Vascular Plants 1. Internal conducting tissue (xylem & phloem) 2. True leaves 3. Roots for absorption, as well as anchorage 4. Gametophyte reduced, sporophyte dominant 5. Primitive vascular has no seeds, spores instead
Jan 05, 2016
Vascular Plants
1. Internal conducting tissue (xylem & phloem)
2. True leaves
3. Roots for absorption, as well as anchorage
4. Gametophyte reduced, sporophyte dominant
5. Primitive vascular has no seeds, spores instead
Major Divisions• Psilotophyta – whisk ferns
• Lycophyta – club moss, quillworts, ground pines, spike pines,
• Sphenophyta – horsetails
• Pterophyta – ferns
Psilotophyta• Whisk ferns – Simplest vascular plant, no
leaves or roots. Fossil records from 400 mya
– Structure• Forking stem, arise from rhizomes• Enations – tiny green leaf-like tissue without
veins, spirally arranged• Photosynthetic stem, core of xylem & phloem
Psilotophyta• Reproduction –
– Sporangia releases spore, sporophyte generation visible
– Gametophyte generation minute, not visible
Psilotophyta
• Habitat – – Tropical & subtropical, southeastern U.S.
Lycophyta (Club mosses, Quillworts, Ground Pine, Spike Pines)
• True stems & leaves• Microphylls = small leaves• Structure
– Ground pine resembles little Christmas trees
– Leaves are whorled– Stems arise from rhizomes, as
well as adventitious roots– Cone-like reproductive structure
Lycophyta• Reproduction
– Sporophyll – sporangium bearing leaves produce spores by meiosis
– Strobili – cone like structure contains spores from meiosis
Lycophyta
• History & uses– Flashbulb powder– Powder can stop bleeding– Ornamental – floral design, Christmas decorations
• Habitat– Tropics and Coastal NW & NE North America
Sphenophytaa.k.a….
Snake Grass!!!
Sphenophyta (Horsetails, Scouring rushes)
• Silica deposits in epidermal cells of stem, used for scouring pots & pans
• Structure– 4-15 feet tall– Whorled branches– Tiny scale-like leaves – microphylls whorled
at nodes or joints– Photosynthetic stem with stomata and hollow,
central core
Sphenophyta
• Reproduction – – Fragmentation – asexual– Strobili produce spores with elaters (prevent
spores from sticking together and aid in spores dispersal)
– Gametophyte reduced, sporophyte visible
Sphenophyta
• History & uses– Food for humans & animals – can be dried &
ground into flour– Medicine – diuretic, antacid, TB, parasites,
gonorrhea– Silica – scouring, polishing, sharpening
Pterophyta“The ferns”
• Structure – – Sizes from 1 cm floating species to tropical 85
ft ferns
Pterophyta“The ferns”
• Structure continued…– Fern leaves – “megaphyll” –
dissected, multiple veins, very feathery
• Immature fronds called “fiddleheads”
Pterophyta“The ferns”
• Structure continued…– Stems arise from horizontal rhizomes– Adventitious roots also arise from rhizomes
Pterophyta“The ferns”
• Reproduction– Sorus – cluster of sporangia on underside of
frond; sporophyte phase
Pterophyta“The ferns”
• Reproduction continued…– Prothalus (Irish valentine) – green heart
shaped gametophyte– Small, 5-6 mm can be seen without
microscope, but generally no bigger than .25 inches
– One cell thick with rhizoids underneath surface
– Antheridium & archegonium produced on upper surface
– Spores develop from archegonium after fertilization, becomes the “fiddlehead”
Pterophyta“The ferns”
• History & uses – – House plants, outdoor ornamentals– Fern bark used in growing rare orchids– In tropics, used for clothing, shelter, baskets– Rhizome used as a vegetable– Medicine – coughs, colds, parasites,
toothaches, bleeding
Alternation of Generations