Bryophyta Flashcards
Class Sphagnopsida
-common name
Class Bryopsida
-common name
-peat mosses
-true misses
Class Sphagnopsida
Order Sphagnales
-habitat
-morphology
-how do they grow
-wet acid bogs and forests in cool and cold parts of the world
-dense and deep cushions and mats
-individual plants grow for many years and may become up to 1 meter in length. Old parts die as the top grows ever upwards. The dead parts only partially decay due to acidic properties.
Peat
Accumulations of dead plants that may be meters deep and are often harvested for fuel or for soil additives for water conservation
Class Sphagnopsida
Order Sphagnales
Gametophytes arise from …..
Protonemata - plate like
Stems of peat moss gametophytes bear clusters of five branches at each node. Branches are highly tufted near the stem apex where they from a mop/-like head.
Their leaves lack costa (midrib) and mature plants lack rhizoids
Class Sphagnopsida
Leaves and stems
Considerable cellular differentiation within the leaves and stems.
Large, hollow, dead cells (hyaline cells) in the leaves have pores that allow direct entry by water.
Between water - storing hyaline cells are rows of small, living, thick-walled cells with many chloroplasts called chlorophyllous cells
Anthocyanain pigment gives off purplish tinge
Types of branches in Class Sphagnopsida
Lateral branches: stuck outwards from the side of the stem
Pendulous branches: hang down, coiled
Class Sphagnopsida
Water is wicked up between the pendulous branches and the outside surfaces of the main stem by a ……
Capillary movement
The water storing capacity of _______ cells together with the wicking effect of the _______, gives sphagnum a tremendous ________ capacity
Hyaline
Pendulous branches
Water holding
Capitulum
Reproductive branches
Hyaline cells
Large, transparent, hollow water storing cells
Class Sphagnopsida
Order Sphagnales
Stem tissue divided into 2 regions….
- Inner pith-> photosynthesis and storage
- Outer cortical layer of larger, usually dead cells->water absorption and protection
Perichaetial leaves
Surround the archegonia and later, the base of the sporophyte
How are sporophytes of Class Sphagnopsida distinctive
-capsules are nearly spherical and are raised on stalks called Pseudopodia are are part of the gametophyte
-sporophyte is a very short stalk
-spore discharge: internal tissues of the capsules shrink as they mature, resulting in gas-filled interior chambers with high pressure. Further contraction of the maturing capsule results in the operculum being blown off and the escaping gas Carrie’s a cloud of spores out of the capsule
Archegonia and antheridia in Class Sphagnopsida are present but are hidden in the protective ……. Leaves
Perichaetial
The gametophyte phases of all losses pass through two distinct developmental stages:
The protonema stage: arises from the germinated spore
The leafy gametophyte stage: develops from buds on the protonema
In true mosses, the protonema is a _______, branching filament which superficially resembles …….
Uniseriate (cells occurs in a tingle filament)
Filamentous green algae
Some branches of the protonema penetrate the substrate and lose their chloroplasts, these are known as….
Rhizoids
Class Bryopsida
Gametophyte characteristics
-leafy and usually upright and range from a few millimetres to 50 cm or more.
-multicellular rhizoids
-leaves are one cell layer thick (except at costa)
-stems lack conducting cells (exception)
Exception to stems without conducting cells in Class Bryopsida
Polytrichium sp. and a few related genera have a central stand of elongate cells that play a role in conduction but are not sufficiently specialized to be considered fully functional vascular tissue
Lamellae
Photosynthetic cells that form filaments along the leaf
Two common growth patterns amongst the mosses
- Acrocarpus forms or Cushion mosses: erect, more or less unbranched gametophytes and bear terminally attached sporophytes
- Pleurocarpus of feather mosses: plants are much-branched and are creeping with laterally borne sporophytes
Life history of Class Bryopsida
Some genera are unisexual (dioecious), whereas in others both archegonia and antheridia are produced by the same plant (monoecious) m
Gametangia are produced by ……..
Class Bryopsida
By mature leafy gametophytes at the tips of the main axis, or on lateral branches
Class Bryopsida
Sporophyte characteristics
-small compared to gametophyte
-each consists of a foot embedded in the tissues of the gametophyte, a seta or stalk that elevated the capsule above the gametophytes.
-capable of photosynthesis while still early in their development
-gradually lose ability to photosynthesis and turn brown
Difference between liverworts and bryophytes in terms of nutrition
Sporophytes of bryophytes are capable of photosynthesis while still early in their development and therefore are much less dependent on the gametophytes for nutrition than liverworts.
Spore discharge of class Bryopsida
Upon maturity, a lid-like operculum bursts off the capsule and allows the spores to be discharged.
The loss of the operculum reveals a ring of ……
Peristome teeth that surround the opening of the operculum.
Peristome plays a role in regulating spore discharge and is characteristic in class Bryopsida but not in class Sphagnopsida
Class Bryopsida
Order Polytrichales
Common name
Characteristics
Hair mosses
-acrocarpus gametophyte
-leaves with well/developed costae
-upper surface covered by parallel ridges known as lamellae.
-stem differentiated into several types of tissues that include support tissue that resembles sclerenchyma and the above central cylinder that resembles the conducting tissue of vascular plants
Class Bryopsida
Order Polytrichales
Cortex:
Central cylinder:
Living cells
Central cylinder:
-hydroids: dead cells to conduct water (similar to xylem)
-leptoids: cells to conduct sugars
Class Bryopsida
Order Polytrichales
Life cycle
-male gametophytes have….
-female gametophytes have…
Antheridial cups
Female gametophytes with young and mature sporophytes
Class Bryopsida
Order Eubryales
Characteristics
-gametophytes and sporophytes are less complex than those of order Polytrichales
-leaves are simple
-classified into 2 groups according to habitat and growth:
- Acrocarpus mosses: upright and bear sporophytes at the apices of their stems
2.Pleurocarpus mosses: creeping and bear sporophytes on lateral branches
Two types of abundant feather mosses in boreal forests of Manitoba that form mycorrhizal relationships with fungi and with coniferous trees
Red-stem feather moss
-branching reddish horizontal stems covered by minute leaves. Sporophytes attach laterally on main stems, not at
Stem tips
Stair step moss
-smaller leaves and laterally places sporophytes if present. Grows in increments like steps.
Vegetative reproduction is so successful that sexual reproduction is scarce
