vascular plants without seeds

early vascular plants

lycophytes

euphyllophytes

vascular cryptograms

rhyniophytes

zosterophyllophtes

heterospory

trimerophytes

origin of megaphylls

monilophytes

equisetophytes

ferns

upright stems

short cylinders

no leaves

equal dichotomous branching

are homosporous

lateral sporangia

sporangia opened transversely

cones and strobili together

lepidostrobus

lepidophloios

morphology

extant genera

lycopodium

selaginella

isoetes

herbs with prostate rhizomes

true roots and short upright brances

secondary growth never occurs

homosporous

heterosporous

ligules on leaves ligule

heterosporous

microphylls have ligules

small corm like stems with roots

sporophyte is single axis that bears both true roots and megaphyllous leaves

endarch siphonostele

leaf gap