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Ch. 24: Seed Plants II: Angiosperms - Coggle Diagram
Ch. 24: Seed Plants II: Angiosperms
Concepts
magnoliophyta
-The flowering plant clean-the angiosperms-contains the greatest number of living species. These are all classified together in a single division
In most angiosperm carpels, The edge of sporophyll primordia Crowd against each other and grow shut, sometimes closing so completely that no sign of a seam remains. This is called a
closed carpel
.
The evolutionarily changes involved in conversion of a gymnospermous line into an angiosperm line did not occur instantaneously, nor did they occur in all species.
Double Fertilization was probably the first transformation because it is universally present.
The ability to produce bisexual flowers must also has been one of the first transformations because of flowering plant clades have megasporophylls located above microsporophylls on a single axis
Vessel elements probably evolved next because only one or two basil species like them.
Sieve tubes May have originated next; several species still have sieve cells in their phloem.
All gymnosperms and seed ferns are or were woody plants, and so are most of the basal angiosperms and eudicots.
The annual habit- ability to germinate, grow, reproduce, and then die all within a single year- is a uniquely angiosperm feature.
Changing concepts about early angiosperms
hypothesis of the
ranalean flower
In which a magnolia type flower was thought to be relictual. Such a flower is generalized; that is, it has all parts and these are arranged spirally
Many paleobotanists and taxonomist believe that the transition from gymnosperm to angiosperm occurred during the Jurassic and lower Cretaceous period of the Mesozoic era.
Classification of flowering plants
Flowering plants begin to follow two distinct lines of evolution, and currently almost all angiosperms are classified as monocots or eudicots.
Early angiosperms diverged into several clades now called the basal angiosperms. These are not a newly discovered species; they have just been classified as monocots or eudicots prior
The 3 groups of extant descendants of these clades- amborellaceae, Nymphaeaceae, and Austrobaileyales- Have not remained static evolutionarily and have not preserved all ancestral features in tact.
Nymphaeaceae Are the water lilies. They are small, soft bodied herbs with vascular bundles scattered like those in monocots And they completely lack any wood. In most their stems must be submerged underwater and exposure to ordinary conditions on land would kill them. Their large colorful flowers are pollinated by animals.
Uniaperturate
- pollen grains have only a single germination pore.
Basal Angiosperms
Contain the living descendants of several groups that originated when angiosperms were still a young clade. Their ancestors became reproductively isolated from the other early flowering plants before distinctive angiosperm traits had originated.
Monocots
Currently, monocots Are widely believed to have arisen from early angiosperms approximately 80 to 100,000,000 years ago. All monocots lack secondary growth and Wood, their ancestors were probably herbs with either no vascular cambium or little cambium activity.
The perianth usually consists of three outer and three inner members; they often look so similar that rather than using the terms sepals and petals the perianth members are just called
tepals
Some plants grow completely submerged in water therefore no transpiration. This mutation results in a loss of stomata and it's not selectively diss advantageous
Asparagales
septa
- When carpels few side-by-side starting at their bases. They do not fuse all the way up to the style however and the open areas secrete nectar; these are
septal nectaries
commelinoid monocots
-Differ from the others in several unusual synapomorphies: They have unique types of epicuticular wax. Their walls have unusual types of hemicelluloses and ultraviolet fluorescent compounds.
Eudicots
Betalains
- water-soluble pigments
perisperm
- A nutritious tissue formed by the nucleus cells that surround the developing embryo
rosid clade
Consists of many families that, taken as a whole, are so diverse with respect to vegetative body, flowers, chemistry, and ecology that is difficult to say they are all related. However some sharing of characteristics with others to indicate a relationship.
The two large clades of rosids are the
fabids
also called the
eurosids I
and the
malvids
(
eurosidsII
).
