|About this site||Links||Quiz||Assignment|
|Stems links with descriptions||Stem Structure||Botany - Virtual Library|
|Plant Structure||Plant Morphology||Vegetable Images|
|Plant Images||Bulbs & Rooting Structures Definitions and illustrations||Internet Directory|
|bean- seedling with labels||Plant physiology -|
|DIVERSITY AND ADAPTATIONS|
|Twiner||Tendrils - grape - photo||Thorns Honey Locust|
|Stolons / Runners Grass||Cladode/Cladophyll Asparagus - foliage||Storage Stems - Google|
|Strawberry begonia||Cladophyll of Ruscus cladode||Stem modifications - diagrams|
|Modified stems - Modified stems - Google search engine images|
|BELOW GROUND MODIFICATIONS|
|Bulb l.s. onion||Corm Gladiolus||Tuber Potato|
|Rhizome Iris||Modified stems and roots||Modified stems|
|Bamboo shoot||Asparagus||Sugar cane|
|Garlic, Leek, etc.||Maple sap - The process||Poi (Taro) - Taro- foliage|
|Coleus stem tip||Diagram - tip||apical meristem - Google|
|apical meristem - stem Google||.||.|
|Corn Stem - labels||Corn Stem Vascular bundle||Monocotyledons|
|Vascular elements Zea mays||Corn - How a corn plant develops||Corn- early development diagram|
|apical meristem corn -||images|
|Sunflower x.s. stem||Sunflower - freehand||Sunflower young - labels|
|Sunflower - the stem||Sunflower - t.s.||vascular bundle (stem)|
|Medicago stem labeled||Diagram alfalfa||cells and tissues|
|stem||dicot stem - shoot primary growth||plant tissues and cell types|
|Helianthus - Google results||Sunflower-Flash click part||Slides - t.s. older stem|
free hand sections
I selected links with images and information related closely to the observations described in lab Exercise 4 (Plant Stems) of your botany lab manual. Preview these resources as you prepare for the laboratory exercise and review these resources as you write your lab reports and study for tests.
One section in the beginning of lab samples the diversity of plant stems and a second section illustrates some stems of economic importance. However, emphasis of today's laboratory is external stem structure and internal stem anatomy (tissues and cell types).
Focus your attention on identifying tissues by their location, cell types and characteristic appearance. Visualize how sections of stems would be positioned in the intact stem, and try to relate transverse (c.s.) with longitidinal sections. Learn to distinguish between (1) monocot and dicot stems, (2) young, mature, and woody stems and contrast stems with the roots that you studied last week.
I will allow you to work mostly on your own in this lab period, but I will be available to help you locate or interpret any of the structures mentioned in the laboratory exercise. I will have numerous illustrations from reference books available to assist you in your study of stems. As you make your observations you might quiz yourself by seeing if you would be able to locate the following items and show them to me.
- Bundle Cap
- Leaf gap
- Pith ray
- Sieve plate
- Vessel element showing pore
I. DIVERSITY AND ADAPTATIONS OF STEMS- links to stem types illustrate some of the diversity and adaptations mentioned in the lab manual
II. STEMS OF ECONOMIC PLANTS - STEM CROPS- links to stem types illustrate many of the stem crops mentioned in the lab manual
III. EXTERNAL STRUCTURE OF HERBACEOUS STEMS1. Sunflower - These are the plants you started in lab 1
2. Coleus - one link under shoot tip shows a view of a Coleus plant
3. Corn - you may wish to review the links to corn in lab 1
IV. INTERNAL STEM STRUCTURE
A. Herbaceous Dicot Stems1. Fresh Material - Dye Movement in Sunflower Stem
2. Prepared slides - Herbaceous Stemsa. Sunflower (t.s.) - links illustrate this stem at different magnifications
b. Cucurbita (l.s.) - nice material for studying phloem (bundles have phloem both inside and outside of the xylem
B. Herbaceous Monocot Stem (Zea mays)1. Fresh Material - Corn Stem
2. Prepared Slides - Corn Stem - links show corn stems at various magnifications
V. Record of Cell TypesComplete the table of cell types in the lab manual based on your own observations
VI. Buds, Growing Points of Shoots1. Coleus Stem Tip -- Fresh Material
2. Coleus Stem Tip - Prepared Slide (l.s.) - links show sections of stem tip and apical meristem
Assignment for Laboratory Exercise 4 - Stems
1. Examine the materials on display in the room. These will
include living and preserved plants, prepared slides, wall
charts and illustrations from a variety of books and other
2. Observe the demonstrations which illustrate diversity of
adaptations of stems. Complete Table 4.1 Adaptations of
3. Observe the demonstrations which illustrate selected stems
of economic value. Add your notes and comments to Table 4.2
Stems of Economic Crops.
4. Diagram and label a sunflower shoot (Page 4-7).
5. Complete Table 4.3 Comparison of Stems of Sunflower, Coleus
6. Observe fresh mounts and prepared slides of Sunflower and
Corn and Cucurbita. Label Fig. 4.2 Transverse Section of Sunflower
Stem, 4.3 Vascular Bundle of Sunflower Stem, 4.5 Transverse Section of
Corn Stem, and 4.6 Vascular Bundle of Corn.
7. Draw cell types to complete Table 4.4 Cell Types Found in
8. Sketch and label the appearance of terminal and axillary
buds of Coleus as seen with the dissecting microscope (Page 4-20).
9. Enhance and label Figure 4.7 Coleus Stem Tip (m.l.s. an t.s.).
10. Compare Table 4.5 Selected Comparisons of Stems and roots of
Monocots and Dicots.
11. Prepare for a laboratory quiz to be given next week in lab.