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21.3SeedlessVascularPlants

DiversityofSeedlessVascularPlants

§ Seedlessvascularplantshavevasculartissuesfortransportingwaterandnutrients.

§ Becausetheyhavevasculartissues,seedlessvascularplantsgenerallyarelargerand

betteradaptedtodrierenvironmentsthannonvascularplants.

§ Seedlessvascularplantsreproduceusingsporesratherthanwith

seeds.

DivisionLycophyta

§ Sporophytegenerationoflycophytesisdominant.

§ Reproductivestructuresproducesporesthatareclub-shapedor

spike-shaped.

§ Haveroots,stems,andsmall,scaly,leaflikestructures

§ Manytropicallycophytesareepithytes(livesanchoredtoanotherobjectorplant)

§ Twogenera:LycopodiumandSelanginella

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DivisionPterophyta

Ferns

§ Plantdivisionincludesfernsandhorsetails

§ Mostcommoninmoistand/orshadyenvironments

§ Sporophyteisthedominantgeneration

§ Theleafofaferniscalledafrond.

§ Thesearecalledfrondstodistinguishthem

fromtheleavesoffloweringplants.

§ Sporophyteproducesrootsandathickundergroundstemcalleda

rhizome,afood-storageorgan.

§ Thefrondispartofthesporophytegenerationofferns.

§ Fernsporesforminastructurecalledasporangium.

§ Clustersofsporangiaformasorus.

§ Soriusuallyarelocatedontheundersidesoffronds.

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Horsetails

§ HorsetailsorscouringrushesarealsomembersofdivisionPterophyta

§ Ribbed,hollowstemswithcirclesofscalelikeleaves

§ Producesporesinstrobili

§ Mostgrowinwetareasorwhererootscangrowintowater