1. Early vascular plants (fossil record) branched sporophytes –dichotomous branching –terminal sporangia rhizome = horizontal stem still attached via rhizoids –eventually roots, evolved stem but no leaves lignified water conducting cells

2. modern “seedless vascular plants” (grade not clade) homeohydry; lignified H 2 O conducting cells branched sporophytes –dichotomous branching in lycophytes –non-dichotomous branching in ferns –subterminal sporangia rhizomes & roots leaves –microphylls (one vein) in lycophytes –megaphylls (branched veins) in ferns –sporophylls leaves that bear sporangia

3. life cycle of seedless vascular plants gametophyte small, short-lived sporophyte prominent –specialization for spore dispersal gametophyte roots leaf stem = rhizome sporophyte

4. bryophytes seedless vasc plants gphyte prominent sphyte prominent no lignified vasc. tissuexylem w/lignin poikilohydry homeohydry roots in sporophyte rhizoids in gametophyte spores for dispersal water for fertilization

5. sex in seedless vascular plants homospory heterospory one type of sporangium & spore gametophyte w/archegonia & antheridia gametophytes develop outside spore wall some lycophytes, most ferns megasporangium w/ megaspores (food) --> gphyte w/archegonia microsporangium w/ microspores (travel) --> gphyte w/antheridia gametophytes develop inside spore wall most lycophytes, water ferns arose several times 1st step in evol of seeds

6. extant seedless vascular plants 1. lycophytes Lycopodium and relatives –temperate forest floor, bogs –tropical epiphytes Selaginella diverse habitats –incl model organism Isoetes –small, aquatic now; big fossil trees

7. extant seedless vascular plants 2. Pterophytes (ferns) including: Psilotum (whisk fern) Equisetum (horsetail, scouring rush) –big fossil trees tree ferns, water ferns

8. fossil seedless vascular plants Carboniferous forests 290-360 mya fossil fuels (esp. coal) –plants died, didn’t decay (stored C) –global cooling “coal ball” = rock w/fossil plants –NOT compressed into coal –macrofossils w/fine details preserved