Angiosperms (flowering plants)

seed plants with reproductive structures called flowers and fruits

Angiosperms (flowering plants)

what are the two adaptations of angiosperms?

flowers and fruits

under what phylum is angiosperm classifed?

classified in a single phylum, Anthophyta, from the greek anthos for flower

why is angiosperm the most widespread and diverse of all plants

• angiosperms began to replace gymnosperms near the end of the Mesozoic era

• Angiosperms now dominate more terrestrial ecosystems

flower is specialized shoot with up to four types of modified leaves which are?

• sepals

• petals

• stamens

• carpels

enclose the flower

sepals

brightly colored and attract pollinators

petals

produce pollen

stamens

produce ovules

carpels

• filament

• anther (microsporangium)- pollen production

stamen

• stigma

• style

• ovary-egg/ovum production

carpel

typically consists of a mature ovary but can also include other flower parts

fruits

what can fruits do

• protect seeds

• aid in their dispersal

mature fruits can be either?

fleshy or dry

Angiosperms comprise more than 250,000 living species. Previously, angiosperms were divided into two main groups which are?

• Monocots (one cotyledon)

• Dicots (two cotyledons)

• seed leaf

• embryonic leaf, the first to arise from the germinating seed

Cotyledon

DNA studies suggest that monocots form a monophyletic clade, but dicots are?

Polyphyletic

what clade includes most dicots?

The clade eudicot (true dicots) includes most dicots

include the following plants belonging to the oldest lineages

Basal angiosperms

share some traits with basal angiosperms but evolved later

Magnoliids

Dicots are polyphyletic which means this group?

a group whose members do not share a recent common ancestor

What basal angiosperms diverged first from the plant evolutionary tree

the “basal angiosperms” Amborellaceae, Nymphaeaceae and Austrobasileyales diverged first followed by the magnoliid clade before the eudicots and the monocots diverged about 140 million years ago

originated when the angiosperms were still a young clade

Basal angiosperms

• their ancestors become reproductively isolated from the other early flowering plants before distinctive angiosperm traits had originated

• these groups continued to evolve as the other clade evolved

• Amborellaceae, Nymphaeaceae and Autrobaileyales are the extant descendants of that original divergence

characterized by:

• trimerous flowers

• pollen with one pore

• branching-veined leaves

Magnoliids (or Magnoliidae)
- are a group of about 9,000 species of flowering plants

ex: Asimina triloba

what are other specimens of Magnoliids (or Magnoliidae)

• Avocado (Persea americana)

• Black pepper (Piper nigrum)

• Bay laurel (Laurus nobilis)

what are examples of monocots

• Orchid

• Lily

• Pygmy date palm

examples of eudicots

• California poppy

• Pyrenean oak

• Dog rose

• Snow pea

• Zucchini

monocot vs. eudicot: embryos

monocot: one cotyledon

eudicot: two cotyledon

monocot vs. eudicot: leaf venation

monocot: veins usually parallel

eudicot: veins usually netlike

monocot vs. eudicot: stems

monocot: vascular tissue scattered

eudicot: vascular tissue usually arranged in ring

monocot vs. eudicot: roots

monocot: root system usually fibrous (no main root)

eudicot: taproot (main root) usually present

monocot vs. eudicot: pollen

monocot: pollen grain with one opening

eudicot: pollen grain with three openings

monocot vs. eudicot: flowers

monocot: floral organs usually in multiples of three

eudicot: floral organs usually in multiples of four or five