Final: Plant Diversity & Ecology

Gymnosperms

Cycaadophyta (Cycads), Ginkophyta (Ginkgos), Pinophyta (Conifers), Gnetophyta (Gnetophytes)

Exposed seeds

What does gymno mean? What does sperm mean?

naked, seed

Gymnosperm seeds are surrounded by a seed coat

integument

Gymnosperm life cycle

Female gametophyte (seed) receives nutrition from and is protected by the sporophyte until it is mature

Are cycads threatened or abundant?

All therented or endangered however was abundunt and dierse during the dinosaur ages

Are cycads dioecious or monoecious

dioecious

Cycads have large or small cones? And what are they called?

large cones (Strobili)

cycads leaf morphology

pinnately compound

Cyads are distributed mostly in

sub-tropics and tropics (1 native to South Florida)

Cyads are pollinated by

Beetles

Ginkgos are ____ on the planet

oldest plant species

Ginkgos are dioecious or monoecious

dioecious

are ginkgos deciduous or evergreen

deciduous (exposed seeds)

Ginkgo female seeds contians what acid that produces a putrid smell

Butyric acid

Ephedra stems contain the stimulant ___

ephedrine

Ephedra is dioecious or monoecious

dioecious

Ephedra is common in what habit

desert shrubs

Conifers are most common and abundant in what?

gymnosperms

What is so special about conifers?

largest, tallest, and oldest organisms

Examples of conifers

firs, cedars, cypresses, junipers, redwoods, pines, spruces, yews and hemlocks

Where is the pine family located mostly

northern hemisphere

Are pines dioceious or evergreen

evergreen

pines leaf shape

needle like

pine needles are produced on ___ called ___

short branches, fascicles

each pine bundle of needles is surrounded by

bud scales

are pines dioecious or monoecious

monoecious

pine pollen is produced by

small, ephemeral male cones

how is pine pollen dispersed

wind

seeds are produced in

larger female cones (often winged)

monoecious meaning

individual trees produce both male and female cones

female cones can mature in _ years

2

Female cone scales are

persistent, woody, may have a prickle (umbo)

umbo

prickle on female cone

_ seeds are on each pine cone scale

2

seeds have a ____ usually several times longer than the seed

membranous wing

What is the oldest tree in California

5064 years, Bristlecone Pine (Pinus longaeva)

what is the california state tree

coast redwood

what lumber is the most commercially valuable softwood

redwood (gymnosperm wood)

what type of trees are the tallest trees on earth

coast redwood (>380 feet)

what is the coast redwood distrubtion

occupy fog belt

Is Patagonian cypress abundant or threatened

threatened and rare

grasslands form ecotones with

coastal scrub, chaparral, oak woodland

grasslands are doinated by members of the grass family called

Poaceae

What are some of california’s native grasses

Small fescue, purple needle grass, melic grass

grass is herbaceous or woody

herbaceous

grass leaf arrangement

alternate, distichous

grass leaf bases form __ that wraps around stem

sheath

___ stems between solid node

hallow

leaves grow form __between the nodes

intercalary meristems

floret contain

2 bracts + flower

2 bracts =

lemma and palea, surround each flower

modified perianth (expand and push lemma and palea apart)

lodicules

Awn

a bristle on a glume or lemma

bran

pericarp + seed coat

germ

embryo

caryopsis

one-seeded dry fruit with the pericarp fused to the seed coat

pre-colonial california grasslands were dominated by

perennial bunch grasses

example of non native grasses

Wild oats, ripgut brome, italian rye grass, foxtail barley

What are some reasons of the grassland invasion by non native grasses

urban development, agriculture, overgrazing by cattle, annuals reproduce quickly, competition from invasive non-native grasses (mostly from Europe)

forbs

herbaceous non-grassy plants

vernal pools

Depressions in a flat plain underlain by a clay pan or hardpan soil layer that promotes long-term pooling of water

over time, vernal pools dry up …

exposing more and more soil in successive rings

Geophytes

Fleshy stems underground store water and energy

bulbets

some reproduce “clones” via small bulb leaves

Chaparral forms ecotones with

grasslands, coastal scrub, woodlands, and deserts

chaparral dominants most

stiffly branched evergreen shrubs or small trees

overlapping shrub canopies form a

dense, impenetrable tangle

Mature chaparral stands lack

an herbaceous understory

Shrubs have hard dense leaves

sclerophylls

sclerenchyma

Thick and leathery with internal bracing tissues

Sclerophyll Leaf: Epidermis covered with

thick waxy cuticle layer (waterproof)

Sclerophyll Leaves do not

wilt under drought conditions

chapparal with tough, leathery, and hard evergreen leaves adapted to survive dry climates, heat, and nutrient-poor soils

Scelerophylls

Chaparral Soils

Usually very low in nutrients. Often coarse and rocky, sometimes on sand, Most mineral nutrients become incorporated into stems and leaves of the shrubs

Chaparral recovery after fire

regrowth can be rapid because some plants have fire-resistant underground structures

enlarged woody base with dormant buds at soil level

Lignotubers

Pyrophytes

fire followers, A flush of herb species generally occurs in the spring growing season following a chaparral burn

what germinates after a fire

dormant seeds of fire followers

Natural selection

plants evolve traits that ensure survival in the wild

Artificial selection

traits are selected by humans to suit their needs (These traits may be detrimental to survival in the wild)

sativa rice

sticky, great for sushi, using chopsticks

indica rice

fluffy, main variety consumed in Western cuisines

top food crops globally that are grass

sugar cane, maize, rice, wheat, barley

How do pathogens get inside plants?

1. Moisture on leaves

2. Cuticle (waxy leaf coating)

3. Root hairs

How can pathogens subvert the cuticle?

1. Stomata (pores in leaves)

2. Wounds

3. Cutinase (digests wax)

4. Aphid transmission

Plant Defenses against Herbivory

• Reinforce Cuticle

• Trichomes (hairs)

• Spines, Thorns, Prickles

• Recruitment of ants

• Chemical Defenses

Secondary Metabolites

Organic compounds that are not directly involved in the normal growth, development or reproduction of plants

Secondary metabolite functions

1) Protection from herbivores and pathogens

2) Attracting pollinators