AY 2023-2024

1 Compiled and Prepared by: SJRG

A. Course Title: GENERAL BOTANY (Composite lec and lab)
B. Course Code: BIO 100
C. Pre-requisite/s:
D. Course Description
Overview of plant body (cellular organization, tissues, systems), functioning & control
(integration & information flow, immunity & body regulations, respiration & photosynthesis),
habitat (niche, adaptation, impacts), evolution and reproduction (genetic, molecular,
biotechnology), embryonic development, and growth and development (metabolism).
E. Course Objectives
At the end of the course, the students should be able to:
a) Trace the history of the plant biology/botany;
b) Identify and describe the early branches, subdivisions and related disciplines of botany
and the personalities associated with them;
c) Identify, describe and employ the steps of the scientific method and its limitations;
d) Identify and describe the different plant body parts, its chemical compositions and niche;
e) Discuss briefly how plant reproduction and embryo development occurs, the movement &
regulation of water, ions, molecules and other cell products and the processes of
photosynthesis and respiration;
f) Identify the major group representatives in the plant kingdom and describe their evolution;
and
g) Photograph, draw, sketch, diagram, identify, label and describe the plant’s vegetative and
reproductive structures and relate them to item e.
F. Course Scope and Outline
a) Topics
A. INTRODUCTION (Review) Week 1
1. Science and Plant Biology
2. Scientific Method
3. Early and Modern Botanical Studies
4. Characteristics and Theories on the Origin of Life
B. Overview of Plant Morphology Week 2
1. Plant cell
2. Plant Tissues
3. The Root Structures & Functions Week 3
a. External and Internal Structure of the Root,
b. Specialized Roots and Root Systems
c. Environment of the Root
4. The Stem Structures & Functions Week 4
a. Origin and Development of Stems
b. External & Internal Organization of Stem Structure
c. Types and Specialized Stems
d. Mechanisms of Material Transport Week 5
e. Practical Application
MAJOR EXAM Week 6
5. The Leaf Structures & Functions Week 7
6. Flower, Fruit and Seed Structures & Functions Week 8 - 10
7. Plant Nutrition and Metabolism Week 11
8. Plant Growth & Development Week 12
9. Survey of the Plant Kingdom Week 13
10. Evolution of Plants Week 14
MAJOR EXAM Week 15

2 Compiled and Prepared by: SJRG

 b) Mode of delivery and Suggested Strategies & Tools
i. Online-Modular, written and reading assignments, E-materials, etc.
ii. Online Classroom/Platform (Google, Edmodo, Facebook, Messenger)
iii. Audio & Video Presentations, PPTs, PDFs/ebooks
c) Grading System
Lecture: 60% Laboratory: 40% Total: 100%
Major Exams 20% Lab reports 50% Passing rate:
Quizzes 50% Lab exam 40% 60%
Other requirements 20% Class participation / 10%
Class participation / 10% Interaction (chats/att/
Interaction (chats/att/ online meetings)
online meetings)
100% 100%
G. References / Credits
1. Bidlack, J.E. and S.H. Jansky. 2014. Stern’s Introductory Plant Biology. 13th ed. New York:
McGraw-Hill Education.
2. Biology Department,CNSM, MSU Marawi. Basic Biology Course Notes.
3. Campbell, N.A. and L.G. Mitchell and J.B. Reece. 2000. Biology Concepts & Connections. 3rd ed.
San Francisco: Benjamin Cummings - Addison Wesley Longman, Inc. 804-809pp.
4. Gealone-Corpus, A.M. 2015. Healthy Juices. Manila, Philippines: Philippine Publishing House.
5. Krogh, D. 2005. Biology: A Guide to the Natural World. 3rd ed. New York: Pearson Benjamin
Cummings. 777pp.
6. Mauseth, J.D. 2009. An Introduction to Plant Biology. 4th ed. Massachusetts: Jones and Bartlett
Publishers. 624pp.
7. Straten, M.V. 2018. The Natural Health Bible Quick Prescription from Nature’s Own Pharmacy.
London: Bounty Books for Hamlyn - Octopus Publishing Group Ltd.
Related Readings:
1. Adams, P. and J.J. Baker. 1970. The Study of Botany. Massachusetts: Addison-Wesley Publishing
Company. 556pp.
2. Audesirk, G. and T. Audesirk and B.E. Byers. 2009. Life on Earth. New York: Pearson Benjamin
Cummings. 122pp.
3. Archer, J., Austin, A and Check, S. 2005. Age of Botanical Discovery. Bellamine University.
4. Blouin, G. 2001. An Eclectic Guide to Trees East of the Rockies. Ontario: Boston Mills Press.
5. Bold, H.C. 1977. The Plant Kingdom. New York: Prentice-Hall. 283 pp.
6. Freeman, S. 2003. Biological Science. 3rd ed. Pearson Education, Inc. 1262pp.
7. Fuller, H.J. and D.D. Ritchie. 1967. General Botany: College Outline Series. New York: Barnes
and Nobles, Inc. 232pp.
8. Hufford, T.L. 1978. Botany: Basic Concepts in Plant Biology. New York: John Wiley and Sons,
Inc. 693pp.
9. Muller, W.H. and I. Greece. 1979. Botany A Functional Approach. 4th ed. New York: McMillan
Publishing Company, Inc. 687pp.
10. Ocampo, M.A. 2013. General Botany Manual. Makati, Philippines: Katha Publishing Company,
Inc.
11. Salisbury, F. and G. Ross. 1992. Plant Physiology. 3rd ed. New York: Wadsworth Publishing
Company
12. Taiz, L. and E. Zeiger. 1991. Plant Physiology. California: the Benjamin Cummings Publishing
Company
13. Weier, T.E. and C.R. Stocking and M.G. Barnes. 1974. Botany: AN Introduction to Plant Biology.
New York: John Wiley and Sons, Inc. 683pp.

3 Compiled and Prepared by: SJRG

 LESSON 4
STEMS

This lesson discusses, in general, the origin and development of stems. Structures
such as the apical meristem and tissues derived from it are included. It is followed
by notes on the distinctions between herbaceous and woody dicot stem and
monocot stems. It also covers annual rings, rays, heartwood, sapwood, resin
canals, bark, lacticifers and vascular bundles.
Next, there is a survey of specialized stems and a discussion of the economic
importance of woods and stems. This also introduces molecular movement and activity in plants
starting from entry of water into plants to evaporation of water and transpiration.

Learning Goals and Objectives:

At the end of the lesson, the student will be able to:
1. Identify the different parts and tissues comprising a plant stem. Give their
functions.
2. Describe the differences in the development of dicot and monocot stems
3. Describe the composition of wood and its annual rings, sapwood,
heartwood and bark. Explain how a log is sawed for commercial use.
4. Provide descriptions of specialized stems.
5. List at least 10 human uses of wood and stems in general.
6. Explain the transport of water and nutrients in the xylem and phloem.
7. Define diffusion, osmosis, turgor, inhibition and active transport.
8. Explain the process of leaf abscission and the factors involved.
9. Discuss the opening and closing of the stomata.
10. Discuss the process of transpiration and the factors involved.
11. Compare and contrast transpiration and guttation.

Topic Outline
A. Origin and Development of Stems
B. The Stem Structure and Functions
C. Specialized Stems
D. Mechanisms of Material Transport
E. Practical Application of the Knowledge on Stem Structure and Function

Activating Prior Knowledge

Reflect on the learning outcomes above. Complete the table below:

Learning What do you know? Questions/clarifications related

Outcomes to the learning outcomes
1
2
3
4
5

4 Compiled and Prepared by: SJRG

 6
7
8
9
10
11

Review Concept:
There is an apical meristem (tissue that actively divide) at the tip of each stem and
it is this meristem that contributes to an increase in length of the stem. It is
dormant (same w/ embryonic stem of seed) before the growing season begins (or
a seed germinates) and is protected by bud scales of the bud in which it is located
and to a certain extent by leaf primordia (sing. primordium), the tiny embryonic leaves that will
develop into mature leaves after the bid scales drop off and growth begins.

Apical Meristem

5 Compiled and Prepared by: SJRG

 Overview of Plant Structure: Stem

Stems
• Above-ground organs (usually)
• May be vegetative (leaf bearing) or reproductive (flower bearing).

Functions of Stems:
• Supports branches, leaves, flowers, fruits and seeds
• Stems transport water and solutes between roots and leaves.
Translocation-moves water, sugars and minerals from roots up to the leaves and move food
from the leaves down to the roots (xylem and phloem)
• Stems in some plants are photosynthetic.
• Stems may store materials necessary for life (e.g., water, starch, sugar).
• In some plants, stems have become adapted for specialized functions.

2 types of stems
Herbaceous stems
• In herbaceous plants and young woody plants, the stem is covered with epidermis.
• Epidermis secretes cuticle, has stomata, and may be photosynthetic.
• Soft, green, flexible
• Annuals, biennials, or perennials that die to the ground at the end of the growing season
Woody stems
• Soft, green, flexible
• Hard, produce secondary growth
• May go dormant at the end of a growing season

External Stem Structures

• Apical meristem - growing point at the tip of the stem
o The apical meristem is the same type of structure as that found on the tip of the root,
and it is responsible for growth in the length of the plant.

6 Compiled and Prepared by: SJRG

• Terminal bud - bud at the end of the stem
• Node- area of stem where leaf is born
• Internodes- stem area between nodes

• Buds: Stem elongation. Embryonic tissue of leaves and stem (not flower bud)
o Terminal bud- Located at tip of stems or branches.
o Axillary bud- Gives rise to branches
o Lateral bud = side bud - at node, just above where the leaf is attached
• Bud scales = small protective structures, on outside of terminal and lateral buds
o Bud scale scar = ring of scars from when the buds sprout each spring & bud scales fall
off
o The distance between bud scale scars represents one year’s growth of the stem.
• Leaf scar = Small scar just below the lateral bud from when the leaf falls off the stem
• Lenticels “breathing pores”- small spots on stem, allow a stem to exchange gases
• Apical Dominance: Prevention of branch formation by terminal bud

Internal Stem Structures

Stems have all three types of plant tissue
• Grow by division at meristems
– Develop into leaves, other shoots, and even flowers

7 Compiled and Prepared by: SJRG

1) Epidermis (Dermal tissue type)
• Provides protection and has cuticle (wax) prevents water loss
• Trichomes (hairs) for protection, to release scents, oils, etc.

2) Stem Ground tissue: Cortex & pith

• Some major types of plant cells:
• Parenchyma
Characteristics
• least specialized cell type; generally alive at functional maturity
• only thin primary cell wall is present and possess large central vacuole
Functions
• make up most of the ground tissues of the plant
• for storage & photosynthesis
• can help repair and replace damaged organs by proliferation and specialization
into other cells
• Collenchyma
Characteristics
• possess thicker primary cell walls the that of parenchyma
• no secondary cell wall present and generally alive at functional maturity
Functions
• provide support without restraining growth
• Sclerenchyma
Characteristics
• have secondary cell walls strengthened by lignin
• often are dead at functional maturity; two forms: fibers and sclereids
• Fibers are long, slender and tapered, and usually occur in groups.
• Those from hemp fibers are used for making rope and those from flax for
weaving into linen.
• Sclereids, shorter than fibers and irregular in shape
• impart the hardness to nutshells and seed coats and the gritty texture to
pear fruits.
Functions
• rigid cells providing support and strength to tissues
• Tissues that are neither dermal nor vascular are ground tissue
• Ground tissue includes cells specialized for storage, photosynthesis, and support
• Ground tissue internal to the vascular tissue is pith; ground tissue external to the vascular
tissue is cortex
• Cortex layer contains parenchyma cells and vascular bundles.
• Pith makes up the center of the stem and is absent in hollow stems.

3) Stem Vascular tissue

• Runs continuous throughout the plant and transports materials between roots and shoots.
• Xylem transports water and dissolved minerals upward from roots into the shoots. (water the
xylem)
• Phloem transports food from the leaves to the roots and to non-photosynthetic parts of the
shoot system. (feed the phloem)
• Vascular bundles – composed of both xylem and phloem
• Occurs in woody stems
• Vascular cambium located in the middle of the vascular bundle, between xylem and
phloem (in the cortex)

8 Compiled and Prepared by: SJRG

 • Cambium-thin, green, actively growing tissue located between bark and wood and
produces all new stem cells
• While primary xylem and phloem are made by the apical meristem, secondary xylem and
phloem come from the vascular cambium, another meristem tissue.
• Vascular tissue is located on the outer layers of the tree.

Wood and Bark

• Xylem makes up the wood of trees and shrubs.
• Live phloem cells form the green bark.
• Dead cork cells make up the bark.
• Bark-old inactive phloem • Sapwood-new active xylem
• Heartwood-old inactive xylem

Wood and Bark

Annual Rings
• Trees in temperate zones grow at different rates in different seasons, causing annual rings to
form.
• In some parts of the tropics, if seasons vary little, tree rings are indistinct.
• Annual rings: xylem formed by the vascular cambium during one growing season
• One ring = one year
Vascular Rays
 Rays allow for the lateral movement of water, dissolved minerals, sugars, and waste
products within the stem.

Monocot Stem
- Have epidermis that provides protection
- Xylem & phloem are grouped in vascular bundles throughout stem extending entire length
- Xylem inside, phloem outside, lack cambium
Dicot Stem
- Have epidermis with cortex for protection comprised of vascular bundles that form a ring
- Xylem inside, phloem outside, cambium between
- Center of the stem pith (storage)

9 Compiled and Prepared by: SJRG

 Cross sections of monocot and herbaceous dicot stems
Monocot stem: vascular bundles are dispersed; Dicot stem: vascular bundles in ring

We generally expect stems to be upright and above ground, but many stems do not fit into this mold.
Some stems are modified to store food or help the plant reproduce. Some stems grow beneath the
soil instead of above it. Modified shoots with diverse functions have evolved in many plants. These
shoots, which include stolons, rhizomes, tubers, and bulbs, are often mistaken for roots.
– Rhizome: Thick stems that grow below the ground, often near the surface of the soil.
• Example: (relatively thick, fleshy, food-storage organ) Irises and
(quite slender) many perennial grasses or some ferns

– Runners: Horizontal stem which grow aboveground and generally along the surface; have
long internodes with adventitious buds that appear at alternately at nodes and can be
separated and grown independently.
• Example: Strawberry runners

– Stolon: Stem produced beneath the surface of the ground and tend to grow in different
directions but usually not horizontal.
• Example: In Irish potato plants, tubers are produced at the tips of stolon.

10 Compiled and Prepared by: SJRG

 • Some botanists consider stolon and runners to be variations of each other and prefer
not to make a distinction between them.

– Tuber: swollen internodes at the tip of stolon caused by accumulation of food.

• Example: Potatoes.

– Bulb: very short, flattened stem with several fleshy leaves attached and tend to be found
beneath the soil.
• Tunicate bulbs have a papery outer covering. An onion is an example.

Scales: modified leaves that store carbohydrates

Apical bud: sits on top of the basal plate. Will eventually

form a shoot bearing leaves and flowers

Basal plate: modified stem

• Scaly bulbs lack a papery outer covering. Lily bulbs are an example.

– Corm: spherical structure, much like a bulb but entire structure, is stem as opposed to
stem & leaves.
• Example: Gladiolus.

Corm Development

– Cladophylls: flattened and with a node bearing very small, scale-like leaves with axillary
bud in the center.
• Example: asparagus, certain orchids, prickly pear cacti.

Other Specialized Stems:

– Cacti are examples of succulent plants with stems that are stout and fleshy because they
store water in their stems.
• The spines are modified leaves.

– Spurs: Short, slow-growing stems that bear leaves, flowers, or fruit.

• Example: Ginko biloba; Not found on all species.

11 Compiled and Prepared by: SJRG

 Modified Stems

What is plant anatomy?

• ANATOMY: study of the structure of organisms… looking at cells, tissues
• (Morphology: Study of form)
What is plant physiology?
• PHYSIOLOGY: study of the function of cells, tissues, organs of living things;
• and the physics/chemistry of these functions…
“Structure correlates to function”

Review Concepts
Brownian movement - the random motion of small particles suspended in a gas or liquid
Material Transport:
A. Passive transport – transport of a substance across a cell membrane by diffusion;
expenditure of energy is not required
a. Diffusion - movement of molecules from high to low concentration
b. Osmosis - diffusion of molecules through a semipermeable membrane from a place of
higher concentration to a place of lower concentration until the concentration on
both sides is equal
Solute – the dissolved matter in a solution; the component of a solution that changes its state
Solvent - a liquid substance capable of dissolving other substances
Osmotic potential (ψS)– measure of the potential of water to move from one cell to another as
influenced by solute concentration
Osmotic pressure – the pressure exerted by a solution necessary to prevent osmosis into that
solution when it is separated from the pure solvent by a semipermeable membrane

12 Compiled and Prepared by: SJRG

Turgor pressure – pressure from turgidity (turgid - abnormally distended especially by fluids or
gas / firmness) of a cell due to entrance of water into the cell by osmosis until the osmotic
potential is balanced by the resistance to expansion of cell wall
Pressure potential (ψP)– pressure that develops against the walls as a result of water entering
the vacuole of the cell
Water potential (ψW)– is essentially the osmotic potential and the pressure potential combined.
Plasmolysis - the shrinking of protoplasm away from the cell wall of a plant or bacterium due to
water loss
Inhibition – is the attraction and adhesion of water molecules to the internal surfaces of
materials and results in swelling and is the initial step in the germination of seeds
B. Active transport – transport of a substance (as a protein or drug) across a cell membrane
against the concentration gradient; requires an expenditure of energy
C. Bulk transport
a. Endocytosis - process by which the plasma membrane of a cell folds inwards to
ingest material.
b. Exocytosis - the secretion of substances through cellular membranes, either to
excrete waste products or as a regulatory function
i. Pinocytosis - process by which certain cells can engulf and incorporate
droplets of fluid
ii. Phagocytosis – e.g., in animals, it is a process in which phagocytes engulf and
digest microorganisms and cellular debris; an important defense against
infection

Simple Diffusion. 1st: a barrier e.g., semi-permeable

membrane (membrane through which substances diffuse
at different rates) separates 2 kinds of individual
molecules; 2nd: when barrier is removed, random
movement of individual molecules results in both kinds
moving from a region of higher concentration to a region
of lower concentration; 3rd: eventually, equilibrium (even
distribution) is reached. The rate of diffusion gradually
slows down as equilibrium is approached.

• Turgid-plant is swollen or filled with moisture

• Wilted-plant is limp because it does not have enough moisture

Plants mostly obtain water & minerals from soil. Water moves up the xylem by bulk flow.
Movement of water depends on transpiration pull, cohesion & adhesion of water molecules,
capillary forces, and strong cell walls.

13 Compiled and Prepared by: SJRG

 Water in plant cells

Transpiration-cohesion Theory: for water transport in the xylem

Or Cohesion-Tension Theory states that water rises through plants because of the adhesion
of water molecules to the walls of the capillary-conducting elements of the xylem, cohesion of water
molecules, and tension on the water columns created by the pull developed by transpiration.
Evaporation of water in the leaves (through stomates) generates the ‘sucking force’ that pulls
adjacent water molecules up the leaf surface
• Like a long chain, water molecules pull each other up the column.
• The column goes from roots  leaves.
• What’s amazing is that water moves up by using the sun’s evaporative energy.
• Plants control transpiration by opening/closing stomata
Transpiration is the emission of water vapor from the leaves of plants
• Large amounts of water vapor are lost by transpiration.
– 2 liters of water/day for a single corn plant
– 5 liters for a sunflower
– 200 liters for a large maple tree
– 450 liters for a date palm tree
• Transpiration is a major component of the global water cycle.

Translocation is the transport of dissolved material within a plant: for food transport in phloem
Translocation of food substances take place in a water solution, and according to the
pressure-flow hypothesis, such substances flow along concentration gradients between their
sources and sinks.
Sugar translocation
1. Sugars made in leaf mesophyll cells (source) diffuse to phloem cells in the vascular
bundles.
2. Companion cells load dissolved sugars into the phloem STM using energy (ATP).
3. Water moves into cells with high sugar concentration.
4. Osmotic water flow generates a high hydraulic pressure that moves dissolved sugars
through the phloem to the rest of the plant (sink).

Ascent of xylem sap:

Transpirational pull - flow from greater to lower water concentration
Relies on cohesion & adhesion of water cavitation breaks chain of water molecules

14 Compiled and Prepared by: SJRG

Transpiration is regulated by humidity and the stomata which open and close through changes in
turgor pressure of the guard cells. These changes, which involve potassium ions, result from
osmosis and active transport between the guard cells in the adjacent epidermal cells.

Transport of molecules in Plants

Role of potassium in stomatal opening and closing. The transport of K+

(potassium ions, symbolized here as red dots) across the plasma membrane
& vacuolar membrane causes the turgor changes of guard cells.

 Aquatic, desert, tropical and some cold-zone plants

have stomatal modifications for photosynthesis that
adapt them to their particular environments.

Guttation – the loss or exudation of water from the leaves

of some vascular plants at night in liquid
form through hydathodes at the tips of leaf veins as a result
of root pressure

15 Compiled and Prepared by: SJRG

 Girdling: cutting around a tree
Damages the phloem and xylem, eventually killing the tree!

Density is among the most important physical properties of wood. Some of the heaviest woods,
such as those obtained from West Indian trees, are extremely hard and have been used instead of
metals in the manufacture of main bearings for drive shafts of submarines because they are
self-lubricating and less noisy.

Durability is the wood’s ability to withstand decay caused by organisms and insects. Moisture is
needed for enzymatic breakdown of cellulose and other wood substances by decay organisms, but
the seasoning process usually reduces the moisture to a level below that necessary for fungi and
other decay organisms to survive. Other natural constituents of wood that repel decay organisms
include tannins and oils.

Types of Sawing
Quartersawed – or radially cut boards show the annual rings in side view which appear
longitudinal streaks and are the most conspicuous feature of the wood.
Tangentially cut – or boards cut perpendicular to the rays are more common. The annual rings
appear irregular bands of light and dark alternating streaks or patches, with the ends of rays
visible as narrower and less conspicuous vertical streaks.
Examples: plain-sawed or slab (boards with rounded sides at the outside of the log) cut
boards used in lumber or usually made into chips for pulping
Knots are the bases of lost branches that have become covered, over a period of time, by
new annual rings of wood produced by the cambium of the trunk.

Wood Products
Wood produced is used as lumber, primarily for construction, and the sawdust and other wastes
formed in processing boards are converted to particle boards and pulp.
Veneer – very thin sheet of desirable wood that is carefully cut to produce the best possible
view of the grain and then usually glued to cheaper lumber in making furniture.
Lacticifers – latex-secreting cells or ducts found in various flowering plants.

1) What is the function of bud scales?

2) How can you tell the age of a twig?
3) Distinguish among procambium, vascular cambium, and
cork cambium.
4) How can you tell, when you look at a cross section of a
young stem, whether it is a dicot or a monocot?
5) An Irish or white potato is a stem, but a sweet potato is a root. How can you
tell?
6) Distinguish among corms, bulbs and others.
7) Why do living plants need a great deal of water for their activities?
8) Explain how a tall tree gets water to its tips without the aid of mechanical
pump.

16 Compiled and Prepared by: SJRG

 9) What is the difference between transpiration and guttation?
10) Explain pressure-flow hypothesis.
11) If you are examining the top of a wooden desk, how could you tell if that a
wood had been radially or tangentially cut (quartersawed or plain-sawed)?
12) What differences are there between heartwood and sapwood?
13) What is meant by the specific gravity of wood?
14) What are other modifications/specialized stems characterized by other
plants?

1) If the cambium of a tropical tree were active all year long,

how would its wood differ from that of a typical temperate
climate tree?
2) A nail driven into the side of a tree will remain at exactly
the same distance from the ground for the life of the tree.
Why?
3) Do climbing plants have any advantages over erect plants? Any
disadvantages?
4) If two leaves are removed from a plant and one is coated with petroleum jelly,
while the other is not, the uncoated leaf will shrivel considerably sooner than
the coated one. Would it be helpful to coat the stems of young trees with
petroleum jelly? Explain.
5) Why does osmosis not cause submerged water plants to swell up and burst?
6) Suggest some reasons for heartwood being preferred to sapwood for making
furniture.

Advanced English Dictionary based on WordNet® by Princeton University.

Downloaded from http://wordnet.princton.edu. Database Version: WordNet 3.1
Bidlack, J.E. and Jansky, S.H. 2014. Stern’s Introductory Plant Biology. 13th edition.
New York. McGraw-Hill Education. Chapter 6.
Campbell, N.A. and L.G. Mitchell and J.B. Reece. 2000. Biology Concepts &
Connections. 3rd ed. San Francisco: Benjamin Cummings - Addison Wesley
Longman, Inc.
Botany essential notes. http://web.fscj.edu/David.Byres/botanynotes/
Review Lecture Notes. http://www.bio.miami.edu/dana/226/226F09.html
Short Course in Herbalism.
http://www1.biologie.uni-hamburg.de/b-online/ibc99/dr-duke/module1.htm

http://www.mhhe.com/stern13e

17 Compiled and Prepared by: SJRG

https://www.pbs.org/wgbh/nova/
https://learn.genetics.utah.edu/
https://fastplants.org/
https://phet.colorado.edu/
https://sciencetrek.org/sciencetrek/topics/botany/games.cfm

18 Compiled and Prepared by: SJRG