Lab 3: Vegetative characters

This lab was designed to teach you some useful vegetative characters for plant identification and that are really important for the rest of the class.  You can read more about vegetative characters on Chapter 4 of the text book.  At the bottom of each picture you are going to have the scientific names of the plants that you saw in lab.  It is a good exercise to get familiarized with the names and also with this system of assigning names to plants.
The lab had examples of:

I. Duration: we did not have examples of "duration" in class but you can think about seasonality and how is that related to plants, do all plants come back after the winter?

II. Roots function as an anchorage, absorption and storage organ for the plant.  These are different examples of roots that you observed in the lab.

A. Taproots

 

Sida rhombifolia

 Daucus carota

B. Fibrous roots

Megathyrsus maximus (left) & Eleusine indica (right)

  

In this specimen you were able to see two root types: fibrous and adventitious

 

Stenotaphrum secundatum

 C.Adventitious roots

Try to enlarge this picture in your browser and check the roots of this small leafless orchid, do you notice that they are photosynthetic? (green)

Dendrophylax porrectus

 

Clusia sp.

Phyla nodiflora

  D.Aerial  roots

 

Tillandsia recurvata 

Special example: Ipomoea batatas (this is an example of tuberous roots)

III. Stems: they can be aerial or subterranean and divided into nodes, the points at which leaves are borne, and internodes, the areas between the nodes.

A. Rhizomes

Stenotaphrum secundatum

B. Tubers

Solanum tuberosum

C. Corms

Colocasia esculenta, besides the corm, this species also shows rhizomes

D. Bulbs

 

Allium cepa

Important questions: Where are the carbohydrates stored in a corm? bulb?

E.What is the difference between thorns, spines and prickles? What is the function/s of these structures?

Thornes

Citrus trifoliata

Spines- note the green fleshy stem

 Opuntia

Prickles

 Rubus cuneifolius

V. Leaves: they function as photosynthetic organs, generally broad and/or flattened and borne at the nodes of a stem.  In flowerng plants just above the point of attachment of the leaf base or petiole there is an axillary bud.

A. Leaf arrangement.

 Alternate leaves

Prunus caroliniana

Opposite leaves

 

Viburnum odoratissimum

Whorled

Nerium oleander

 

Clerodendrum indicum

B. Parts and features of leaves

 Identify parts of a leaf, leaf venation, leaf margins, apex and base of leaves: In this part of the lab you were asked to identify the following structures in different plant species, you need to be able to distinguish:

Parts:

1. pulvinus 

2. petiole

3. blade

4. stipules

5. leaf axil

6. adaxial and abaxial surfaces

7. compound vs. simple leaf

8. pinnately vs. palmately compound leaf

9. A sessile leaf

We recommend you to use all these pictures to review all of the terms mentioned above

 Cercis canadensis

Check the large stipules present in this plant

Dombeya x cayeuxi

This specimen has  pinnately compound leaves

Carya glabra

Contrast the previous specimen with this one that has palmately compound leaves

Casimiroa edulis

This plant has unifoliolate leaves, this is an example of a compound leaf that has been reduced to a single leaflet, observe carefully the base of the leaf.

Citrus aurantiaca

This is an example of sessile leaves

 

Eucalyptus sp.

Types of leaf venation:

1. Parallel - most of the monocots have parallel leaves

2. pinnate

Carpinus caroliniana

3. Palmate

Liquidambar styraciflua

Leaf variation: the following section tries to show you the diversity of leaf forms. As an exercise try to describe them using the appropriate botanical terms, and make sure that you can identify if leaves are simple, compound, types of margins, shapes of the base and apex. Remember to look at both sides of the leaves (abaxial and adaxial), since some important identification features can be located on one side of the leaf only (hairs, domatia, pellucid dots, etc).

This is an example of lobed leaves, look at the shape, apex, base, venation

Liriodendron tulipifera

The abaxial side of this leaf is white, in botanical/latin terms this is called "glaucus"

Acer rubrum

Look at these pinnately compound leaves

Sapindus emarginata

Check the leaf variation within the same individual

Quercus hemisphaerica

Quercus nigra

Check the crenate leaf margins on this leaf

Ardisia crenata

Pinnately compound leaves

 Pistacia chinensis

Quercus

 How many times compound?

Nandina domestica

Koelreuteria elegans

This plant has compound leaves and also compound stipules, check them out

 Delonix regia

This specimen has peltate scales

Elaeagnus pungens

These are some examples of modified leaves

 Echeveria imbricata

 Nepenthes

Agave

 

Lab 2: Phylogenetics, classification and key building

In class, we used taxa from family Boltaceae to understand morphology as it relates to phylogenetics, classification and key building.  Here are some characters and character states that we described in class:

Boltaceae characters:

1.     Thread: absent (0), present (1)

2.     Point: present (0), absent (1)

3.     Top shape: flat (0), rounded (1)

4.     Length: long (>3cm), short (1)

5.     Screwdriver interface: none (0), Phillips (1), flat (2)

6.     Color: silver (0), blackish, (1), bluish (2)

Map these characters, using the characters states provided, to understand the evolution of these characters.  Where are the synapomorphies? Are any characters homoplasious?

Classifying is both a subjective and objective process.  Remember that named groups must be monophyletic.  Make a classification scheme for the members of the Boltaceae above.  Then make a key to provide a practical way by which the taxa you defined may be easily identified.

Now, use the skills you learned in making a key of Boltaceae to identify the plants in lab:

Match the letter to each plant species next to the jar in the following list, using the key below:

Key:

1. Leaves compound or highly dissected

          2. Veins parallel

                      3. Leaves more than 2m long…Sabal palmetto

                      3. Leaves less than 1m long…Zamia furfuracea

          2. Veins reticulate…Grevillea robusta

1. Leaves simple

          4. Leaves opposite

                      5. Leaves less than 1cm wide…Olea europaea

                      5. Leaves more than 2cm wide…Ligustrum japonicum

          4. Leaves alternate

                      6. Leaves broad and flat…Magnolia grandiflora

                      6. Leaves linear and roundish in cross section

                                  7. Leaves clustered into fascicles, not covered in scales…Pinus palustris

                                  7. Leaves not clustered into fascicles, covered in scales

                                              8. Plants long and dangling with relatively narrow leaves…Tillandsia usneoides

                                              8. Plants short and clumping with relatively large leaves… Tillandsia recurvata

Lab 1: Specialized botanical library, Herbarium and collecting techniques

The first week of lab you visited the FLAS Herbarium located in the Florida Museum of Natural History of the University of Florida that houses one of the biggest collections of Floridian plants.  We would like to encourage you to read read more about the collections that are deposited in this institution and other services and projects in the following link:  http://www.flmnh.ufl.edu/herbarium/

FLAS Herbarium

You were also introduced to important floras and botanical literature available in the FLAS Herbarium that will be very useful in your future botanical projects.  You can browse the FLAS library through the following link: http://www.flmnh.ufl.edu/herbarium/lib

 FLAS library

Floras of the southeastern US that might help you to identify your plants

The herbarium also offers drying and mounting plant facilities.  If you plan to collect plants and process them in a professional way we recommend you to check the following site and use the facilities that FLAS offers: http://www.flmnh.ufl.edu/herbarium/voucher.htm

Plant press available at FLAS herbarium for plant collecting

Plant drier