Transcript BIO605 Lecture # 13 File

School of Sciences, Lautoka Campus
BIO509 Botany Lecture 13 : Phylum
Lycophyta (club mosses, spike mosses and
quillworts).
Stems of plants are covered with
microphylls that are photosynthetic.
Sometimes called ground pine.
Sporangia on or in the axils of
sporophylls on strobili.
Heterosporous & homosporous.
Distribution- global.
Habitat- forest floors, deserts, aquatic.
~1,200 species.
Examples- Lycopodium, Selaginella,
Isoetes.
Lycopodium
• Lycopodium – ground pines
(resemble Christmas trees with
cones)
• Grow on forest floors
• Stems either simple or
branched
• Less than 30 cm tall
• Leaves may be whorled or in
tight spiral
• Adventious roots and can
produce root hairs which
develop along the rhizomes
• Fiji: 3
genera, 14
species
(“lewa nini”)
Life cycle of Lycopodium - homosporous
Selagenella – spike Mosses
• Sporophytes are larger than
• the Lycopodium.
• Approximately 700 species,
7 species in Fiji)
• Especially abundant in the
tropics.
• More freely branched
• Leaves have an extra
appendage or tongue called
ligule on the upper surface
near the base.
• They are heterosporous.
Isoetes - Quiltworts
Isoetes – Quiltworts
• Aquatic or seasonally dry ponds.
• Leaves (microphylls) are slightly spoon
shaped at the base and arranged
spirally on a stubby stem.
• Ligules occur towards the leaf base.
• Corm is short, fleshy underground
stem.
• Reproduction is similar to spike
mosses but lacks strobili.
• Heterosporous, both types of
sporangia produced at the base of the
leaves.
Human and Ecological Relevance of Club
Mosses and Quiltworts
• Are of little economic importance
• Large members of club moss produce flash of light
when ignited and this was used to manufacture
explosives and photographic flash.
• Used as medicine to treat urinary and stomach
disorders, reduce fevers.
• Native Americans used club moss as a talcum powder
for babies and to treat bleeding.
• Club mosses and spike mosses have been used as
ornamental plants.
• Quillwort corms have been eaten by animals and
humans.
Novelty stores sell a species of
spike moss as resurrection plants.
– Some species of Selaginella shrivel
when dry, then grow again with
water
Phylum Equisetophyta (Sphenophyta)–
the Horsetails and Scouring Rushes.
Phylum Equisetophyta – the Horsetails and
Scouring Rushes.
• Widespread in moist or damp places.
• Equisetum (horsetails, 25 species, 1 in Fiji).
• Sporophytes have ribbed stems containing
silica deposits and whorled scalelike
microphylls that lack chlorophyll.
• Two forms – branched and unbranched.
Branched
This is commonly called horse tail because the
branches look a little like horse tail.
Un-branched
• Commonly called scouring
rushes because they inner
walls of the epidermal cells
have silica deposits which
make it excellent scouring
materials for dirty metal
pots and pans.
• Used extensively by native
Americans
• Stems conspicuously jointed, and
ribbed.
• Rough texture (siliceous deposits).
• Microphylls whorled and arise at
nodes.
• Most photosynthesis takes place in
stems.
• Have obvious nodes and internodes.
• There are numerous stomatal pores in
the stems.
• Xylem and phloem are present in the
stem.
• The aerial stems develop form
horizontal rhizomes, which also have
regular nodes, internodes and ribs.
• In some species
adventitious
roots may be
present and may
form extensive
branching below
the surface.
Lifecycle of a Equistem - homosporous
Human and Ecological Relevance of Horsetails
and Scouring Rushes
• The Romans boiled strobilis of horsetails or
fried them after mixing them with flour.
• Native Americans peeled off the rough
epidermis of young stems and ate the inner
parts raw or boiled.
• Also, the rhizomes of giant horsetails were
cooked for food.
• Cows, goats, muskrats, bears and geese ate
horsetails
Human and Ecological Relevance of Horsetails
and Scouring Rushes
• Horsetails were thought to increase red blood
cells.
• In some cases they were used as diuretic to
increase the flow of urine).
• Used for the treatment of diseases suchas
gonorrhea and TB.
• Burnt stems were used to cure mouth sours.
• Used for cleaning pots, polishing brass and
hardwood furniture
Questions??