LAB #3
CLASS BRYOPSIDA
By the end of the term you are required to know a number of bryophytes
by sight. Organisms presented in lab as part of the exercises and as special
features (the Bryo du Jour), as well as common bryophytes we find on fieldtrips
will also be fair game. You will get plenty of practice playing the “Name that
Bryo” game. As the term progresses images of habitat, habit, and structure will
be added to the Public Biology 321 website/blog.
As we work through the bryological material we will also identify
interactions with other organisms. There are many protists, fungi, and insects
that make bryophytes their home! Use the Appendix, page v to record your
observations.
Class Bryopsida
http://blogs.ubc.ca/biology321/?page_id=70
Terms to Know:
antheridium
archegonium
attenuate
cordate
decurrent
diplolepideous
endostome
exostome
haplolepidous
lamina
multiseriate
multistratose
neck
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neck canal
papilla
paraphyllia
paraphyses
perigonium
pinnate
pleurocarpous
protonema
squarrose
uniseriate
unistratose
venter
LAB #3A
CLASS BRYOPSIDA
1. Protonema
Examine the demonstration sample of protonema on soil. It forms a tight
green mat. The protonema in the Petri dish was grown from spores in culture
(similar to what you did in last day’s lab).
Take a sample from the Petri dish and make a slide. Refer to your
“Microscope Use” hand-out to set up your compound microscope in Kohler
(instructors will help if you have never done this).
Examine the protonema. Refer to your lecture notes and describe/draw
the general structure.
Explain the benefit to having an extensive protonematal stage?
When would it not be advantageous?
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2. Plagiomnium insigne
http://blogs.ubc.ca/biology321/?page_id=516
(Fig. 3-2, Schofield pages 210-211)
On our fieldtrip we found this moss growing in a lawn under street trees.
You will also find it in Pacific Spirit and Stanley Park along shaded trails and at
the base of big-leaf maples (Acer macrophyllum)
Gametophyte Structure
Examine the gametophyte. Note the spiral arrangement of the leaves and
the distribution of rhizoids. Remove some rhizoids and make a slide. How do
they compare with the rhizoids you observed in Dicranum scoparium in Lab 1? If
your diagram from the first lab is difficult to interpret you should draw the rhizoids
of Plagiomnium and indicate the oblique (diagonal) cross walls.
Remove leaves from a shoot and make a cross-section through the stem.
Examine it with the compound microscope. Make a sketch of the section and
label. Is there a conducting strand?
Plagiomnium insigne has very large leaves. They are decurrent (the leaf
base extends down the stem below where the middle part of the leaf is attached).
Make a wet mount of a leaf and examine it with the dissection microscope.
Describe the main features of the leaf.
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Examine the leaf with the compound microscope. Draw a tooth to show
the arrangement of cells within the structure, the leaf margin, and the cells of the
blade.
Make a cross-section through the leaf. Note that the blade (lamina) is
unistratose, Which part is multistratose?
Examine a portion of the section through the costa. There is remarkable
differentiation of cells in the costa, including stereids (thick-walled, elongate
fiber-like cells) and a central strand of conducting cells. Draw a portion of the
leaf section through the costa. Label.
Archegonial Plants:
Note the plants with immature sporophytes. The seta elongates prior to
sporangial development. The calyptra is like a little hat on the tip of the
sporophyte. Explain the origin of calyptrae. What ploidy are they?
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Antheridia Plants:
Note the plants with splash cup perigonia that contain paraphyses and
antheridia.
Place a drop of water on a microscope slide on the stage of the dissecting
microscope. Tease out the contents of the perigonium into the water. Spread
the material apart and add a cover slip. Examine with the dissecting microscope.
Note the uniseriate paraphyses and the sac-like antheridia. Sketch.
Examine the prepared slide of a longitudinal section of “Mnium” through
the perigonium. Identify the antheridia and paraphyses. Note that there is no
evidence of an apical cell; it has been “used up” during differentiation of the
perigonium.
Label Fig. 3-2 with as many structures as you can. Include ploidy for all labeled
structures.
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Fig. 3-2 Plagiomnium insigne
3. Rhizomnium glabrescens (Fig. 3-3)
http://blogs.ubc.ca/biology321/?page_id=514
Archegonial Plants:
Like its name indicates this moss has lots of rhizoids! In Pacific Spirit Park
we found it on the bark of an overturned tree. You will also find it on rotting
wood, soil and rocks in shady woodlands.
This acrocarpous moss has a nodding sporangium. A calyptra should be
present on most sporangia. Rhizoids are at the stem base and the leaves are
elliptic. Label Fig 3-3 to indicate the components of the gametophyte and
sporophyte.
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Remove a few leaves and examine microscopically (wet mount and crosssections). Compare the leaf structure of Rhizomnium with Plagiomnium.
Examine the female plants. Pull a sporophyte from a gametophyte;
archegonia and paraphyses (sterile, uniseriate structures) should remain
attached near the foot (which often remains attached to the sporophyte). Find at
least one archegonium with the dissecting scope and then inspect it more closely
with the compound scope. Sketch.
Pull off the calyptra (if present) and identify the parts of the sporophyte.
Examine the prepared slide of the longitudinal section through the sporangium of
“Mnium”. Note the columella. What is its function? Sketch and label with the
following terms:.columella, operculum, peristome teeth, seta, sporangial jacket,
sporangium.
Antheridial Plant:
The antheridial plant is similar to Plagiomnium; the perigonial head
consists of flaring rosette of perigonial leaves that resemble petals of a flower,
surrounding a dark cluster of paraphyses and antheridia. Explain how sperm is
dispersed in these plants.
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Fig. 3-3 Rhizomnium glabrescens
If you were walking in the woods and came upon Rhizomnium
glabrescens and Plagiomnium insigne, what features would you look for to
distinguish between them?
4. Name that Bryo Game / Keying Practice
You need to recognize these bryophytes by sight. The list is posted on
the website and updated every couple of weeks (Bryos to Know). Do you
recognize the bryophytes on display? The names are revealed on the underside
of the cards if you don’t know them yet.
For the remainder of this lab try your hand using the key (Schofield’s Key
to Some Common Mosses of British Columbia)…..even if you know the identity
of the moss you will get practice at using the key. Look at Appendix page v for
some amendments to your key.
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LAB #3B
CLASS BRYOPSIDA
4. Claopodium crispifolium (Fig. 3-4)
http://blogs.ubc.ca/biology321/?page_id=518
The specimens in lab were collected from the base of a big-leaf maple
(Acer macrophyllum). Claopodium crispifolium also occurs on rocks and
boulders.
Claopodium crispifolium is pleurocarpous, i.e. the sporophytes are on
lateral branches that bear perichaetia, while the apex of the shoot exhibits
indeterminate growth. Branching is pinnate and in a single plane. Tease out a
branch system bearing sporophytes. Calyptrae are present on most sporophytes.
Examine the sporophyte with the dissecting microscope. Note that the seta is
papillose.
The light green branch tips help to identify this species in the field.
Remove a few leaves from the stem or branches and place them in a drop of
water on a microscope slide. Examine with the compound microscope. Does
the leaf have a costa? The leaf is broadly heart-shaped (cordate). The apex
has an attenuate point (gradually tapering to a long slender point). Each leaf cell
bears a single papilla, best observed in profile on a curved over portion of the
leaf, or by focusing up and down to view a shiny dot in the middle of each cell.
SKETCH a cell with a papilla.
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Fig. 3-4 Claopodium crispifolium
5. (a) Unknown #1 (Key after you have examined the material)
These samples were collected from an overturned tree in a coniferous
forest. Before you key, take a close look at the sample and identify the main
features. Is this moss acrocarpous or pleurocarpous? Describe the leaf
arrangement and their orientation relative to the stem.
Examine a leaf with the compound microscope. Is there a costa? Does it
have a bordered margin? Is the margin toothed? Are the alar cells different from
other cells of the lamina? Draw and label.
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Examine the sporophytes. There should be immature as well as mature
ones. Draw an immature sporophyte with and without a calyptra.
Examine a dehisced sporangium with the dissecting scope. Draw the
sporangium and include the peristome teeth. There are two rows of peristome
teeth (endostome=inner row and exostome=outer row of teeth). Make a slide of
the peristome teeth and examine the two sets of teeth. Distinguish the
endostomal and exostomal teeth.
Key to Species: ___ à ___à ___à ___à ___à ___à ___à ___à ___à ___à ___
à ___à ___à ___à ___à ___à ___à ___à ___à___ à ___à ___à ___à
___à ___à ___à ___à ___à___ à ___à ___à ___à ___à ___à ___à ___à
___à___ à ___à ___à ___à ___à ___à ___à ___à _
__________________________________
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5. (b) Unknown #2 (Key after you have examined the material)
Observations/Drawings: Describe this moss. Find paraphyllia (filamentous
structures between the leaves). What is their function?
Key to Species: ___ à ___à ___à ___à ___à ___à ___à ___à ___à ___à ___
à ___à ___à ___à ___à ___à ___à ___à ___à___ à ___à ___à ___à
___à ___à ___à ___à ___à___ à ___à ___à ___à ___à ___à ___à ___à
___à___ à ___à ___à ___à ___à ___à ___à ___à _
__________________________________
6. Rhytidiadelphus
There are three Rhytidiadelphus species common to our area. The genus
name reflects its similarity to Rhytidium.
Rhytidiadelphus triquetrus
(electrified cat tail moss)
http://blogs.ubc.ca/biology321/?page_id=524
This moss can be found in various locations in the lower mainland, most
commonly in coniferous forests. It gets its common name from the orientation of
the leaves at the branch tips. Remove several leaves of the main stem and
examine. Note the longitudinal pleats and double costa (be sure to distinguish
the pleats from the costae). The costae extend about 3/4 the length of the leaf.
Margins of the leaf bear tiny teeth. Sketch a leaf outline, showing pleats, costae
and marginal teeth.
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The other two members of this genus are more common in our area (you
saw them on Fiedltrip #1). Rhytidiadelphus loreus is a woodland species. R.
squarrosus is often found in lawns (and considered a weed). Use the glossary in
your key to find out what the specific epithet (squarrosus) refers to.
Compare and contrast the characteristics of the three species of
Rhytidiadelphus. What are key features you would use to identify and distinguish
them in the field?
Rhytidiadelphus loreus
http://blogs.ubc.ca/biology321/?page_id=526
R. squarrosus
http://blogs.ubc.ca/biology321/?page_id=983
7. Key that Moss
Observations/Drawings:
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Key to Species: ___ à ___à ___à ___à ___à ___à ___à ___à ___à ___à ___
à ___à ___à ___à ___à ___à ___à ___à ___à___ à ___à ___à ___à
___à ___à ___à ___à ___à___ à ___à ___à ___à ___à ___à ___à ___à
___à___ à ___à ___à ___à ___à ___à ___à ___à _
__________________________________
As Time Permits for Practice
Key to Species: ___ à ___à ___à ___à ___à ___à ___à ___à ___à ___à ___
à ___à ___à ___à ___à ___à ___à ___à ___à___ à ___à ___à ___à
___à ___à ___à ___à ___à___ à ___à ___à ___à ___à ___à ___à ___à
___à___ à ___à ___à ___à ___à ___à ___à ___à _
__________________________________
Key to Species: ___ à ___à ___à ___à ___à ___à ___à ___à ___à ___à ___
à ___à ___à ___à ___à ___à ___à ___à ___à___ à ___à ___à ___à
___à ___à ___à ___à ___à___ à ___à ___à ___à ___à ___à ___à ___à
___à___ à ___à ___à ___à ___à ___à ___à ___à _
__________________________________
Key to Species: ___ à ___à ___à ___à ___à ___à ___à ___à ___à ___à ___
à ___à ___à ___à ___à ___à ___à ___à ___à___ à ___à ___à ___à
___à ___à ___à ___à ___à___ à ___à ___à ___à ___à ___à ___à ___à
___à___ à ___à ___à ___à ___à ___à ___à ___à _
__________________________________
Key to Species: ___ à ___à ___à ___à ___à ___à ___à ___à ___à ___à ___
à ___à ___à ___à ___à ___à ___à ___à ___à___ à ___à ___à ___à
___à ___à ___à ___à ___à___ à ___à ___à ___à ___à ___à ___à ___à
___à___ à ___à ___à ___à ___à ___à ___à ___à _
__________________________________
Key to Species: ___ à ___à ___à ___à ___à ___à ___à ___à ___à ___à ___
à ___à ___à ___à ___à ___à ___à ___à ___à___ à ___à ___à ___à
___à ___à ___à ___à ___à___ à ___à ___à ___à ___à ___à ___à ___à
___à___ à ___à ___à ___à ___à ___à ___à ___à _
__________________________________
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