eccb 301 exam 3

diversity & evolution of plants final

caryophyllales- what kind of habitats do these species occur in?

“stressful” environments":

• deserts or arid regions: high salt, low water, xerophytes

• salt marshes

• alpine, tundra

what are some unusual adaptations of Caryophyllales?

succulence, no leaves, C4 and CAM photosynthesis, salt excretion

what are the characters shared by the "core Caryophyllales" families?

1. betalains- N containing pigments

2. free-central placentation (or basal)

3. curved embryo in ovule = campylotropous

4. pollen shed in triucleate stage vs. most common 2-nucleate

family:

• dichasium inflorescence, usually in a cyme

• leaves opposite, swollen nodes

• 5-merous flowers, calyx fixed

• corolla not fused, often lobed

• anthers of 1-2 whorls

• 1 pistol pf 2-5 carpels

• free- central or exile placentation

• capsule fruit opening by teeth or valves

Caryophyllaceae - carnation family

family:

• herbs, often halophytes or weeds, worldwide

• often secrete salt on leaves

• flowers small, bracted, congested, lacking corolla

• bi or unisexual, mono or dioecious

• fruit is 1-seeded circumscissle capsule (utricle) or basal seeded achine

• calyx is persistent around fruit

Amaranthaceae - amaranths

family:

• New World stem succulents proceed by spines

• fleshy, succulent, often epiphytes

• no leaves, except Pereskia

• spines or glochids at areoles

• hypanthium with many tepals

• epigynous flowers

• infinite stamens

• berry fruit

• placentation parietal (rare)

Cactaceae - cacti

family:

• herbs of wet or arid regions

• alternate, simple leaves at swollen nodes

• modified stipules as sheath = ocrea

• flowers congested

• basically 3 merous, tepals petaloid

• 1-seeded, 3-angled achene

• horticulturally important

Polygonaceae - smartweeds

family:

• worldwide woody family, except lowland tropics

• nutrient poor soils

• evergreen, tough, leathery leaves

• leaf margins often revolute or introlled

• sunken stomata, bottom of leaves covered with protective hairs

• calyx and corolla fused, corolla tube bell or vase shaped

• stamens are 2x number of petals

• often exhibit terminal pores for pollen release

• superior pistil but inferior in blueberries

• fruit is berry or capsule with 4-5 partitions and many seeds

Ericaceae - blueberries

family:

• 5-merous flowers; unusual peltate stigma

• insectivores

Sarraceniaceae - pitcher plants

family:

• 5-merous

• long styled and bell shaped or strongly zygomorphic

• inferior ovary forms berry

• opposite leaves

• many cultivated ornamentals

Caprifoliaceae - honeysuckles

family:

• large, economical important

• hollow stems

• dissected or compound leaves that are strong sheathing

• flowers small in umbels, often compound

• female flowers often along edge of each umbellet

• 5 merous, no corolla tube

• inferior gynoecium of 2 carpels separating at maturity

• SCHIZOCARP

Apiaceae - umbels (dill, carrots, celery)

family:

• milky latex commonly poisonous

• 5-merous

• left contorted perianth

• 2 separate carpels- follicles

• pollen presentation- style plunger

• 5 stamens begin to be connivent

• pollinia

• corona

• more seeds with tufts of hairs

• stamens fuse to each other and to style region- gynostegium

Apopcynaceae - milkweeds

what is a gynostegium?

when stamens fuse to each other and to style region

what are pollinia?

masses of pollen grains found in orchids and milkweeds, designed to be transferred as a single unit by pollinators

what is the corona (hood and crest)?

hood + crest

petal-like or crown-like structures between the petals and stamens

describe “Las Vegas” pollination strategy- pros and cons

risky, but when occurs, ∞ ovules are fertilized. few follicles are produced per plant. note seeds with coma attached for wind dispersal

family:

• opposite (whorled) leaves with inter-petiolar stipules

• 4-merous in temperate, 5-merous in tropics - tendency to cluster

• only epigynous family in Gentianales

• fruit usually 2-seeded drupe

• pseudanthia

Rubiaceae - coffee

family:

• cyme or dichasium inflorescence

• alternate leaves

• axile placentation

• berry fruited

• 5-merous flowers

• stamens often terminal pored for bee pollination

• often calyx persistent in fruit

Solanaceae - nightshades (potato, tomato, peppers)

family:

• twining herbs or woody with alternate leaves - some parasitic now

• flowers strongly funnel form with plicate corolla tube

• calyx often unfused

Convolvulaceae - morning glory

family:

• cosmopolitan family of opposite-leaved shrubs and trees

• 4-merous flowers

• only 2 stamens

• 1 seeded drupes

• trees: compound leaves- diamond furrowed bark, are unisexual, 1-seeded samara

Oleaceae - olive and ash family

family:

• strongly aromatic

• square stems, opposite leaves

• congested flowers with verticels or terminal heads

• mediterranean climate regions

• bilabiate flowers

• stamens 4 or even 2

• gynobasic, 2 carpels

• fruit- 4 nutlets

Lamiaceae - mints

family:

• square stems

• opposite, serrate leaves

• flowers not lipped

• fruit often 1-2 seeded drupe, not gynobasic

Verbenaceae - vervains

family:

• alternate OR opposite leaved

• round OR squarish stems

• terminal style, many seeds, capsules

• includes normal as well as hemiparasitic species

Scrophilariaceae - figworts

family:

• cosmopolitan, vegetatively diverse, insectivorous herbs of wetlands

• one of the fastest known in the plant kingdom- the trapdoor

Lentibulariaceae - bladderworts

family:

• typically hairy plants

• scirpoid cyme- compound monochasium

• gynobasic style

• fruit typically 4 nutlets or drupe like

Boraginaceae - borage

family:

• opposite, simple leaves

• arcuate venation

• 4-merous, small flowers, separate petals

• 2-carpel, inferior ovary

• fruit is 2-seeded drupe

• some inflorescence surrounded by showy bracts

• head or pseudanthium

Cornaceae - dogwood

what is pollination?

transfer of pollen grains from male anther to female stigma

animal-flowering plant interactions are classic example of co-evolution, what does this mean?

interactions between species as selective forces on each other, resulting in adaptations that increase interdependency

• plants evolve elaborate methods to attract animal pollinators

• animals evolve specialized body parts and behaviors that aid plant pollination

understand that divergence and convergence in pollination syndromes is very common

ok girl

describe some traits that have evolved in flowers to accommodate for different types of pollination

• bisexual flowers to bring male and female parts closer

• closed carpel for protection of ovules and seeds

• fusion of carpels- efficient deposition of pollen and movement of pollen tubes down one or few style lobes

• epigyny- protection of ovules from probing animals

• fusion of floral parts- tubular structures for restricting nectar access

• exotic landing platforms, spurs, nectaries- specialization for specific pollinators

• self incompatibility- chemical on surface of pollen and stigma/style that prevent pollen tube germination on same flower

primitive type of pollination

• numerous parts to flower

• pale or dull in color- strong odor

• flowers have spicy, fruity or rotten smell

flowers pollinated by beetles

primitive type of pollination

• flowers brownish/purple, often mottled, with foetid odor

• 2 specialist species birthwort and arum

• many parasites and saprotrophs

flowers pollinated by flies

most important group of pollinators

• attracted to flower mainly for food

• flowers blue, yellow, white- generally not red

• strong UV light patterns

• nectar guides

• fragrant

• poricidial anthers

• zygomorphic often- landing platforms

flowers pollinated by bees and wasps

• long tube shaped flowers

• flat inflorescences for landing

• usually red and orange

flowers pollinated by butterflies

diurnal or nocturnal

• blooming, white or pale yellow, fragrantm with long tubular structures

• no landing platforms

flowers pollinated by moths

• yellow or red flowers

• little odor or fragrance

• provide fluid nectar in greater quantities

• long, tubular corollas

• pollen is large and sticky

flowers pollinated by birds

• night blooming flowers

• white and aromatic

• robust flowers

• often hanging below crown

flowers pollinated by bats

what is symbiosis?

“close, long-term biological interaction”

definition still highly debated

3 types of symbioses and give and example involving plants

mutualism +/+

parasitism +/-

commensalism +/0

4 major types of mycorrhizal fungi

Arbuscular, Orchid, Ectomycorrhizal fungi, Ericoid fungi

which type of mycorrhizal symbiosis is the most common?

arbuscular

give example of generally non-mycorrhizal plant family

Brassicaceae, Amaranthaceae, Proteaceae, Cyperaceae, some Fabaceae

arbuscular- what resource do the fungi provide for the plant and the plant to the fungi?

fungi provides soil nutrients and water in exchange for carbohydrates and sugars

how far back do mycorrhizal symbioses date?

400 million years

compare and contrast arbuscular mycorrhizal fungi and ectomycorrhizal fungi

they both are a type of root-fungi association but arbuscular penetrates the roots while ectomycrrhizal fungi stays on the outside of the roots

primary structures of ectomycorrhizal fungi

mantles or sheaths around outside of root:

hartig net in between cortical cells

3 primary types of nitrogen fixing bacteria

symbiotic, free-living, associative

explain oxygen paradox w nitrogen fixation

aerobic nitrogen fixation requires oxygen but the N-fixing enzymes must be protected from it.

when are mycorrhizal or rhizobia symbioses non-beneficial?

• when energy costs are too high due to significant carbon allocation

• there are “cheaters” - mycorrhizae that provide little to no nutrients

2 primary functions of haustorium

acts as an anchor and a physiological bridge to the host

• penetrates the vascular system of hosts

• site of nutrient exchange between parasite and host

examples of selection pressures that may give rise to parasitism in plants

• nutrient limitation

• poor soils

• competition for light

3 types of parasitic plants:

hemiparasite- still can photosynthesize, steals water and nutrients

holoparasite- no photosynthesis, steals water, nutrients, AND sugars

mycoheterotrophs- parasitizes mycorrhizal fungi

3 examples of parasitic plants you can find in Cstat

hemp broomrape, indian paintbrush, mistletoe

2 ways dodder bypasses host plant defenses

• alters gene expression

• exchanges RNA with host plant

silences genes responsible for lignin production and programmed cell death

how do parasitic plants promote and maintain biodiversity?

they relax the competition by hindering dominant species

diversity and general characteristics of monocots

very diverse group- many habitats, forms, pollination, etc

• parallel venation

• flower: 3-merous tepals are common

• striking modifications and bracts

monocots- parallel venation and phyllode theory

monocot leaf is derived from an expanded bladeless petiole

theory: original monocots lacked a true leaf, only expanded petiole

monocots- convergence of net venation and fleshy fruits in forest understories

they evolved to have net venation to better capture sunlight in shady understory conditions

family:

• inflorescence with spathe and spadix

• flowers bisexual

Acoraceae - sweet flag

family:

• sister to all Alismatales

• tropical to temperate

• epiphytes herbs, aquatic

• defining characteristic is inflorescence of spathe and spadix

• raphides in vacuoles with mucilage

• Co-oxalate

• flowers uni or perfect

• fruits berries clustered on spadix

Araceae - aroids

family:

• aquatic or wetland

• tubers starchy, often edible

• leaves long petioles, often with sagittate shape leaves

• calyx 3 green sepals, corolla 3 white petals

• Apocarpic in a head or ring

• Achenes

Alismataceae - water plantain

family:

• perianth of 4 clawed segments if present

• gynoecium typically of 4 free, 1-ovuled carpels

• fruit drupe-like

Potamogetonaceae - pondweed

family:

• submersed or floating aquatic plants

• various forms of water pollination present

• pollen water boat floats and attaches to 3 broad stigma of female flower

• male flowers in clusters, female flower single

Hydrocharitaceae - frog bit

Liliods- general characteristics

1. Terrestrial/epiphytes- not aquatic

2. Geophytes

3. Lleaves without petiole

4. Tepals- no bracts

5. Nectaries

6. Capsule/berry fruit

family:

• bulbed or rhizomatous perennials

• leaves without petioles, stemmed or basal

• capsule or berry

• flower often spotted

Liliaceae - lilies

family:

• 3-merous flower, inferior ovary

• liliod monocot, but not in liliales

• one tree-like form

• vegetable and house plants

Asparagaceae - asparagus

family:

• 3-merous flowers

• inferior ovary

• staminal corona

Amaryllidaceae

family:

• leaves basal and equitant (folded and overlapping)

• tepals 6, 3 inner form flags

• 3 outer form the falls with nectar guids

• 3 stamens positioned under the 3 petal-like styles

• gynoecium is inferior and forms 3-parted capsule

Iridaceae - iris

family:

• largest family

• mycotrophic

• all have protocorm

• habitat varies, but more than half are epiphyte

• survive harsh environments bc: CAM photosynthesis, velamen, leaf tubers, mycorrhizal associations

• specialized reproductive biology- labellum (the bucket) for landing platform, pollen masses, dust-like seeds

• capsule fruit

• inferior gynoecium fused at top with stamens to form column

Orchidaceae - orchids

Differences between Liliales and Asparagales

if it has an inferior ovary- always Asparagales

fruit blackened and crusty? Asparagales

Nectaries on base od tepals or stamens? Liliales

Nectaries pm septet of ovary? Asperagales

Introrse dehiscence of anthers? Def Asparagales