BIOL 420 1st Edition Lecture 9Seedless Vascular PlantsFerns and Their AlliesText Reference: Chapter 17Seedless Vascular Plants – ferns, club mosses, horsetailsTrends in the Evolution of Plants- Vascular tissue develops relatively early- Lignin added as a component of cell walls, (early plants turgor pressure)- Xylem accumulates as wood- Sprorophyte (2N) stage becomes conspicuous (dominant)- Bryophyte sporophyte produces single, unbranched sporangia; vascular plant sporophyte produces numerous sporangia- Vascular plants became more sophisticated developing roots, stems, and leaves- Free-swimming sperm cell eliminated in gymnosperms and angiosperms- Development of seeds in gymnosperms and angiosperms- Development of flowers and fruits in angiospermsOrganization of the Vascular Plant Body- Earliest vascular plants lacked roots and leaves- Roots, shoots, leaves- Three embryonic tissue systems in vascular plants1. Dermal tissue: makes up the outer, protective covering of the plant2. Vascular tissue: comprises the conductive tissues (xylem and phloem) and is embedded in the ground tissue systema. Ground tissue: where the differences in the structures of the root, stem and leafi. Growth Patterns of Vascular PlantsPrimary Growth – growth that occurs relatively close to the tips of roots and stems. Initiated bythe apical meristems and is primarily involved with extension of the plant body – often the ventricle growth of a plant. Secondary Growth – thickening the stem and rootVascular cambium – produces secondary vascular tissuesCork cambium – which forms a periderm (cork tissue): replaces the epidermis as the dermal tissue system Vascular Tissue1. Xylema. Tracheids: only type of water-conducting cell in most vascular plants; provide channels for the passage of water and minerals and provides support.b. Vessels: water-conducting cells in angiospermsc. Pith: a central column of ground tissued. Stele: make up the central cylinder;Roots and Leaves1. Microphylls: small leaves that contain only a single strand of vascular tissue2. Megaphylls: larger; associated with stems, the blade has a complex system of branching veinsReproductive Systems of Vascular Plants1. Homospory: horsetail, produces bisexual gametophytes that bear both sperm-producing gametophytes that bare both sperm and egg producing cells2. Heterosporya. Microspores: give rise to male gametophytesb. Megaspores: give rise to female gametophytesGametophyte StageBecomes smaller and dependent on sporophyteCarboniferous Swamp ForestsLycophytes, horsetails, fernsEssay: Coal Age PlantsLycophyte trees: grow in heights of 10 – 35 metersCalamites: giant horsetails, equistem, underground rhizome system, the leaves and branches were whorled at the nodes, Tree ferns: represented in fossil recordPhylum Lycopodiophyta – club mossesLycopodium (genus)o Range from Arctic to tropicso Life cycle – Lycopodium Sporophyte - conspicuouso Rhizomeo Microphyllso Strobiluso Sporangiumo Spores (N)o Antheridiumo Archegoniumo Symbiotic fungi- Exampleso Lycopodiumo Sellaginellao IsoetesPhylum MonilophytaFerns and horsetails- Examples (recognize as being ferns)o Lindsaea (fern)o Cyathea(tree fern)o Elaphoglossum (Peruvian fern)o Aspleniumo Pleopeltiso Cinnamon ferno Bracken fern- Life Cycle – Polypodium (fern)- Roots- Rhizome- Frond- Pinnae- Rachis- Fiddlehead- Sporophyte- Gametophyte- Sorus- Sporangium- Spores- Archegonium- Antheridium- Zygote- Vascular tissueo Xylemo Phloem- Psilotum– whisk ferns and relatives- Botrychium– grape fern- Ophioglossum– “adder’s tongue”- Psilotum– “whisk fern”- Equisetum – horsetails (structure and life cycle)o Sporangiophores: umbrella like structureso Elaters: thickened bands that arise from the outer layer of the spore wall – coil when moist and uncoil when dry.o Vegetativeshoot: o