I.
Demonstrations. This lab will cover all the monocots. Look at these
in as much detail as you want, but be sure to identify and understand the
characters indicated on the sheet next to each demonstration. Refer to your
lecture handouts, Plant Systematics [T], and the Zomlefer [Z] resource
for more details.
1. Alismatales:
Anthurium, Aglaonema, Spathiphyllum (Araceae)
(pp. 160-163 [T], 301-303 [Z])
A primitive monocot group; find the spathe and spadix in
the plants shown here.
The inflorescence of Araceae are usually composed of unisexual flowers.
Examine the spadices and determine where are located the female, male,
and (possibly) neuter floral regions.
2. Alismatales:
Pistia (Araceae
- water lettuce) (pp. 160-163 [T], 301-303 [Z])
Once considered the "missing link" between terrestrial Araceae
and the aquatic Lemnaceae, Pistia is now clearly just another aquatic
Araceae.
Tear a small piece of one leaf; do you see the specialized tissue that
permit water flotation? This tissue is composed of aerenchyma.
Look carefully in between the smallest leaves, what do you see in there
(be specific)? . Once you have figured that out, look at the illustration
on the right to verify your answer.
3. Alismatales:
Spirodela, Lemna and Wolffia (Lemnaceae
- duckweeds; now placed in Araceae) (pp. 160-163 [T], 301-303 [Z])
These are the smallest Angiosperms. None are in flower, but note the vegetative
features under the microscope. The entire plant consists of a tiny leaf
and little rootlets. The plants reproduce mostly vegetatively and flowers
are rare.
4. Lilioids:
Paphiopedellum and Oncidium (Orchidaceae
- orchids) (pp. 171-177 [T], 293-297 [Z])
Paphiopedellum belongs to the subfamily Cypripedioideae (lady slippers).
- calyx consists of 3 sepals (connation is occurring!)
- one of the 3 petals is modified to form a pouch like labellum
- this subfamily has 2 stamens and does not have true pollinia
- note the inferior ovary; how many carpels would you expect to be present?
Oncidium belongs to the more derived subfamily Orchidoideae
- find the perianth parts; are they different than in the lady slippers?
- orchids are considered up-side-down flowers or resupinate, as the labellum
is morphologically the topmost petal. Do you see any evidence of this
twisting?
- this subfamily has only one stamen with generally one or two pollinia.
- the fertile stamen and sterile stamens are fused to the style and stigmas
to form a column; can you find this structure? A beak or rostellum is
modified from the one sterile stigma; locate this structure.
5. Commelinids:
Avena (Poaceae
or Gramineae - oats) (pp. 213-219 [T], 350-356 [Z])
Grasses, and their relatives the sedges, are the most advanced commelinoids
and also the most reduced florally.
Use your lecture handout (with lecture outlines) illustrating the makeup
of grass florets (the flower) and spikelets (the inflorescence) to understand
and recognize the basic parts of the grass flower and inflorescence [a
copy available to your right].
In the dissected oats spikelet, find the two bracts called glumes enclosing
each set of florets. How many florets in each spikelet? Find the two bracts
called lemma and palea that enclose each individual floret. Locate the
stamens and ovary. Are they present in each floret? If you can, also locate
the lodicules.
II. Additional representatives
of these and other families are placed around the room. As time permits,
examine these plants and especially note the floral structures. You will
not be required to know these plants; they are simply provided to illustrate
additional members of these families. AL = Alismatales, L
= Lilioid, C
= Commelinid
1. Araceae
[AL]: Anthurium, Alocasia, Aglaonema, Spathiphyllum, Colocasia
(taro)
2. Aponogetonaceae
[AL]: Aponogeton madagascariensis (water hawthorn, lace
plant)
3. Potamogetonaceae
[AL]: Potamogeton (pond weed)
4. Liliaceae
(in broad sense) [L]: Amaryllis [Alliaceae], Allium
([Alliaceae - onion), Asparagus [Asparagaceae] Aloe [Xanthorrhoeaceae],
Agave [Xanthorrhoeaceae], Lilium (lily)
5. Iridaceae
[L]: Iris (iris), Gladiolus, Freesia
6. Dioscoreaceae
[L]: Dioscorea (yam)
7. Orchidaceae
[L]: Dendrobium,
Dortitis, Epidendrum, Phalenopsis.
8. Arecaceae
[C]:
(Palmae): Phoenix (date palm).
9. Zingiberaceae
[C]:
Hedychium, Zingiber (ginger).
10. Costaceae
[C]:
Costus.
11. Marantaceae
[C]:
Maranta (prayer plant).
12. Cannaceae
[C]:
Canna.
13. Bromeliaceae
[C]:
Ananas (pineapple), Billbergia, Brocchinia, Cryptanthus,
Navia, Neoregellia, Vriesea.
14. Commelinaceae
[C]:
Dichorisandra (blue ginger), Rhoeo, Setcresea, Zebrina.
15. Pontederiaceae
[C]:
Eichhornia (water hyacinth).
16. Cyperaceae
[C]:
Cyperus (dwarf papyrus), Scirpus (bulrush).
17. Poaceae
[C]:
Lithachne (bamboo), Pharus (bamboo), Oryza (rice),
Zea (corn), Hordeum (barley), Agrostis, Andropogon,
Digitaria, Panicum, Pennisetum, Rhynchelytrum.
III.
14 genera of Wisconsin plants to be able to identify on site. AL
= Alismatales, L = Lilioid, C = Commelinid
1. Sagittaria
(Alismataceae
- arrowhead) AL
2. Arisaema (Araceae
- jack-in-the pulpit) AL
3. Erythronium
(Liliaceae
- trout lily, dog-toothed violet) L
4. Trillium (Melianthaceae - trillium) L
5. Polygonatum
(Asparagaceae - Solomon's seal) L
6. Maianthemum (Asparagaceae - wild lily-of-the-valley) L
7. Smilax (Smilacaceae
- catbriar, greenbriar) L
8. Iris (Iridaceae
- iris, blue flag) L
9. Cypripedium
(Orchidaceae
- lady slipper) L
10. Tradescantia
(Commelinaceae
- spiderwort) C
11. Typha (Typhaceae
- cattail) C
12. Carex (Cyperaceae
- sedge) C
13. Andropogon
(Poaceae
- bluestem, turkeyfoot) C
14. Bouteloua (Poaceae
- grama grass) C
IV.
Check your plant collections for any specimens that belong to these groups
of monocots and key them out using Gleason and Cronquist if you have not
done so already.
