Bristlecone pines. One is 4,737 years old. D. Female pine cones and male cones contain 1n or haploid sex cells before fertilization. E. After fertilization, the female cones develop 2n diploid seeds. F. The state flower of Maine is the cone of the White Pine. G. Female pine cones contain a pollination droplet in their ovules to capture pollen grains. Eastern Redcedar Typical Pines White Pine Blue Spruce Juniper with “berries” Bristlecone Pines are the oldest living plants in the world. III. Division Ginkgophyta A. Ginkgos are also known as the Maidenhair Trees B. They are extinct in the wild. C. Ginkgo seeds are very fleshy, smell terrible, and are only found on female trees. D. Ginkgos lose all of their leaves every fall, the only completely deciduous division in all of the Gymnosperms. E. Ginkgos are dioecious, meaning they have separate male and………………………… female trees. In the fall, ginkgo trees are greatly loved for their yellow foliage, though females are not usually planted. You can distinguish a Ginkgo from other gymnosperms by its fan shaped and bi-lobed leaves. All Ginkgo trees have a relatively primitive vascular system. The veins continuously divide into twos. This vein pattern (dichotomous venation) is unique to the Ginkgo. IV. Division Cycadophyta: A. Cycads are all dioecious, as are the ginkgos. B. The ONLY wild Cycads in the USA are in Florida, though they can be grown ornamentally in other areas. C. Cycads have the largest sperm in the Plant Kingdom D. Cycads are very ancient and grow very slowly V. Division Gnetophyta A. One example of these plants, Welwitschia, is found only in the deserts of Namibia. It gets its very limited supply of water from warm air currents and fog. B. The gnetophytes are very bizarre and very distinctive. VI. Economic Importance A. Taxol is a cancer curative that comes from the Pacific Yew. B. Before the 1860’s newspapers were made from rags. C. Americans could save 1 million trees a year if toilet paper were cut narrower. D. The kauri pines of New Zealand produce amber (also called Dammar), the only jewel produced by plants. E. Turpentine comes from pines and is a major paint and varnish solvent F. Turpentine also produces extracts for lemon pudding. G. Americans use 200,000 tons of paper each day. H. John Muir helped found the Sierra Club to save the great forests of the west. Ancient ant or wasp trapped in amber Raw amber to be used for polishing into jewelry Goodbye! That’s all Folks! TEST NEXT TIME!