Botany for gardeners 2014-final notes

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© Project SOUND
Out of the Wilds and Into Your Garden
Gardening with Western L.A. County Native Plants
Project SOUND – 2012 (our 8th year)
© Project SOUND
Botany for S. CA
Gardeners
Key Botanic Concepts to
Improve Your Gardening
C.M. Vadheim and T. Drake
CSUDH & Madrona Marsh Preserve
Madrona Marsh Preserve
February 1 & 4, 2014
California – the land of extremes
 Latitude
 Elevation
 Temperature
 Precipitation
 Soil type, content
© Project SOUND
That’s part of the reason why
my have so many unique
native plants
http://mapsof.net/uploads/static-maps/california_relief_map.png
Botany: the study of plants (huge subject area)
I. Names, descriptions and taxonomy
II. Seeds
A. How they develop
B. Dispersal
C. Germination
III.How plants grow
IV. Water & nutrients from the
environment
© Project SOUND
Today’s talk

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© Project SOUND
Hollyleaf Redberry – Rhamnus ilicifolia
© 2003 BonTerra Consulting
Scientific names: why do we need ‘em?
 They are (or at least should be)
universal
 They are unique to a given taxon –
unlike common names like ‘Wild
pea’ or ‘Wild sunflower’
 The name sometimes describes
characteristics of the plants
[ilicifolia = holly-like leaves] or
honors the person who discovered
them
 The name (should) reflect the
evolutionary relationships
between it and other taxa
© Project SOUND
Rhamnus ilicifolia
© 2006 Steve Matson
Taxonomy & Systematics: grouping & naming
 Taxonomy: science that finds,
identifies, describes, classifies,
and names plants
 Three goals:
 Identification : identifying an
unknown plant by comparison
with previously collected
 Classification: placing known
plants into groups or categories
to show some relationship.
 Description : formal description
of a new species, usually in the
form of a scientific paper
 Systematics: the science of
relationships between plants
and their evolution, especially
at the higher levels
 Classical (morphological)
systematics – based on
similarities in plant physical
characteristics (how plant
looks; chemical similarities;
etc.)
 Molecular systematics –
based on similarities in
genetic material
© Project SOUND
The two are highly interrelated – both aim to better understand and
reflect the true relationships between different plants
© Project SOUND
Kingdom Plantae – Plants
Subkingdom Tracheobionta – Vascular plants
Superdivision Spermatophyta – Seed plants
Division Magnoliophyta – Flowering plants
Class Magnoliopsida – Dicotyledons
Subclass Rosidae
Order Rhamnales
Family Rhamnaceae – Buckthorn family
Genus Rhamnus L. – Buckthorn
Species Rhamnus ilicifolia Kellogg – Hollyleaf redberrry
© 2005 James M. Andre
http://seinet.asu.edu/images/vasc_herbarium_images/Rhamnaceae/photos/Rham_croc_SL_N0086.jpg

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Resources to help the confused gardener
 USDA Plants Database:
http://plants.usda.gov/java/
© Project SOUND
The importance of higher taxa: insight
 Family Rhamnaceae
 Mostly trees/shrubs
 Simple leaves, with stipules
 Flowers usually small, inconspicuous
[exception: Ceanothus spp.]
 Fruits are mostly berries, fleshy
drupes or nuts – mostly dispersed
by mammals and birds.
 Chiefly used as ornamental plants
and as the source of many brilliant
green and yellow dyes
© Project SOUND
© 2003 BonTerra Consulting
© 2005 James M. Andre
The importance of higher taxa: insight
 Genus Rhamnus
 Common name: Buckthorn
 Usually deciduous – CA has evergreen species
 Fruit: berrylike, fleshy (edible?)
 Wide light tolerance range
 Generally drought tolerant once established
 May be slow to get started – then easy to grow
 May cause mild dermatitis
 Medicinal: prepared bark - purgative; laxative
 Invasive potential: in Eastern U.S., exotic
buckthorns (R cathartica; R. frangula) tend to
form dense, even-aged thickets, crowding and
shading out native shrubs and herbs
 California members:
 Rhamnus (now Frangula) californica – CA
Coffeeberry
 Rhamnus crocea – spiny redberry
© Project SOUND
Spiny redberry
Rhamus crocea
http://biology.csusb.edu/PlantGuideFolder/RhamnusCrocea/RhamnusCroceaPage.htm
© 2002 Kristiaan Stuart
© Project SOUND
The scientific name
 The generic name is listed first
(with its first letter capitalized),
followed by a second term, the
specific name (or specific
epithet) and the name(s) of the
first namer
 International Code of Botanical
Nomenclature – specifies the
format and conventions
 U.S. Integrated Taxonomic
Information System (ITIS) -
facilitates sharing biologic info.
by providing a common framework
for taxonomic data
 Sometimes regional experts don’t
agree with ITIS
Hollyleaf redberry
Rhamnus ilicifolia Kellogg

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Calflora database: CA plants (native & not)
© Project SOUND © Project SOUND
What is a species?
 Some definitions of species
 Biological Species Concept - they cannot
interbreed & produce viable offspring;
interbreeding studies
 Morphospecies Concept - they are
different morphologically and do not
come in contact for interbreeding
 Genetic Species Concept – still working on
this – how similar must they be to
constitute a species?
 Practical definition - Practically,
biologists define species as populations of
organisms that have a high level of
genetic similarity.
 The field of taxonomy is changing with
our increasingly sophisticated tools
Lyonothamnus floribundus
ssp. aspleniifolius
Lyonothamnus floribundus
ssp. floribundus
California (and other biologic ‘hotspots’)
present more challenges
 Lots of geographic/topographic
variability
 Relatively ‘rapid’ environmental
changes (since last Ice Age)
 Lots of geographically separate
populations – are in the process of
diverging
 In other words, speciation is a
‘work in progress’
© Project SOUND
http://biology.csusb.edu/PlantGuideFolder/RhamnusCrocea/RhamnusCroceaPage.ht
m
Rhamnus ilicifolia
Rhamnus crocea
Why all the current taxonomic/systematic
arguments about CA native plants?
 When two species have fully diverged from a common ancestor
they will possess the properties commonly associated with
independent species:
 reproductive incompatibility
 distinctive morphology
 ecological uniqueness.
 During the process of divergence, these properties are
gradually acquired in a continuum spanning thousands of years.
 When two lineages are in the early stages of speciation it is
difficult for biologists holding different species concepts to
agree on when there has been enough divergence to declare
them as different species.
© Project SOUND

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What’s a CA native plant gardener to do?
 Keep calm – this period of rapid
change will end
 Nurseries will likely know plants
by both old and new name
 Use on-line sources
 Native Plants at CSUDH
 Scientific name - Scientific name
key
 Common name - Scientific name
key
 USDA Plants database
 Calflora database
© Project SOUND
http://www.zarachiron.com/2013/06/spanish-men-a-cultural-enigma/
Native Plants at CSUDH -
http://nativeplantscsudh.blogspot.com/
© Project SOUND
Use the ‘pages’ on left of screen
© Project SOUND
Name to name lists are here
The PLANTS
database

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Implications of plant taxonomy/systematics
for the gardener
 Precise, scientific names are
important:
 For scientists – including biomedical
scientists working with plant-based
medicinal chemicals, insecticides, etc.
 For you as a gardener – so you
purchase the plant whose
characteristics you want
 Plant systematics provides insights
 Understanding basic characteristics
of groups – requirements,
susceptibilities, toxicities
© Project SOUND
Rhamnus ilicifolia
Implications of plant
taxonomy/systematics for the gardener
 Conservation – importance
of conserving local
endangered species in
gardens, seed banks, etc.
 Choice of appropriate plant
species – esp. if cross-
pollination danger [Salvias;
Buckwheats]
 Evolution in the garden
 ‘garden-friendly’ cultivars
(including novel hybrids)
 Selection and climate
change
© Project SOUND
Plant anatomy and morphology:
describing plants
© Project SOUND
Describing plants: what do those terms mean?
 Stem: bark gray; branches
stiff, generally ascending;
twigs glabrous to finely hairy.
 Leaf: evergreen; petiole 2–10
mm; blade 20–40 mm, ovate to
round, thick, glabrous
adaxially, glabrous or hairy,
flat to concave abaxially, base
rounded, tip obtuse, rounded,
or widely notched, margin
entire, irregularly toothed,
or prickly, veins prominent or
not.
© Project SOUND
http://www.calflora.net/bloomingplants/hollyleafredberry.html

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Describing plants: simple leaves
 Basic anatomy
 Petiole
 Blade
 Stipule
 Veins
 Midrib
 Veins
 Shape terminology
 Overall shape
 Blade tip
 Blade base
 Margins
© Project SOUND
http://www.robinsonlibrary.com/science/botany/anatomy/leafparts.htm
Margin
Blade tip
Base
Simple vs.
compound leaves
 Clues:
 Look for an axillary bud (just
above the midrib)
 Look at old (or recently fallen)
leaves – the petiole separates
cleanly from the branch (due to
an abscission layer)
 Use plant Family traits – [Pea
family (Fabaceae) usually have
compound leaves]
© Project SOUND
http://www.robinsonlibrary.com/science/botany/anatomy/leafparts.htm
Describing plants: leaf shapes
© Project SOUND
http://www.clemson.edu/extfor/publications/bul117/characteristics.htm
toothed
http://www.nbh.psla.umd.edu/guides/appendix2.html
Describing plants: what do they mean?
 Stem: bark gray; branches
stiff, generally ascending;
twigs glabrous to finely hairy.
 Leaf: evergreen; petiole 2–10
mm; blade 20–40 mm, ovate to
round, thick, glabrous
adaxially, glabrous or hairy,
flat to concave abaxially, base
rounded, tip obtuse, rounded,
or widely notched, margin
entire, irregularly toothed, or
prickly, veins prominent or not.
© Project SOUND

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Botanical terms/concepts & plant identification
 Some excellent resources written
specifically for the gardener
 These 3 books are very good
© Project SOUND
Help with terminology
 Books
 Allaby, M : Oxford Dictionary
of Plant Sciences
 Beentje, H : Kew Plant
Glossary - an illustrated
dictionary of plant terms
 On-line:
 Several good resources – good
for gardeners
© Project SOUND
 We’ve tried to make using
on-line resources easier by
bringing together the best
in one place – ‘Native Plants
at CSUDH’
Let ‘Native Plants at
CSUDH’ help
© Project SOUND
The ‘Pages’ on the left of the screen provide helpful links to the Project
SOUND/Out of the Wilds plant lists(under ‘Plant Lists’), gardening
information sheets & plant photos (under ‘Gallery of Native Plants’)
Gallery of Native Plants – Native Plants at CSUDH
© Project SOUND
There alphabetical name lists:
• Scientific name to current sci name
• Common name to scientific name

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Native Plant Gallery – Native Plants at CSUDH
© Project SOUND
Click ‘Save’ – then choose to download
or save. You’ll be able to click on links
Help make the
‘Gallery’ even better
© Project SOUND
Send us your pictures of CA native
plants growing in garden settings
Native Plants at CSUDH
http://nativeplantscsudh.
blogspot.com/
© Project SOUND
Just search ‘native plants
at csudh’ with your favorite
browser
We’re very familiar with the life stages of
animals
© Project SOUND
http://www.baby-connect.com/
http://onlinebusiness.volusion.com/articles/seniors-online/
http://fastfoodies.org/movie-food/elderly-people-on-computer/

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Plants have similar – but different – life stages
 Fertilization
 Embryogenesis/seed formation
 Seed germination/early growth
 Juvenile growth (vegetative)
 Mature growth (vegetative)
 Flowering/Fruiting/seed
production
 Senescence
 Death
http://ww2.valdosta.edu/~ckbeck/ebook.html
Describing plants: what do they mean?
 Inflorescence: 1–6-flowered,
generally glabrous; pedicel 2–4 mm.
 Flower: generally unisexual;
hypanthium ± 2 mm wide; sepals 4;
petals 0.
 Fruit: 2-stoned, 4–8 mm, red.
© Project SOUND
Mark W. Skinner @ USDA-NRCS PLANTS Database
http://www.researchlearningcenter.org/bloom/species/Rhamnus_ilicifolia.htm
Inflorescence: grouping/arrangement of flowers
© Project SOUND
http://www.flowers-gardens.net/gardens/types-of-inflorescence.html
Wikipedia has a very good coverage of inflorescence terms
Flowers are leaves specialized for reproduction
 Calyx (whorl of Sepals) –
protect/attract
 Corolla (whorl of Petals) –
attract
 Stamen – male sex parts
 Filament
 Anther – produces pollen
 Pistil – female sex parts
 Stigma – receives pollen
 Style – channel
 Ovary – contains eggs
which become seeds
© Project SOUND
A ‘perfect’ flower – has all the parts
http://scienceblogs.com/pharyngula/2006/11/20/mads-boxes-flower-development/

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How does the pollen get to the stigma?
 Falls on it
 Physical agents
 Wind
 Water
 Biologic agents (Mother
Nature’s cupids)
 Bees
 Flies
 Butterflies/moths
 Other insects
 Hummingbirds
 Bats
 Other animals
© Project SOUND
Take-home messages: pollination
 Getting the pollen to the egg isn’t
easy if you’re a plant – and you
usually need a little help
 The lives of plants and their
pollinators are in intimately
intertwined
 Plants and animal pollinators have
evolved together (co-evolution).
 Plants usually don’t waste energy on
things they don’t really need – the
color/scent etc. are there for a
reason
© Project SOUND
What are the likely pollinators of
Hollyleaf redberry?
Pollination and
Fertilization
http://www.educationcaribbean.com/resources/encyclopaedia/science/plants.asp
What does it take to form a seed?
© Project SOUND
http://www.bio.miami.edu/dana/226/226F09_4.html

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The unwritten goal of all living things:
reproduce and disperse
© Project SOUND
That’s how species survive
through time
Why the need to disperse?
 To colonize new areas – which may have better resources or
other advantages
 To increase genetic diversity within the species or population –
novel combinations that may confer an advantage
© Project SOUND
 To decrease
unhealthy
competition (for
light, water,
other resources)
http://ebd10.ebd.csic.es/ebd10/Dispersal_and_gene_flow_files/shapeimage_2.png
Dispersal is relatively easy if you have
legs or can swim
© Project SOUND
http://www.immortalhumans.com/early-man-had-the-same-life-span-as-neanderthals/
Seed dispersal: traveling through space
 Dropping to the ground
 Catapulted from the dry seed
capsule (fruit)
 Carried by physical agents
 Floating on the wind
 Carried by water
 Carried by living agents
 Hitchhiking on animal fur, feathers
or feet
 Travelling through a bird or animal
for eventual deposition
© Project SOUND
http://science.psu.edu/news-and-events/2010-news/Carlo2-2010

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Clues to dispersal: often easy to read
© Project SOUND
Box Elder – Acer negundo
Jojoba - Simmondsia chinensis
http://www.arizonensis.org/sonoran/places/cavecreek.html
 Size/weight
 Flight/hitchhiking appendages
 Inside a fleshy fruit
 Characteristics of pod/capsule
CA poppy
Others are a little more difficult
© Project SOUND
http://www.arizonensis.org/sonoran/places/cavecreek.html
Yellow Paloverde – Parkinsonia microphylla
 Pea family
 Large, heavy seeds
 Characteristic pod
 Plant distribution in landscape
 Along seasonal streams
 Seeds distributed by water
 Effective for dispersing large,
heavy seeds over wide area
 Ensures that seeds will be
dispersed at a time conducive
to germination
 Ensures that plants grow
where best suited to survive
Seed distribution implications for gardeners
 Some seeds are born to naturalize:
small seeds [annual wildflowers]; wind-
born seeds [Milkweeds]
 Plant species with fleshy fruits and
you’ll attract fruit-eating birds &
other dispersal agents
 Remember, some seeds are meant to
be carried in animal fur (clothing,
etc.) [some grasses; cocklebur]
 Plants with unusual dispersal
mechanisms may require special
treatments to encourage them to
germinate
© Project SOUND
http://dendro.cnre.vt.edu/dendrology/syllabus/fact
sheet.cfm?ID=491
Yellow Paloverde
Parkinsonia microphylla
A seed is somewhat like a ‘manned’
space capsule
 A ‘capsule’ with a protective covering
 Containing
 A living organism: so dry that it’s in a state of suspended
animation
 Provisions for the journey & for re-settlement
 Traveling through space & time
© Project SOUND
http://millburyschools.sharepointsite.com/elmwood/lhippert/Picture%20Library74/Forms/DispForm.aspx?ID=3&RootFol
der=%2Felmwood%2Flhippert%2FPicture%20Library74%2F1 http://www.gijoecanada.com/index.php?main_page=product_info&cPath=71_76_
90&products_id=404

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The consequences of seed travel through
time and space
 Must have adequate protection – for
wide range of possible conditions
 Must have adequate provisions
 Must provide everything needed to
keep the ‘living being’ alive until it
reaches it’s final destination
 Must keep the weight/size down
(usually – depends on dispersal)
 Must not open the hatch-door until
it’s reached its destination and
conditions are ‘favorable’
© Project SOUND
http://www.ehow.com/info_8547249_stages-plant-reproduction.html
The mighty seed
© Project SOUND
http://generalhorticulture.tamu.edu/HORT604/LectureSupplMex07/HORT604Mexico2007.htm
 Seed coat (testa) – protective coat
 Cotyledon/Endosperm - food source
 Embryo
 Radicle (embryonic root)
 Hypocotyl/epicotyl (embryonic root/shoot)
 Plumule (embryonic shoot/leaves)
http://www.cmg.colostate.edu/gardennotes/137.html
monocot seed (corn)
Overview of Embryonic Development
http://www.pnas.org/content/107/18/8063/F1.expansion.html
A completely mature, dry seed remains in
a state of suspended animation…
sometimes for a very long time
© Project SOUND

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Seed germination: complex process
 What we’re interested in today is how does a seed begin
the germination process – and what does it need to survive
as a seedling
© Project SOUND
Koning, Ross E. 1994. Seeds and Seed Germination. Plant Physiology Information Website.
http://carlsbadcommunitygardens.org/2013/04/2nd-annual-carlsbad-seed-swap-at-the-smerdu-community-garden/
You may have noticed that fresh seeds
often germinate more easily
© Project SOUND
…but most seeds don’t
germinate prematurely. Why?
http://viviparouscapsicumfruitescens.blogspot.com/
The timing of germination is critical
 Must be adequate resources
for the seedling to survive:
 Water
 Light
 Nutrients
 Possibly other
 Must not have future
conditions that will kill a young
seedling (seedling stage is the
most vulnerable life stage):
 Too low or too high
temperatures
 Drought
 Fire
© Project SOUND
California poppy - Eschscholzia californica
Immediate
future
Slightly
longer range
Plants have developed several strategies
to prevent premature germination
 Seed quiescence : delay
germination because the external
environmental conditions are not
right : too dry or warm or cold for
germination [most annuals; many
fresh woody plant/perennial seeds]
 Seed dormancy : seed is unable to
germinate in a specified period of
time under environmental
conditions that are normally
suitable for the germination of the
non-dormant seed [many woody
plant species normally facing
challenging conditions]
© Project SOUND

2/2/2014
16
Several different processes: separate but
often interrelated
 Seed germination:
 Depends on both external (environment) and internal (embryonic)
conditions [seed maturity]
 Environmental: water, oxygen, + temperature, light
 Seed quiescence:
 Depends on factors in the seed itself – ‘suspended animation’
 Released when proper conditions for germination are present
 Seed dormancy:
 Depends on factors within the seed itself (but may require
environmental cues that promote it)
 Released by exposure to proper environmental conditions (the
‘triggers’) which ‘break’ dormancy and allow germination
 Germination will not occur unless dormancy is broken
© Project SOUND
Quiescence: a temporary hold on germination
 Often due to seed dehydration
 Seeds in state of ‘suspended
animation’ ; ready to germinate
once environmental conditions
change for the better
 The seed reaches soil
 The first rain
 The temperature warms up
 Etc.
 The risks associated with
quiescence strategy: premature
germination if conditions again
change for the worse [hot, dry
conditions after the first rain]
© Project SOUND
ZZZzzzzzz
http://unrealnature.wordpress.com/2008/10/27/some-assembly-required/
Dormancy: longer term strategy
 Is a characteristic of the seed itself (not the environment);
some seeds [those from tropical regions; typical garden plant
seeds] exhibit no dormancy
 Some CA native seeds are dormant when they leave the plant
(primary dormancy) – insures dispersion will occur prior to
germination
 Others only become dormant only when they experience
unfavorable conditions (too dry; too hot or cold) – secondary
dormancy
 Difference between fresh seeds and ‘older’ seeds is usually
explained by secondary dormancy
 Dormant seeds will not germinate unless dormancy is ‘broken’
© Project SOUND
Germination and dormancy are two
different processes
© Project SOUND
http://www.rtbg.tas.gov.au/index.aspx?base=332

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The life cycle of seeds: mediterranean climates
© Project SOUND
http://www.rtbg.tas.gov.au/index.aspx?base=299
Why is seed dormancy important?
 Ensures time for seed dispersal
 Prevents germination during unsuitable ecological
conditions
 Enables seeds to survive short periods of favorable
conditions; when germination stimulating factors are
present, but prevailing conditions are not suitable for
subsequent seedling growth and plant development.
 Prevents germination of all the seeds at the same time.
The staggering of germination safeguards some seeds
and seedlings from suffering damage or death from
short periods of bad weather, transient herbivores, etc
© Project SOUND
In other words, the dormancy evolved as a mechanism to
postpone germination until a time and place that not only
supports germination, but also maximizes seedling
establishment and growth.
Seed dormancy: many variations
 Seed coat-imposed dormancy [AKA Exogenous/External
dormancy] - caused by an impermeable seed coat
 Embryo-imposed dormancy [AKA Physiological/endogenous/
internal dormancy] – caused by the embryo itself; prevents
embryo growth and seed germination until chemical changes
occur within the embryo
 not due to any influence of the seed coat or other surrounding
tissues
 most abundant form of seed dormancy in angiosperm
 thought to be due to the presence of inhibitors, especially ABA, as
well as the absence of growth promoters, such as GA (gibberellic
acid).
 Combinations – why it’s sometimes hard to determine the
factors needed to ‘break dormancy’ in a given species
© Project SOUND
Seed coat-induced dormancy: several
common mechanisms
 Seed coat prevents water or
oxygen uptake: [waxy coatings;
special layers in seed coat that
block water]
 Hard seed coat prevents embryo
from growing/emerging [coat must
be softened/broken by exposure to
stomach acids; mechanical means]
 Seed coat contains growth
inhibitors [must be leached away
be repeated rinsing; exposure to
chemicals that break down the
inhibitors]
© Project SOUND

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Seed coat-induced dormancy: breeching
the seed coat
 Seed coat must be broken down to allow
entry – embryos will germinate readily in the
presence of water and oxygen once the seed
coat and other surrounding tissues are either
removed or damaged.
 Is usually all or none: once seed coat is
breeched there’s no turning back – so timing
is critical
 Typically found in species from the families
Fabaceae, Malvaceae, Chenopodiaceae, and
Liliciae
© Project SOUND
http://www.seedsplants.kimeracorporation.co
m/articles/19-come-seminare-.html
Scarification: breaking/fracturing seed
coat to facilitate water/gas uptake
 Mechanical : tumbling, abrasion,
‘nicking’, pounding etc.
 Chemical : usually involves acid
treatment like concentrated H2S04
(sulfuric acid), other acid treatments
 Physical : hot water treatment; other
heat treatment (burning)
 Soaking/leaching : some seeds
© Project SOUND
http://www.organicgardening.com/learn-and-grow/pretreatments-slow-
germinate-seeds
http://mpgranch.com/staff-blogs/tales-of-a-
transplant/scarification-and-stratification.aspx
Treatments to break embryo-induced
dormancy vary by plant
 Common requirements/
treatments
 Drying [after-ripening]
 Low temperatures [stratification]
 Alternating soaking/drying
 Applied by mother nature – or by
the propagator
 Clues from the native
environment of the plant
© Project SOUND
Hollyleaf redberry grows
in dry places, often with
colder winters – may
require stratification
Chilling (stratification): exposure to cold-
moist conditions
 Prevents temperate climate seeds
from germinating until the spring
 Temperatures: 0-10° C (32-50° F)
 Time: usually 1-3 months; seed
supplier may specify
 Seeds need to be fully hydrated –
stratify in moistened vermiculite
or moist paper towel/coffee
filters in refrigerator
 Need access to oxygen (air)
© Project SOUND
Garden collected seed – may
want to wash first in mild (5%)
bleach solution to prevent fungal
contamination

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19
Some environmental conditions that break
embryo-induced dormancy in CA native plants
 Drying [after-ripening - grasses]
 Low temperatures [stratification]
 High temperatures [heat stratification]
 Light (or dark) exposure
 Fluctuating temperatures (repeated heating and cooling over
many months-years),
 Fire/smoke chemicals
 Freezing/thawing (may require cycles)
 Passage through the digestive tracts of animals/birds
 Removal/breakdown of fleshy fruit
 Acid treatment
© Project SOUND
Important points about CA native seeds
 They differ in the amount of stored food
 Small amounts - must start producing quickly
 Large amounts – live off stored ‘food’ for a while
 They differ in the composition of their seed
coat –some are harder than others
 They germinate in response to cues (all seeds)
 Water – cue + softens coat (all plants)
 Oxygen
 Light (small seeds)
 +Temperature
 Some seeds are actually dormant until
‘awakened’ by environmental exposures
© Project SOUND
Implications for gardeners: seeds
 Storage:
 Store seeds cool and dry
 In general, smaller seeds have
shorter ‘shelf-life’ than larger
seeds
 Planting:
 Know if your seeds need pre-
treatment to break dormancy
 Seed company instructions
 On-line
 Inference: place of origin;
taxonomic
 Plant seeds at the correct
depth – some need light to
break dormancy
© Project SOUND
http://www.sierraclubgreenhome.com/go-green/landscaping-and-outdoors/organic-seeds/
Once seeds have germinated,
be sure to keep them adequately
watered – very vulnerable to
dehydration
Be patient: just because you don’t see
anything, doesn’t mean nothing is
happening
 Root development may occur
before shoot development –
particularly in large seeds
[acorn]
 Dormancy due to germination
inhibitors may take some time
 Cycles of hot and cool
 Cycles of wet and dry
 Many ‘washings’ to leach away
or chemically modify the
inhibitors
© Project SOUND
http://www.roguehydro.com/germinating-your-seeds/

2/2/2014
20
How do plants grow? By adding modules
 All plants are based on same
basic pattern:
 Shoot system
 Main stem
 Laterals (branches)
 Root system
 Primary root
 Lateral roots
© Project SOUND
http://leavingbio.net/flowering%20plants.htm
http://en.wikipedia.org/wiki/Plant_stem
Shoot and root elongation and development
is segmental in plants
 Phytomere: developmental
segment for shoot (shoot
module) or root (root module)
 Phytomeres develop from
unspecialized cells in special
areas of the plant – the apical
meristems
Plant meristems: the plant’s ‘fountain of youth’
 Apical meristems (shoot and
root)
 At the shoot and root tips
 Give rise to the shoot or
root modules
 Result in elongation
 Axial meristems
 Located at/near a node
 Give rise to branches
 Lateral meristems
 Located internally in
shoots/branches
 Responsible for growth in
girth
© Project SOUND
http://vannocke.hrt.msu.edu/plb865/31oct/meristems.html
What do the meristems look like?
 Central area with lots of simple cells
 Surrounded by area of smaller cells
(due to cell division)
 Cells are more specialized looking
(and larger) the further away from
the meristem they are
© Project SOUND
http://www.sbs.utexas.edu/mauseth/weblab/webchap6apmer/6.1-1.htm
http://mrzacbio.blogspot.com/

2/2/2014
21
All cells, tissues & organs arise form cells
in the apical meristems
 Can traced origins back to
the meristems
 “Fate maps” can be drawn to
trace the evolution of
developing tissues
 Apical meristem contains
 Concentric rings of cells
 Outer-most rings
(segments) form lowest sets
of leaves/stem segments
 Pattern of development is
somewhat like the water
coming out of a fountain
Phyllotaxy – the arrangement of
leaves on the stem
 Is genetically determined – that’s
why it’s often used in taxonomy &
plant keys
 Is determined by how much each new
segment is offset around the stem
© Project SOUND
http://www.ecotree.net/fall_2011.shtml
http://everydayfibonacci.tumblr.com/
http://www.biologie.uni-hamburg.de/b-online/virtualplants/ipi_ic2.html
Leaf arrangement/position (in relation to
others) – phyllotaxy
© Project SOUND
©2009 Robert Steers
Why do plants grow (at least in part) by
adding new segments?
 Because that’s how they evolved
 Efficiency: particularly in an ever-
changing environment
 Redundancy/backup : plants need to
be able to regenerate lost parts
 As a consequence of a need for rigid
structure
© Project SOUND

2/2/2014
22
Plant cells are a little different from our cells
 One of the big differences is
that they form cell walls
 Primary cell wall
 Formed first – just inside the
cell (plasma) membrane
 Strong but flexible
 Allows for growth in certain
directions (for example, cells can
elongate)
 Secondary cell wall
 Formed inside the primary cell
wall
 Very strong; inflexible
 No growth after secondary cell
wall is formed
© Project SOUND
http://acseenotes.wordpress.com/2011/03/07/cytology/
What the heck! Why would plants do that?
 Strong cell walls give plants the structure needed to grow tall
 But plants still need to keep growing
 Solution: add new segments on top of the old – requires apical
meristems © Project SOUND
http://www.doitpoms.ac.uk/tlplib/wood/structure_wood_pt2.php
http://montessoriworkjobs.blogspot.com/2011/10/human-skeleton.html
Consequences of sedentary life: scary!
 Plants need to keep ‘rejuvenating’
themselves throughout life –
roots and shoots
 Therefore they continue to grow
throughout their lives –
sometimes for 1000+ years
 In order to grow they need
functional meristems [plant stem
cells]
 But what happens when
something happens to an apical
meristem (disease; herbivory)?
© Project SOUND
Ancient (senescent) Bristlecone pine
Fortunately, plants have a backup system
 In most plants – most of the time
– segments are added by the
apical meristems
 But there are ‘backup meristems’ –
the axial meristems
 Development of axial meristems is
limited to a degree by the
functional apical meristem –
produces an inhibitory hormone
 Once the apical meristem is gone,
the axial meristems take over the
job of elongation
© Project SOUND
http://vannocke.hrt.msu.edu/plb865/31oct/meristems.html

2/2/2014
23
The shapes of plants
http://www.wildmanstevebrill.com/JPEG'S/Plant%20Image
s/Chicory.Rosette.jpg
http://www.unc.edu/~hallman/cookbook/pumpkin-vine.jpg
http://www.co.columbia.wi.us/dept/lwcd/images/tree.gif
http://www.houstonrose.org/ghbush.jpg
Stem elongation and control of the number of main shoots
The length of the internode is one
determinant of plant shape
© Project SOUND
http://www.doyletics.com/digest51.shtml
 The main difference between the shape of a cabbage and a
Southern honeysuckle vine is the length of the internodes
The length of the internode: genetics and
environment
© Project SOUND
©2009 Robert Steers
Southern honeysuckle - Lonicera subspicata
Turkish rugging - Chorizanthe stacticoides
Take home messages
© Project SOUND
 The basic structure (growth
pattern/shape; mature size) is
genetically determined.
Choose plants accordingly
 But…plants have enough
flexibility programmed in to
allow them to modify their
shape based on conditions:
 Limited water/nutrients –
shorter internodes
 Limited light – longer
internodes as plant ‘reaches
for the sun’

2/2/2014
24
But internode length doesn’t explain all of
the shape variability
© Project SOUND
Torrey pine - Pinus torreyana Lemonadeberry – Rhus integrifolia
Apical dominance:
not all or none
 Several plant hormones
involved – degree of apical
dominance depends on balance
of these
 Degree of apical dominance is
genetically determined – that’s
why a pine tree has a strong
central leader and a shrub has
many equal ‘stems’
 You can (sometimes) make a
strongly dominant form more
shrub-like; it’s more difficult
to go the other way around
© Project SOUND
http://plantphys.info/apical/apical.html
http://www.tutorvista.com/content/biology/biology-iv/plant-growth-movements/growth-
regulators.php
Tip-pruning (‘pinching’) removes apical
dominance creating a ‘bushier’ plant
 Just remove the tip – don’t need to take much
 Must be done during periods of active growth
 Must do repeatedly for best effects – new side branches
will also exhibit apical dominance
© Project SOUND
http://www.studyblue.com/notes/note/n/botany-exam-3/deck/1607515
How far back can I safely tip prune/ prune to
head back?
 Lateral buds have an age – oldest
at the base of a stem/trunk and
youngest at the top
 How long do lateral buds retain the
ability to grow? Alas, no one
answer.
 But there are some rules of thumb:
 Generally - but not always – lateral
buds in older woody parts of stems
have decreased/no growth
potential
 Generally – but not always – buds in
semi-soft or soft wood (younger
parts of stem) will grow
© Project SOUND

2/2/2014
25
Take home messages: pruning/shaping
 When shaping woody plants, start
when plants are young
 Know taxa that require careful
pruning:
 Ceanothus spp
 Arctostaphylos spp
 Salvia spp
 Pinus spp
 Prune ‘difficult’ species either:
 During growth period (when wood
is still semi-soft) for tip-pruning
 When you can clearly apply the
‘leave 3-4 leafing buds’ rule
© Project SOUND
What ‘materials’ do plants need from their
environment?
 Sunlight
 Photons of light (energy for
photosynthesis)
 Air
 Oxygen (to break down stored
food)
 Carbon dioxide (CO2) (for
photosynthesis)
 Soil/medium
 Water
 Nutrients (minerals/
fertilizer)
© Project SOUND
http://www.nelsonthornes.com/secondary/science/scinet/scinet/plants/nutri/c
ontent.htm
How do these move around the plant?
Roots (root hairs) are where water and
minerals enter the plant
 Good soils contain what
plants need:
 Water
 Mineral nutrients
(dissolved in the soil water)
 Oxygen (needed by the
roots so that they can
obtain energy & perform
their functions)
© Project SOUND
http://www.aaronthomaslandscapes.com/blog.html
The importance of soil water/oxygen balance
 Too much water
 Root oxygen depleted – decreased uptake of water, minerals
 Too little water
 Roots cannot uptake water or dissolved minerals
© Project SOUND
http://www.stevenswater.com/articles/irrigationscheduling.aspx
That’s why the symptoms or over- and under-watering are the same

2/2/2014
26
Root characteristics: especially important
with CA native plants
 Coastal sage scrub shrubs
 Primarily fibrous roots
 Primarily shallow roots (< 3 ft)
 Root:shoot ratio increases with
water & nutrient stress
 Chaparral shrubs
 Combination of deep and
shallower roots
 Root growth in spring/ summer
 Root:shoot ratio increases with
water & nutrient stress
© Project SOUND
http://www.rmrs.nau.edu/watersheds/highlands/vegetation/chaparral/chpla
ntwater.html
Individual species have
characteristic root growth patterns
Root characteristics of some common CA
native shrubs
© Project SOUND
Use root characteristics to choose the
proper plant – and treat it well!
 Taproot
 Likely very drought-tolerant
 Plant is out young – don’t move
 Not for containers
 Fibrous roots
 Look for depth characteristics
 Shallow
 may need occasional or regular
water
 Take care when digging
 Good for containers
 Good choice for slopes, banks
 Lignotuber
 Fire-adapted; may require occasional
rejuvenation
© Project SOUND
http://nativeplants.msu.edu/getting_started/how_to_plant/establishment_
of_rooted_plant_material
We’ll discuss roots more next month
© Project SOUND

2/2/2014
27
Development of the
vascular system
 New segments of vascular system are added by apical meristems
 New layers of vascular tissue in older segments are added by
lateral meristems (called vascular cambium)
http://cnx.org/content/m43140/latest/
http://cnx.org/content/m47400/latest/?collection=col11569/latest
© Project SOUND
http://www2.puc.edu/Faculty/Gilbert_Muth/phot0010.jpg
http://sci.waikato.ac.nz/farm/content/plantstructure.html
 Benefits
 Two systems in close
physical proximity – key to
water/nutrient movement
 Easy access for loading &
unloading throughout the
plant
 New tissue can be added –
even in woody parts
 Somewhat protected
(fiber cap; bark)
 Drawbacks
 Vulnerable location
Location of
vascular tissues
Take-home messages: plant vascular system
© Project SOUND
 Soil water status is important not only
for plant water needs, but also for
mineral nutrition – more next month
 Plant vascular tissues move all sorts of
vital things around the plant body – an
intact system is a must
 Vascular tissues are vulnerable:
 Girdling
 ‘sucking’ insects [aphids]
 Transport of toxins
http://caseytrees.org/blog/summer-tree-care-making-gardening-and-lawn-
care-safe-for-trees/
https://extension.umd.edu/learn/homeowner-landscape-series-common-
cultural-and-environmental-problems-landscapes-hg201
http://cnx.org/content/m47400/latest/?collection=col11569/latest
We hope you look at plants differently
© Project SOUND

2/2/2014
28
 Read a botany book
 Use on-line resources – and refer others to them
 Come back next month when we consider the effects of
climate change
© Project SOUND

Botany for gardeners 2014-final notes

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