Week 6 Laboratory
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This lab will cover the Caryophyllids – the first of the three major groups of core eudicots. This group contains only the order Caryophyllales, but the order contains a diversity of plants ranging from carnivores like the sundew family, stem-succulent, desert specialists like the cactus family, salt loving halophytes like the amaranth family, to temperate leaf-succulents like the spring beauty family. Besides the obvious adaptations to xeric conditions, salt, and low nutrients, the majority of families lack petals or have petals derived from stamens. The laboratory is designed so that you become familiar with this order by dissecting flowers of representative members, observing demonstration materials of other members, and by learning to identify local genera (and knowing genus, family, and common name). Two species are also provided for practice in using a genus key from the Field Manual of Michigan Flora (Voss & Reznicek).
Refer to pp. 295-312 in Plant Systematics, 2nd ed., and pp.54-69 in Zomlefer resource for information on this group of angiosperms. Also, please visit the University of Wisconsin Plant Systematics Collection homepage that will describe these and other families in some detail and are linked to images: [http://botit.botany.wisc.edu/courses/systematics/index.html].
I. Detailed floral dissections on frozen/pickled flowers. Include these in your laboratory notebook with illustrations and labeled parts. Refer to Field Manual of Michigan Flora [M] for descriptions of the species as needed and to Plant Systematics, 2nd ed. [T] and Zomlefer [Z] for descriptions and drawings of the families.
1. Phytolacca americana (Phytolaccaceae - pokeweed, pokeberry) (pp. 741 [M], 299 [T], 61-63 [Z])
Phytolacca has a very simple type of inflorescence, what kind is it?
The gynoecium is modified from the more typical placentation type seen in the subclass; what placentation does it exhibit? How many carpels are there? How many ovules in each? What kind of fruit is produced?
Take a look at the demonstration jar of another species of Phytolacca discovered in Olin Park. Compare the type of gynoecium; what is different about this species?
Give a floral formula for Phytolacca.
2. Saponaria officinalis (Caryophyllaceae - soapwort, bouncing-bet) (pp. 537 [M], 305 [T], 54-56 [Z])
Notice the inflorescence of Saponaria. It is typical for the family. What kind is it?
The calyx and/or corolla show some modifications; can you list them? Find the blade and claw of the corolla.
Saponaria possesses the typical placentation type of the group, what is it? What kind of fruit is produced?
Provide a floral formula for Saponaria.
II. Demonstration floral dissections. 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 floral dissection. Include your comments and answers below. Many of these also will be found in Field Manual of Michigan Flora [M], or Plant Systematics [T], or Zomlefer [Z].
1. Portulaca oleracea (Portulacaceae - purslane) (pp. 779-780 [M], 299 [T], 56-58 [Z])
2. Chenopodium album (Amaranthaceae - lamb's quarters) (pp. 313-314 [M], 301 [T] - previously placed under Chenopodiaceae, 65-67 [Z])
3. Amaranthus retroflexus (Amaranthaceae - pigweed) (pp. 308-311 [M], 301 [T], 67-69 [Z])
4. Persicaria pensylvanica (Polygonaceae - smartweed) (pp. 773 [M], 309 [T], 86-87 [Z])
III. 11 genera of Wisconsin plants to be able to identify on site (* = not presently found in Wisconsin).
Herbarium specimens of these plants will be marked to genus (and to family) and will be kept in the laboratory until the next laboratory exam when you will be tested on them. Images of each of these required genera are provided with each specimen and on the course webpage for this lab. Other images are available on the Michigan Flora webpage at the University of Michigan Herbarium website and the Wisflora webpage at the Wisconsin State Herbarium. Use the Field Manual of Michigan Flora (Voss & Reznicek) [copies of the book are available] as much as possible to understand why each genus is different from other genera in the same family. This will help you not only to identify the plants to genus and family, but might be necessary as we will test you with different herbarium sheets, images, or live representatives of these plants!
1. Froelichia (Amaranthaceae - cottonseed)
2. Amaranthus (Amaranthaceae - pigweed)
3. Opuntia (Cactaceae - prickly pear)
4. Phytolacca (Phytolaccaceae - pokeweed)
5. Chenopodium (Amaranthaceae [previously Chenopodiaceae] - lamb's quarters)
6. Saponaria (Caryophyllaceae - bouncing bet, soapwort)
7. Silene (Caryophyllaceae - catchfly, campion)
8. Arenaria (Caryophyllaceae - sandwort)
9. Portulaca (Portulacaceae - purslane)
10. Claytonia (Montiaceae [previously Portulacaceae] - spring beauty)
11. Persicaria (Polygonaceae - smartweed)
IV. 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.
1. Rivinia humilis (Phytolaccaceae - rouge plant)
2. Talinum paniculatum (Talinaceae - jewels of opar)
3. Portulaca grandiflora (Portulacaceae - rose moss)
4. Gypsophila elegans (Caryophyllaceae - baby's breath)
5. Dianthus chinensis (Caryophyllaceae - rainbow pink)
6. Dianthus barbatus (Caryophyllaceae - sweet William)
7. Mirabilis nyctagineus (Nyctaginaceae - wild four-o'clock)
8. Bouganvillea glabra (Nyctaginaceae - bouganvillea)
9. Pisonia umbellifera (Nyctaginaceae - para para)
10. Cactaceae spp. (cacti) - look for examples of the three subfamilies
11. Didiereaceae - endemic to Madagascar (octopus plant and others)
12. Lithops (Aizoaceae -- living stones)
13. Kochia scoparius (Amaranthaceae) - summer cypress)
14. Gomphrena globosa (Amaranthaceae - globe amaranth)
15. Celosia cristata (Amaranthaceae - feather amaranth, cockscomb)
16. Amaranthus caudatus (Amaranthaceae - loves lies bleeding)
17. Nepenthes (Nepenthaceae - pitcher plants)
18. Drosera (Droseraceae - sundews)
19. Dionaea (Droseraceae - Venus flytrap)
20. Fagophyrum esculentum (Polygonaceae - buckwheat)
V. Key these two plant specimens to species using the Field Manual of Michigan Flora (Voss & Reznicek) [copies of the book are available]. This kind of question might well be on a laboratory exam. To check your answer or help when stuck in the key, the correct identification is written on the bottom of the card with each set of specimens.
1. Cerastium sp. (p. 530)
2. Persicaria sp. (p. 770)