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Botany for Arborists
Jim Downer
[email protected]
805 645 1458
805-645-1458
http://ceventura.ucdavis.edu
L d
Landscape
N
Notes
t
Many of the slides in this presentation are from Raven, Evert and Eichhorn, 2005. W.H.
Freeman and Company, New York ISBN 0-7167-1007-2,
Botany? Arborists? Why???
• Professionalism
• Knowledge of how plants (especially trees)
function
• This lecture introduces the article series
b i published
being
bli h d iin each
h iissue off W
Western
t
Arborist.
Botany is not
not…
•
•
•
•
•
•
Horticulture
Plant pathology
S il science
Soil
i
Entomology
Geology or
Biology
Botany is
is…
•
•
•
•
•
Nomenclature
Taxonomy
A t
Anatomy
and
d morphology
h l
Physiology
Genetics and reproduction
How we present information
• “Its
Its big, its green, its bushy! Look at all
these sprouts! It’s a healthy tree!”
• Your tree is large it has a dense canopy,
leaf retention is above average
average. Your tree
appears healthy!
• It
I comes down
d
to NOMENCLATURE
Nomenclature
• International Code of Botanical nomenclature
–
–
–
–
–
A stable method of naming all plants
Avoids useless creation of names
Provides grammatical correctness of names
Establishes starting dates for all names
Always in Latin
• Genus: generic name is a noun (singular)
• Species: specific epithet is an adjective
Rules of Nomenclature
•
•
•
•
•
Linnaeus
Fragmenta botanica (1736)
(
)
Critica botanic (1737)
Philosophia botanica (1751)
Priority: the concept that the first validly
proposed name has priority over all others
• Theorie elementaire de la botanique (1813)
• First
Fi International
I
i
l Botanical
B
i l Congress
C
(1867)
(186 )
• American Code (1892-1910)
Genera are named for:
• People: Lewissia, Clarkia (for Lewis and Clark)
• Greek+Latin words: Helianthus from helio, sun;
anthos,, flower.
• Some without meaning: Alnus- Alder
Iberia Spain; Idahoa,
Idahoa Idaho
• Based on location: Iberia,
• Anagrams: Lobivia, Bolivia; Legenere, E.L.
G ee e
Greene
Type specimen of the
angiosperm
P d d
Podandrogyne
fformosa
which is found in Costa
Rica and western
Panama.
This specimen was
collected by Theodore S.
Cochrane and described
b hi
by
him iin a paper
published in the journal
Britonnia 30:405-410 in
1978.
Terminations
G d
Genders
must agree
• Eriogonum polypodum
polypodum, Eucalyptus
globulus, Sinningia leucotricha
• Gender of the specific eptithet always
determined by the gender of the generic name
• Trees,
Trees no matter the generic termination are
always have a feminine ending
• Terminations can be for people
– Clarkia dudleyana for William Dudley (1849-1911)
Scientific Names
always
l
iinclude
l d authorships
h hi
• Sanicula marilandica L.
L
• Things can change
– Erigeron
Ei
canadensis
d
i L.
L tto Conyza
C
canadensis
d
i
(L.) Cronquist
Division Magnoliophyta Takht., Cronquist & W. Zimm. ex Reveal, 1996
Class Magnoliopsida Brongn., 1843
Subclass MagnoliidaeNovák ex Takht., 1967
Superorder Magnolianae Takht., 1967
Order Magnoliales Bromhead, 1838
S b d Magnoliineae
Suborder
M
lii
E l 1898
Engl.,
Family Magnoliaceae Juss., 1789
Subfamily Magnolioideae (Juss.) Arn., 1832
Genus Magnolia L.,
L 1753
Species virginiana L., 1753
Type: Clifford Herbarium 222 Magnolia No. 1 (BM)
How do you correctly write a plant
name?
?
•
•
•
•
Genus and species
Italics, or underline
G
Genus
capitalized
it li d species
i nott
Authorities
Capsicum annuum L.
L
How are trees put together?
• Cells
• Tissues (Epidermal, ground, vascular)
• Organs
O
– Roots
– Stems
– Leaves
– Flowers or cones
Robert Hooke, ca 1670, first used the simple microscope
To discover the cellular nature of cork.
Hooke’s Cork
Cell Functions
•
A. Serves as the structural building block to form tissues and organs
•
B. Each cell is functionally independent- it can live on its own under
the right
conditions
1 it can d
1.
define
fi itits b
boundaries
d i and
d protect
t t ititself
lf ffrom external
t
l
changes causing internal changes
2. it can use sugars to derive energy for different processes
which keep it alive
3 it contains
3.
t i allll th
the iinformation
f
ti required
i d ffor replicating
li ti ititself
lf
and interacting with other cells in order to produce a multicellular
organism
4. It is even possible to reproduce the entire plant from
almost
l
t any single
i l cellll off th
the plant
l t
Plant cells
cells- the basic building blocks.
•
•
•
each cell is approximately 1/101/10 1/100th
of a millimeter long
cells can specialize in form and function
to provide certain specialized functions to
p
the whole plant
Each cell can live on its own under
y working
g
certain conditions- however, by
together they provide a way to survive in
more varied conditions
Types of Cells
• A. Prokaryotic cells- eg. bacteria
1 very simple-there
1.
i l th
are no organelles
ll and
d mostt
everything functions in the cytoplasm
• B. Eukaryotic cells
1 allll contain
1.
t i th
the organelles
ll th
thatt
subcompartmentalize the cell
2. includes unicellular algae and protists (e.g.
amoeba) that live alone or in colonies
3. includes multicellular organisms - animals,
plants, fungi - where cells work together
a. p
plant cells are unlike animal cells in that
plant cells have chloroplasts and cell walls.
Animal cells have neither of these. Plant cells
also have relatively large vacuoles.
Escherichia coli
N l l
Nucleolus
Nucleus
Chromatin
DNA + Histones
Mitochondria
Chloroplasts
Vacuole
Tree Cells
• Trees are made of
cells
• Cells can not be
“healed”
produce new
• Trees p
cells in new locations
to cover over wounds
(A Shi
(A.
Shigo))
Tree growth
•
Is fundamentally different from animal growth.
•
Animal g
growth is determinate; an animal embryo
y develops
p into a
young animal, then an adult. In other words, the overall shape of the
adult animal is genetically determined from its earliest
developmental stages. Once an animal has become an adult, it may
become heavier or fatter, but it will not become larger.
•
Tree growth is often indeterminate; even an adult plant retains tiny
regions of embryonic tissue called meristems that are capable of
developing into new parts of the plant
plant. Although the plant does grow
according to a set of rules (similar to a fractal), the tree is growing
new shoots and roots for as long as it is alive. Thus the ultimate
exact shape of the tree is not determined in advance, and the
growth is said to be indeterminate
indeterminate.
•
Ultimately growth is made by dividing cells!
Mitosis
• Four major phases: prophase, metaphase,
anaphase
p
and telophase.
p
• Prophase: chromatin condenses into
chromosomes. Sister chromatids are joined at
the
h centromere. P
Prophase
h
ends
d with
i h di
dissolution
l i
of the nuclear membrane and nucleolus.
Prophase is the longest phase of mitosis
mitosis.
• Metaphase: development of the mitotic spindle
and the kinetochore. Polar microtubules and
kinetochore microtubules are clearly formed.
Chromosomes line up on the equatorial plane or
metaphase plate
plate.
Tree Growth
• Meristems are regions
g
of embryonic
y
tissue
capable of growing into new plant parts.
Meristems are found in both roots and shoots.
– Primary meristems make the shoot or root grow
longer. This kind of growth is called primary growth.
• A shoot apical meristem is found within each bud.
• A root apical
p
meristem is found at the tip
p of each root, and is
protected by the root cap.
– Secondary meristems make the stem or root grow
larger in diameter. This kind of growth is called
secondary
d
growth.
th N
Nott allll ki
kinds
d off plants
l t are capable
bl
of secondary growth. Secondary growth gives rise to
wood, and plants that are not capable of secondary
growth do not develop wood
wood.
Plant tissues
•
Unlike animals, the major organs of plants (roots, stems, and leaves) are
all composed of the same three tissues (epidermis, vascular tissues, and
ground tissues)
tissues).
Each tissue carries out the same fundamental activities throughout the
plant.
Three types of tissues
•
•
–
Epidermis - the exchange of matter between the plant and the environment
environment.
•
•
–
Vascular tissues - the transport
p of water and dissolved substances inside the
plant
•
•
–
the xylem carries water and dissolved ions from the roots to stems and leaves
the phloem carries dissolved sugars from the leaves to all other parts of the plant
Ground tissues - metabolism, storage, and support activities
•
•
•
•
•
the epidermis on aboveground organs (leaves and stems) is involved with gas
exchange
the epidermis on belowground organs (roots) is involved with water and ion uptake
the ground tissue of the leaf (called mesophyll) uses the energy in sunlight to
synthesize sugars in a process known as photosynthesis
the ground tissue of the stem (called pith and cortex) develops support cells to hold
the young plant upright
the ground tissue of the root (also called cortex) often stores energy- rich
carbohydrates
Growth of plant tissues give rise to complicated structure
Tree Structure
Tissues give rise to organs that comprise the structure of the tree
•
Shoots
–
Shoots are made of leaves attached to a stem.
Leaves (singular; plural is leaves)
–
Leaves are often the primary site of photosynthesis.
•
Stems
– Holds leaves, transports and stores water and
nutrients and is sometimes photosynthetic.
nutrients,
photosynthetic
•
Roots
•
--
---
Anchorage, supports the stem
Absorption of water and minerals
Storage of sugars
Buds
Buds can develop into new shoots. Buds are named
according
di to
t where
h
they
th occur on th
the shoot.
h t E
Each
h shoot
h t
has an apical bud at the tip of the shoot, as well as an
axillary bud associated with each leaf.
– Apical Bud
• The apical bud is found at tip (or "apex") of the shoot.
• This is the point from which the shoot will grow.
– Axillary
a y Buds
uds
• The angle between the leaf and stem is called the axil.
• There is normally a bud in the axil of each leaf
• Axillary buds are of elongating into a new shoot (a branch).
Therefore there will be a leaf (or a leaf scar) below each branch on
a stem. In trees the leaf scars disappear over time, but on young
branches of trees the leaf scars are easy to find.
Other kinds of buds
• Adventitious buds
• Latent Buds
– Lead to epicormic
shoots
Bud Anatomy
• Apical Meristem
• Leaf primordia
• procambium
Leaves
organs of photosynthesis
•
Relate anatomy of leaf to its primary function of photosynthesis
–
•
carbon dioxide + water ------->
> sugar + oxygen
Major tissues of the leaf
–
Epidermis
•
•
–
Mesophyll
•
•
–
Site of photosynthesis
Air spaces between cells for gas exchange to each cell
Veins
•
•
•
•
•
Transparent- light goes right through
Transparent
(a) Main function - protects against drying out (cuticle)
(b) Stomata with guard cells
Function- gas exchange, especially common on lower epidermis
Xylem- water conduction
Phloem- food conduction
Bundle sheath- one or more layers of fiber cells surrounding a vein; strengthens vein
to support leaf
Branching extensive in veins- no mesophyll cell is far from a vein
Transpiration- loss of water vapor
Abscission leaf fall
Abscission-
Leaf Anatomy
•
•
•
•
•
•
Blade or lamina
Petiole
Stipule
Leaf Arrangement
Leaf phyllotaxy
Leaf types
Compound Leaves
• Pinnate
• Palmate
• Once,
O
twice
t i thrice
th i
Maple
Ginko
Peach
Leaf Arrangement or Phyllotaxy
Inside the leaf
Stomata
• Stomata a site of
transpiration (water
vapor loss)
• Generally more on
the bottom of the leaf
than the top
Mineral Nutrition
• Leaves are the
window into a
plant’s
plant
s mineral
nutrient status
• Macro:N,P,K,S,Ca,
Macro:N P K S Ca
Mg
• Micro:Fe,Zn,B,Mn,
Mi
F Z BM
Ni,Cl, Cu, Mo,
Stems and Branches
• Buds lead to the
p
of branches
development
and main stems
• Health and vigor can be
determined by the
amount of growth
observed between buds
• Twigs lead to branches
and branches lead to the
need for pruning
Stems
• Functions of Stems
– Support leaves and
fruits
– Conduction of water
and sugars throughout
plant
– Storage of sugars or
starch
Tissues of stem
•
Epidermis
–
–
•
Protection
P
t ti
Cuticle to conserve moisture
Cortex
–
–
–
–
•
Store food
Photosynthesis (when stem is green)
Some support cells
pith to store food
Xylem
–
–
•
Conduction of water and minerals
Second function - has strong
g supporting
pp
g cells ((fibers))
Phloem
–
–
Conduction of sugars, hormones, phytochemicals
Second function - storage
Stems with secondary growth
• Devleopment of the
vascular cambium is
unique to woody
plants
• The pith gets crushed
• It all starts with the
Shoot Apical
M i
Meristem
Buds give rise to all the cells that will
eventually
t ll d
develop
l wood
d
wood
• If for no other reason
a tree is a tree
because of its wood.
Wood
Phloem<>
oe
---XYLEM----------------------------
Oak
Wood
Sections
Pine
rs
xs
ts
Carob
Quercus
Hardwoods Oak
Hardwoods,
Oak, willow
willow, basswood
• Major cell type in the
xylem is the vessel
element
• They are huge, round,
thin walled, hundreds
of times larger than
trachieds.
Conifers Pines,
Conifers,
Pines cedar etc
• Major cell type in the
xylem is the trachied.
• These are narrow
thick walled and long
• Trachieds can
intergrade into fiber
t hi d and
trachieds
d fib
fibers.
Conifer wood
Tilia americana (basswood)
a ring
i porous wood
d
Basswood: ring porous
The strategy for palms
monocots!!
Reaction Wood
Bottom of tree
Compression wood (Shigo)
Wood Reacts
•
•
•
•
To internal defects
To pruning wounds
To insects
To forces that pull or
push on stems
• To gravity
Natural Target Pruning
35o
32o
~35o
Not So Good Cuts
25o
Bad cuts
fl
h cuts
flush
>35o
44o
Included bark
Dealing with codominance
A philosophy of pruning
• Pruning should
accomplish
predetermined goals
while striving to limit
the formation of
d
decay
columns
l
within
ithi
the tree’s major
branches and stems
stems.
Root
•
The root anchors the plant in the soil, absorbs water and mineral
nutrients from the soil
soil, and often serves for storage
storage.
Roots are underground, so people don't think very much about
them, but they are very important.
Branch Roots
•
•
–
–
•
Roots do not have leaves or axillary buds
Branch roots emerge from the inside of the root
Root Hairs
–
–
•
Absorption
Ab
ti
Found just behind growing tip of root
Root Cap
–
–
Protects the delicate tip of the root as it grows through the soil.
Found in front of the root apical meristem.
Roots
•
Functions
–
–
–
–
•
Anchorage
Absorption of water and dissolved minerals
Storage
g ((surplus
p
sugars
g
transported
p
from leaves))
Conduction
Epidermis
–
Single layer of cells for protection (from disease organisms)
and absorption (water and dissolved minerals)
–
Root hairs- tubular extensions of epidermal
p
cells
•
•
•
short lived
greatly increase surface area of root, in contact with soil
confined largely to the region of maturation of the root
Roots
•
•
Cortex
–
Store starch and other substances
–
Contain numerous intercellular spaces - air spaces essential for aeration of
the root cells (for cellular respiration)
Xylem
–
Conducts water and dissolved minerals
–
composed of
•
a) vessels: tube
tube-like
like structures composed of hollow elongate cells
(vessel members) placed end-to-end and connected by
perforations
•
a)) tracheids: elongated
g
conducting
g and supporting
pp
g cells with
tapering and pitted walls without perforations
–
–
Upward movement caused by transpiration from the leaves aided by
the properties of water: polarity of water molecules, cohesion of water
molecules to each other, adhesion to xylem cell walls
V
Very
rapidid 2 ffeet/
t/ minute
i t
Roots
•
Phloem
–
–
Conducts food (dissolved sugar)
Phloem composed of sieve elements (sieve
tube members, companion cells)
•
•
•
Sieve tube is a series of sieve tube members
arranged end-to-end and interconnected by
sieve plates
Movement of sugars up or down through
plasmodesmata of sieve elements
One inch/ minute
Roots and Root systems
Root Anatomy
• There are many kinds
of root systems
• Some root systems
y
have no hair roots
• Ecto and
Endomycorrhizae
change the root
appearance
Mycorrhizae
Root Development
Roots have some unique structures
• Pericycle
– Endodermis
• Cortex
Metasequoia
• Root showing
secondary growth
• Pith is gone and
crushed.
Secondary STEM,
note annual rings
phloem
differentiation.
differentiation
Plant Physiology
• Plants are p
photosynthetic
y
-- theyy g
gather their food energy
gy
directly from sunlight
• To perform photosynthesis, plants need to have a supply
of:
–
–
–
–
Sunlight
Carbon dioxide gas from the atmosphere
Water
Mineral nutrients
• During photosynthesis, plants release Oxygen, but they
need to use oxygen at night and in parts of the plant (like
the roots) that do not perform photosynthesis.
photosynthesis
• The structure of a plant is adapted to gathering the
things that the plant needs.
Physiology
y
gy
• Photosynthesis
– (6C02 +24H20 + light  C6H12O6 +6O2+18H20)
– 3CO2 +6H
6H2O + light
li ht C3H6O3 + 3O2 +3H
3H2O
• Respiration
– C6H12O6 + 6O2  6C02 + 6H20 +Chem E + Heat
• Transpiration
T
i ti
– Water loss from plant surfaces due to Ps
• Guttation
– Water loss from plant surfaces due to Rs
• Hormonal regulation of plant growth
– Auxins, cytokinins, gibberelin, ethylene, abscisic acid
– http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookPLANTH
ORM.html
Uptake
Solute movement
• Symplastic
• Apoplastic
movement
movement
Cohesion
C
h i
tension
theory of
water
movement
Driving force for water movement is
at the
h lleaf!
f!
Plant Reproduction
•
•
•
•
•
•
•
•
Asexual Reproduction
B
Because
plant
l
growth
h iis iindeterminate,
d
i
each
h meristem
i
can
potentially develop into a complete plant. This means that it is very
easy to clone plants, and many plants can grow from cuttings or
broken plant parts. This is asexual reproduction (also called
vegetative
t ti reproduction).
d ti )
Sexual Reproduction
Alternation of Generations - plant sexual reproduction is unusual,
and involves an alternation between two partially independent life
stages. We will discuss this later in the course.
Flowers are special reproductive structures found in the Flowering
Plants (=Angiosperms)
A flower
fl
is
i a specialized
i li d shoot,
h t adapted
d t d for
f sexuall reproduction.
d ti
A fruit develops from a flower following fertilization.
Other plants perform sexual reproduction, but do not use flowers,
and do not form fruit.
fruit
Flowers
• Zygomorphic
– One line of symmetry
• Actinomorphic
– Radial symmetry
• Perfect vs imperfect
• Hypogynous,
yp gy
Perigenous,
g
Epigenous
pg
Lychee flowers
Male
female
p
both hermaphrodidic
Fruit
• Four types
– Simple (Berry, Drupe)
• Dehiscent (legume,
(legume follicle)
• Indehiscent (achene caryopsis, nut)
– Aggregate (multiple drupes/drupelets) from a single
flower (blackberry)
– Multiple
p ((pineapple, mullberry)
y) manyy flowers per fruit
– Accessory (pome, pepo, bannana) contain tissues
derived from parts other than the ovary
Seeds
http://www.leubner.ch/anatomy.html
Seeds cont.
cont
Seedlings
• Are sensitive
to attack by
fungi insects,
fungi,
insects
bacteria etc.
• May require
breakage of
dormancy
How a seed germinates
Germinated