plants exam 2 301 eccb

What are the relationships and defining features of monocots, dicots, and eudicots? Do they form clades?

Monocots have one cotyledon in their seeds while dicots have two.

Eudicots have tricolpate (pollen grains with three pores) while monocots and dicots are monocolpate

What is monocolpate and tricolpate pollen?

Monocolpate is pollen grains with single pores and tricolpate are pollen grains with three pores

What is ANITA?

A grade (not a clade)

Earliest diverging angiosperms

Amborellales, Nymphaeales, Iliaceae, Trimeniaceae, Austrobaileyaceae

6 traits that are common to all of the ANITA and Magnoliid families

1. Many parts at each whorl

2. Separate, unsealed carpels

3. Follicle fruits (mostly)

4. Laminar stamens

5. Tracheids, no vessel elements

6. Pollen grains single pored, apertured, furrowed; not triaperturate, tricolpate

Where are most ANITA species located, and what are the implications of this for our understanding of the early biogeography of angiosperms?

Most are located in tropical regions especially in the pacific. (New caledonia) This has the implications that these angiosperms originated in the Australia area/southern hemisphere

Why are these lineages dicots but not eudicots?

The pollen grains are single pored, apertured, furrowed, tricolpate in in eudicots only

How are these lineages related to the eudicots?

ANITA are sister group to all other angiosperms like the eudicots

Are all aquatic plants closely related to each other, or do distantly related species show ecological convergence?

There is ecological convergence in the aquatic plants (Nelumbonaceae and Nymphaeaceae) (lotus lily and water lily)

Amborellaceae

Amborellales order

Sister to all other angio

Amborella trichopoda endemic to New Caledonia

dioe everg shrub no vessels

P 5-8, A inf/0, G 0/5-6

perianth of tepals, laminar stamen, apocarp, fruits 1 seeded drupelike

Nymphaeaceae

Nymphaeales order

water lilies, WW, air cav in tissie, lack vessels,

many parts at whorl, laminar stamen, superior syncarpic pistil

Ca 4-inf, CO inf A inf G_inf

Nymphaeceae are sister to

all angiosperms not including Amborella

Magnoliaceae

Magnoliales order

trop/warm tree/shrub large leaves, large solitary flower

P inf, A inf G_inf

fruits of one flower = aggregate of follicles

Magnoliids are sister to

all angiosperms except ANITAs

Aristolochiaceae

Piperales order

wild ginger

climbing/rhizomatous herb, cordate leaves

CA 3, CO 0, A-inf, ^G 4-6 (inferior ovary)

calyx colloid, petals absent, inferior, syncarpic

Ranunculaceae

Ranunculales order

eudicots, buttercup

herbs, woody/herb climber/shrub, poisonous

leaves alt, sheath, basal/cauline, divided, palm lobed, no stipules, apocarp

CA 3+, CO (0)5+ A inf G_3+

Papaveraceae

Ranunculales order

drugs

herb alt latex caducous sepal

CA 2 CO 4-12 A ing G_2-inf

Capsule = dehiscing syncarp fruit

Nelumbonaceae

Proteales

lotus lily

used to be closely related to nymphaeaceae but no more

peltate leaves, solitary flower

spiralled perianth - tepals, filamentous stamens

P inf A inf G_inf

separate superior one seeded carpels in cavities of obcon receptacle

What is nitrogen fixation and why is it important?

Plants cant use nitrogen in its gaseous form so it is fixed as usable nitrate or ammonia and is absorbed by the plants to be fed or add back in soil - important nutrient for plants and soil

Fixed with bacteria or lightning

What is the general floral formula shared by many (not all) rosids that can be used to distinguish from the ANITA/Magnoliids?

CA5 CO5 A10 G (variable)

Violaceae

Malpighiales

basal/cauline, cordate/palmate,divided, stipules well dev

inscect pollinated, zygomorphic, 5mer, petal spurred, 3 fused carp

cleistogamous flowers - capsules self pollination

CA 5 COZ 5 A 5 G_3

Euphorbiaceae

Malpighiales

latex, alt simple palm comp, unisex flowers, spurges, cyathium modified inflorescence

CA 5, CO 0, A inf/0, G/g 0/3

Fabaceae

Fabales order

monocarpic - single superior carpel

legumes

alternate compound leaves

Rosaceae

Rosales

CA 5 Co 5 A inf G vary

hypanthium in all, bracts, commercial fruits, stipules well, gyn vary

Moraceae

Rosales

fig

sister to nettle, latex, palmipinnate veined

CA 4 Co 0 A 4 G_2

uni flowers no petals single seed ovary

many flowers coalesce to form fleshy multiple fruit

synconium key innovation for fig wasp pollination

Fagaceae

Fagales

wind pollinated, uni, flowers in catkins, inferior G 2-3, nut

What is a cyathium, as seen in Euphorbia and Chamaesyce?

Modified inflorescence which a cup structure appears as a single flower but is a cluster of reduced unisexual flowers. It is composed of glands, bracts, male flowers, and 1 female flower

Fabaceaea key terms, including names of unique petals, diadelphous vs monadelphous stamen, etc.

Banner petal = topmost petal sits in front of the 2 lateral / WING petals

diadelphous = 9+1 nine stamens are fused together into a sheath, while one stamen remains separate and free

monadelphous =ten filaments are fused together into a single tube surrounding the style

Rosaceae (vegetative features, floral structure, hypanthium, variable gynoecium structure and fruit types)

alt, always stipules, separate petals, a prominent cup-shaped hypanthium, numerous stamens, and highly variable gynoecium (superior to inferior) and fruit types, including pomes, drupes, and achenes

Geraniaceae

Geraniales

fruit schizocarp

CA 5 Co 5 A 10 G_5

5 mer sup pistil single ovule

Onagraceae

Myrtales

CA 4 Co 4 A 4,8 G^4

4 mer epig well dev hypa, inferior ova

Lythraceae

Myrtales

Ca 4-6 CO 4-6 A 8-12 G_4

4,5,6 mer stamens double sepals

hypath well dev, perigynous (sup pistil)

Anacardiaceae

Sapindales

shrubs compound alternate rashes 5 mer

CA 5 Co 5 A 5,10 G_2-3

disk,drupes

Sapindaceae

Spaindales

maples

trop wood, opposite compouind, drupe/samara

CA 4-5 CO 0/4-5 A 8,10 G_2

unisex flowers by abortion 45mer, nectariferous disk

sup pistil 2 carp 2 exstyl

Malvaceae

Malvales

mallows broadly defined

palm veined, valvate sepal (no overlap), stellate hairs, stamens mondelphous

CA 5 CO 5 A inf G_5-inf

Brassicaceae

Brassicales

mustard

oil herbs - brocbruscaulikale

arabidopsis - genetic/genome model plant species

CA 4 CO 4 A 4+2 G_2

cross flower 4, 6 stam+2 out, 2 fused carpels in gynoe

fruit is a capsule that peels off and expose septum

What is tristyly heterostyly and why it is important?

Tristly heterostyly is a plant reproductive strategy where the plant population has 3 flower morphs where the sets of anthers and styles have different positions. This promotes outcropping(maximum cross pollination) and prevents self fertilization/inbreeding

It’s 2026 and we’re still arguing about what is a species. Why?

There is no one way to define a species. A species concept can not be universally applied to every species.

If species are a problem, why do we still use them?

Species can be used for identification, communication, and scientific reasons.

What are the implications for how we define species?

How we define a species affects the level of care or interest the species will receive. Splitting/lumping can affect whether a species is considered vulnerable or not.

“Species are groups actually or potentially interbreeding natural populations that are reproductively isolated from other such groups.”

-reproduction has to be possible

Biological Species Concept

Biological Species Concept pros/cons

pro - easy to distinguish/test

cons - does not consider hybridization and asexual reproduction

“ A community, or number of related communities, whose distinctive morphological characters are, in the opinion of a competent systematist, sufficiently definite to entitle it, or them, to a specific name.”

-distinct characters

Morphological Species Concept

Morphological Species Concept pros/cons

pros - intuitive/easy to identify

cons - subjective, does not consider relation or convergence

“A number of related populations the members of which compete more with their own kind than with members of other species.” A lineage (or a closely related set of lineages) which occupies an adaptive zone minimally different from that of any other lineage in its range and which evolves separately from all lineages outside its range.”

-niche/function

Ecological Species Concept

Ecological Species Concept pros/cons

pros - based on functions

cons - hard to measure and hard to find a point where you stop splitting

“A diagnosable cluster of individuals within which there is a parental pattern of ancestry and descent, beyond which there is not, and which exhibits a pattern of phylogenetic ancestry and descent of units of like kind.”

-the smallest definable group of organisms that are descended from a common ancestor and share a unique trait

Phylogenetic Species Concept

Phylogenetic Species Concept pros/cons

pros - based on ancestry

cons - does not consider reproduction + convergence

“A lineage of interbreeding organisms, reproductively isolated from other lineages, that has a beginning, an end, and a distinct evolutionary trajectory”

-Emphasis is on adaptive traits and lineages maintaining distinct identity from each other

-beginning/end

Evolutionary Species Concept

Evolutionary Species Concept pros/cons

pros - can prove by testing genes

cons - genetics show different phylogenetic patterns, few lineages maintain distinct identities for long

What are the criteria of a good species concept?

1. They should be universal (i.e., apply to plants and animals)

2. They should be testable (e.g., does a group of organisms comprise a species?)

3. Special case species definitions should fit within its broader logical framework

4. It must deal with species having ‘spatial, temporal, genetic, epigenetic, ecological, physiological, phenetic, and behavior’ traits.

5. It must specify how species can or can not be formed.

Be able to clearly define and defend your preferred species concept.

My preferred species concept Phylogenetic Species Concept because it defines a species by distinct clusters that share a common ancestor. This applies to plants and animals and deals with species traits.

General characteristics of Asterales

- No iridoids
- Latex common
- Inferior gynoecium
- Pollen presentation

- composite

- capitulum

What is secondary pollen presentation?

- anthers fuse forming a tube for pollen release, where it is pushed out by a style that acts as a plunger
- the stigma makes contact with its own pollen (self fertilize) if necessary

How does secondary pollen presentation promote outcrossing? How does it ensure reproductive success?

It promotes outcrossing by limiting self fertilization which limits inbreeding and increases fitness

It ensures reproductive success by maximizing pollen transfer efficiency

What are the important features thought to be involved in the massive radiation in Asteraceae?

- special inflorescence "head" (capitulum)

- pollination syndromes and presentation

- diverse secondary chemistry (latex, alkaloids, polyacetylenes, sequiterpene lactones- poisonous to sheep)

- whole genome duplication (unique to Asteraceae family)

Know the terms associated with the specialized Asteraceae inflorescence and florets

- capitulum - specialized inflorescence
- radiate head: disk floret in the center, ray florets along the edge
- discoid head: only disk or tubular florets comprise the entire head
- ligulate head: only ligulate florets comprise the entire head

Know the three floret most common floret types (ray, disk, ligule)

- ray floret: usually 3 long fused petals +2 obsolete petals
- disk floret: actinomorphic
- ligule floret: 5 fused petals but split open

Know the three most common arrangements of these florets

- radiate inflorescence
- discoid inflorescence
- ligulate inflorescence

Asteraceae key traits

composite flower head with capitulum, involucre

Be able to discuss the different dimensions of ‘biodiversity’

What are the different ways that we value biodiversity? What are the relative strengths and

weaknesses of these views? Should we value biodiversity for its own sake? Why or why not?

species - species richness the number of species in a defined place - con species are made up and only one aspect of diversity

phylogenetic - diversity of lineages - con many different metrics

functional - determined by functional traits of species in an ecosystem/way of measuring the diversity of how things are con - many traits to measure who cares

We discussed several species that are endangered in Texas. What do they have in common?

What is the primary that causes plant species to be rare in Texas?

- over collection
- habitat loss
- development
- competition with non native species/risk of hybridization

Simple fruits

fruits formed from a single pistil

Floral Formula: CA CO A G

- CAlyx (sepals)

- COrolla (petals)

- Androecium (stamens, male)

* if line under above 3 = hypanthium

- Gynoecium (carpels, female)

* if # is circled = carpels fused

* if line above G = ovary inferior

* if line under G = ovary superior

Aggregate fruits

fruits formed by the development of several pistils from the same flower

Multiple fruits

fruits formed by the development of pistils from multiple flowers, usually joined together by accessory parts (e.g., pineapple, mulberry)

Dry fruits

(simple fruit)

fruit coat dries at maturity

Fleshy fruit

(simple fruit)

fruit is soft and fleshy as it matures

Dehiscent fruits

(dry, simple)

at maturity, these open by natural means to shed seeds

Indehiscent fruits

(dry, simple)

these do not open at maturity to shed seeds

Legumes fruit

(simple, dry, dehiscent)

developed from 1 carpel, splits along two lines of suture (e.g., peas, beans)

Follicle fruit

(simple, dry, dehiscent)

developed from 1 carpel, splits along only one line of suture (e.g., Columbine, Larkspur)

Capsule fruit

(simple, dry, dehiscent)

developed from several carpels, with various numbers of suture types

Achene fruit

(simple, dry, indehiscent)

one-seeded, with it attached to fruit wall at single point (e.g., sunflower seeds)

Nut fruit

(simple, dry, indehiscent)

one-seeded, but the fruit wall is thickened and hardened (e.g., chestnut, oak, hickory)

Samara fruit

(simple, dry, indehiscent)

one or two seeded, part of the fruit wall forms a wing (e.g., elm, maple, ash)

Grain fruit

(simple, dry, indehiscent)

one-seeded, fruit wall and seed coat are fused (e.g., corn, wheat)

Schizocarp fruit

(simple, dry, indehiscent)

formed from several carpels, each with a single seed, which separate from each other at maturity (e.g., carrots, dill)

Drupe fruit

(simple, fleshy)

one-seeded fruit from a superior ovary (e.g., cherry, mango, avocado)

- endocarp: becomes hard and stony

- exocarp: becomes relatively thin

- mesocarp: is fleshy

Berry fruit

(simple, fleshy)

ovary wall becomes enlarged and juicy (e.g., banana, grape, tomato, bell pepper, blueberry)

2 types: hesperidium & pepo

Berry: Hesperidium

berry where the exocarp forms a leathery rind, interior is separated into septa (e.g., lemons, limes, oranges)

Berry: Pepo

berry where the exocarp forms a hard rind, but the interior is not separated into septa (e.g., cucumber, watermelon, squash, gourds)

Pome fruit

(simple, fleshy)

an 'accessory fruit' (other floral structures form part of the fruit) comprised of multiple carpels in the same flower (e.g., apple)

Blackberry fruit

aggregate of drupes

Strawberry fruit

aggregate of achenes

Seed parts

1. endosperm

2. embryo

3. seed coat

Pericarp parts

4. endocarp

5. mesocarp

6. exocarp