Plant Tax Exam 2 Review

gymnosperm vs angiosperm ovule

Angiosperm basically takes the gymnosperm ovule and adds a bunch of stuff surrounding it

9 evolutionary novelties

1. Closed carpel

2. 2nd layer of integument

3. Megagametophyte= embryo sac

4. Microgametophytes from microsporangia in anthers

5. Pollen transfer >/= wind (early beetle pollination)

6. No pollination droplet, sticky surface of stigma

7. Pollen tube is longer, grows through style to ovary and ovule

8. Double fertilization produces zygote (2n) and endosperm (3n)

9. Fruit production and other carpel modifications for dispersal

What makes Ceratophyllum so strangely different?

• no endosperm, no apertures on pollen, no filaments, 1 carpel, 1 integument

• Submerged aquatic plant

• Extremely reduced flowers

• Filiform (thread-like) leaves

• No obvious roots

• Very simple morphology compared to other angiosperms

What was the flower of Archaefructus like? (plus floral formula)

• Apocarpous carpels

• Stamens below carpels

• No calyx or corolla

• No perianth

• Laminar stamens

• Possibly aquatic herbaceous plant

• *, 0, 0, ∞, ∞, follicles

What monocot traits connect them to Magnoliids and dicots?

• Spiral floral arrangement in some early monocots

• Tepals rather than sepals + petals

• 3-part flower structure

• Scattered vascular bundles

Traits supporting monocot monophyly

• One cotyledon

• Parallel venation

• Fibrous root system

• Scattered vascular bundles

• Floral parts in 3s

Monocot family with the most species (and why)

Orchidaceae

• Extreme pollination specialization

• Tiny wind-dispersed seeds

• Mycorrhizal germination

• Ability to colonize many habitats

Iris flower modifications

Adaptations:

• Petaloid style branches

• Stigma located underneath the style arm

• Anthers also under the style arm

Pollination process:

1. Bee lands on the sepal (“fall”)

2. Crawls into tunnel between sepal and style arm

3. Contacts stigma first, then pollen

Iris vs Acorus

Iris

• Equitant leaves

• Showy flowers

• Specialized pollination

• Inferior ovary

Acorus

• Simple flowers

• Spadix inflorescence

• 6 tepals

• Early monocot lineage

Aloe vs Agave comparison

Similarities

• Succulent leaves

• Rosette growth

• Dry habitat adaptation

Differences

Agave

• New World

• Often monocarpic

• Fibers used for rope

• Fruit = capsule

Aloe

• Old World (Africa)

• Leaves mucilaginous (medicinal)

• Often bird pollinated

Arecaceae traits

• Spathe present

• Branched spadix

• Fruits usually drupes

• Huge tropical diversity (~2600 species)

Wind-pollinated monocot traits

• Reduced flowers

• No bright petals

• Lots of pollen

• Feathery stigmas

• Exposed anthers

• Inflorescences elevated in wind

Evolutionarily advanced Zingiberales traits

• Large herbs

• Bilateral flowers

• Inferior ovaries

• Petaloid staminodes

• Pseudostems

• Arillate seeds

• Perisperm

Bromeliads (Bromeliaceae)

• Many epiphytes

• Leaf rosettes that collect water

• Showy bracts

• CAM photosynthesis

• Important habitat for insects and amphibians

Ranunculales synapomorphies

• Numerous stamens

• Numerous carpels

• Often apocarpous

• Many have secondary metabolites

• Often early spring ephemerals

Families in the Proteales (and why they are grouped)

Proteaceae , Nelumbonaceae, and Platanaceae

• Single ovule per carpel

Magnolia cone vs Banksia cone

Magnolia

• Aggregate of follicles

• Each follicle from a separate carpel

• Carpels arranged on elongated receptacle

Banksia

• Woody cone-like infructescence

• Many fruits embedded in a woody axis

Both of these cones evolved independently

What fruit types are these: Apple, Yucca, Coconut, Milkweed, Tangerine

Apple- pome, Yucca- septicidal capsule, coconut- drupe, milkweed- follicule, tangerine- hesperidium