18 Sept. 2014Ferns&Moss.ppt1 FERNS & MOSSES Spore Dispersed Plants

18 Sept. 2014Ferns&Moss.ppt2 Spore-dispersed plants Seedless, dispersion by spores Advantages of spores Cheap, each one small, requires small resource investment Produced in huge numbers Can result in huge numbers of offspring Disadvantage Wasteful, most spores unsuccessful Must land on good moist soil Little resource to support growing gametophyte

18 Sept. 2014Ferns&Moss.ppt3 Spore-dispersed vascular plants Vascular tissues, = xylem, phloem Allow growth to large size Local ferns, horsetails, club mosses not very large, fronds cm Tree ferns (tropical) to 18 m tall w/ fronds 3 m long Prehistoric club mosses tree-sized

18 Sept. 2014Ferns&Moss.ppt4 Phylum Pterophyta (Ferns)

Leafy fronds, usually compound Fronds grow as “fiddleheads” 18 Sept. 2014Ferns&Moss.ppt5

Phylum Pterophyta (Ferns) Sporangia in sori under fronds One kind of spores only  homosporous Gametophyte with both antheridia & archegonia  Antheridia release sperm before archegonia mature! 18 Sept. 2014Ferns&Moss.ppt6

18 Sept. 2014Ferns&Moss.ppt7 Phylum Sphenophyta ("horsetails" or "scouring rushes") Hollow, segmented stems Minute bristle-like gray-brown fronds Stems hard, gritty with crystals of silica (SiO 2, sand, glass)

Phylum Sphenophyta Sporangia at tips of stems in strobilus Heterosporous, two kinds of spores  separate male & female gametophytes. One living genus Equisetum 18 Sept. 2014Ferns&Moss.ppt8

18 Sept. 2014Ferns&Moss.ppt9 Phylum Lycophyta ("club mosses" or "ground pine") Short stems with microphylls,  one vein per leaf (veins don’t branch) Sporangia at tips of stems or axils of fronds in strobilus Heterosporous, two kinds of spores  separate male & female gametophytes.

18 Sept. 2014Ferns&Moss.ppt10 Phylum Lycophyta ("club mosses" or "ground pine")

18 Sept. 2014Ferns&Moss.ppt11 Spore-dispersed nonvascular plants Lack xylem or phloem  Limited ability to transport water, minerals, sugars Usually live in moist places  Some can endure drying, metabolism ceases until they are wet again.

18 Sept. 2014Ferns&Moss.ppt12 Phylum Bryophyta (Mosses) Familiar, low green soft masses on ground, usually in moist places

18 Sept. 2014Ferns&Moss.ppt13 Phylum Bryophyta (Mosses) Life Cycle (very different from ferns, etc.)  dominant GAMETOPHYTE (haploid) familiar form green, with tiny leaf-like blades, antheridia & archegonia at top of moss  zygote grows into SPOROPHYTE (diploid) = stalk + capsule Capsule dries, splits open, releases spores Spores grow into GAMETOPHYTE

18 Sept. 2014Ferns&Moss.ppt14 Moss Life Cycle

18 Sept. 2014Ferns&Moss.ppt15 Economic uses of ferns, mosses Horticulture, landscaping Peat moss (Sphagnum)  soil conditioner, holds moisture,  cut, dried, burned as fuel in Ireland, Scandinavia.

18 Sept. 2014Ferns&Moss.ppt16 Formation of a peat bog Continental glacier plows up soil Glacier breaks up as it melts back

18 Sept. 2014Ferns&Moss.ppt17 Formation of a peat bog Hole left fills with meltwater Sphagnum grows from edges, may eventually fill bog

Peat bog Sphagnum Spruce & Birch Pitcher plants 18 Sept. 2014Ferns&Moss.ppt18

Economic uses of ferns, mosses 18 Sept. 2014Ferns&Moss.ppt19 Carboniferous Period (middle Paleozoic)  Ferns, tree ferns, tree-like "horsetails," tree-like lycophytes fossilized  Coal deposits  Power for heavy industry, electrical generation

18 Sept. 2014Ferns&Moss.ppt20 Origins of plants from some green algae multicellular same photosynthetic pigments, chlorophyll a, b store food as starch cellulose cell walls alternation of generations

18 Sept. 2014Ferns&Moss.ppt21 Evolution of plants One group includes Bryophyta (mosses)  Gametophyte dominant 2nd group includes ferns & seed plants, Lycophyta—Coniferophyta  Sporophyte dominant  Vascular tissue

18 Sept. 2014Ferns&Moss.ppt22 Evolution of plants One group includes mosses, hornworts  dominant gametophyte, non-vascular 2nd group includes ferns, seed plants  dominant sporophyte, vascular tissue

18 Sept. 2014Ferns&Moss.ppt23 Challenges to terrestrial organisms (& how plants meet the challenges): 1. Getting water, water transport to cells specialized vascular tissues 2.Evaporation, drying waxes, oils in "epidermis," close stomata 3.Gravity, need for support fluid pressure in vascular tissue; lignified xylem = wood 4.Rapid temperature changes evaporative cooling requires even more water! seasonal: drop leaves or close stomata