Plant Diversity II – Ch. 29 Lecture Objectives 1.Intro to Seedless Vascular Plants 2. Divisions Lycophyta and Monilophyta

Bryophytes Ruled the Land for 100 million years……..until the Seedless Vascular Plants

Similarities & Differences between Bryophytes and Seedless Vascular Plants Dominant generation = Sporophyte Branched Sporangia Vascular Tissues Xylem Phloem Increase in height Primary & secondary growth Organs Leaves, stems, and roots Cuticle Alternation of Generations Stomata Dependent upon water for reproduction

Seedless vascular plant adaptations Branched Sporangia Vascular Tissues Xylem Phloem

Seedless vascular plant adaptations con’t. Leaves Sporophyll  modified leaf w/ sporangia Sori Strobili Homosporous Single spore type  bisexual gametophyte Heterosporous Megasporangium Megaspore  female gametophyte Microsporangium Microspore  male gametophyte Microphyll Megaphyll

Seedless Vascular Plants Lycophyta Monilophyta

Division Lycophyta - the Lycophytes Quillwort - heterosporous Spike “Moss” Club “Moss” (heterosporous) -(homosporous) Lycopodium sp. * Epiphytic * Microphylls

D: Lycophyta con’t. - life cycle

Division Monilophyta Ferns Horsetails Whisk Ferns Equisetum sp. Psilotum sp.

Division Monilophyta - the ferns - Underside of frond/megaphyll - note sori (mostly homosporous) Fiddle Head - sporophyte - gametophyte

Fern Life cycle Key Haploid (n) Diploid (2n) Spore (n) Figure 29.11 Fern Life cycle Key Haploid (n) Diploid (2n) Spore (n) Young gametophyte Antheridium Spore dispersal MEIOSIS Rhizoid Underside of mature gametophyte (n) Sporangium Sperm New sporophyte Sporangium Archegonium Mature sporophyte (2n) Egg Zygote (2n) Figure 29.11 The life cycle of a fern FERTILIZATION Sorus Gametophyte Fiddlehead (young leaf)

D: Monilophyta con’t. The Horsetails Equisetum sp. “Scouring Rush” Separate vegetative & reproductive stems Homosprous Air canals Rings of small leaves

D: Monilophyta con’t. The Whisk Ferns Note dichotomous branching stems  no roots 3 fused sporangia  yellow knobs homosporous

Importance of seedless vascular plants Increased growth & photosynthesis  removed CO2 from the atmosphere contributed to global cooling at the end of the Carboniferous period The decaying plants of these Carboniferous forests eventually became coal