Seed Plants II: Angiosperms

Changing Concepts About Early Angiosperms

Classification of Flowering Plants

Basal Angiosperm

Monocots

Commelinoid Monocots

Eudicots

Rosid Clade

Asterid Clade

Basal Eudicots

100 years ago the Ranalean flower hypothesis was developed by C. E. Bessey

when a flower is generalized is has all parts

most botanists concluded that angiosperms are monophyletic

this includes double fertilization, flowers, and development plasticity

they believe they transition from gymnosperm to angiosperm occurred during the Jurassic period and Lower Cretaceous Periods

they can see this kind of things through fossils

the oldest wood was found in Japan 125million years old

Magnoliophyta is a large group

they are described as either monocots or eudicots; some are tricky to identify

monocots usually have parallel veins,vascular bundles, and do not have ordinary secondary growth and wood

their flowers are in multiples of threes

eudicots are more diverse

their flowers occur in sets of 5 or more

the early angiosperms diverge into several clades now called basal angiosperm

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this group contains the living descendants of several groups the originated while the angiosperm were still young

the extant descendants of this group include Amborellales(Small Trees), Nymphaeales(water lilies), and Austrobaileyales

the water lilies live as rhizomatous aquatic herbs in temperate and tropical climates around the world.

these small trees are found in the forests of New Caledonia; dioecious with small flowers

all three have undergone massive change since their clades originated

Asparagales

Liliales

Dioscoreales

Alismatales

Poales

Zingiberales

Arecales

Caryophyllales

Santalales

very large and very diverse clade

contains many aquatic herbs and aquarium plants

found is swamps and marshes

they have no transpiration; air chambers make the plant buoyant

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"petaloid" monocot; 11 families and 1,300 species

the petals often have spots or lines on them

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only one family

their carpels fuse side by side being called septa; the open area secretes nectar

the flowers are large and colorful

important food crop called yams

Yams are starchy "tubers"; they have broad leaves with reticulate venation

These are different from other monocots because they have epicuticular wax, their waslls have unusual types of hemicellulose, and untra-violet compounds

the palms; 3500 species with their solitary trunk

scattered vascular bundles; leaves are near the apex

the leaves are simple that can be tor by wind into different patterns

grass family; 8000 species; they include wheat, barley, rye, corn, rice, and sugar cane

they are abundant in flat, open dry regions in the central area of all continents

grasses are wind pollinated; sepals and petals are not important

cattails grow in ponds and marshy areas;they produce fruits and flowers

closely related are the sedges and rushes; they live in marches with tiny flowers and small dry fruits

familiar house plants such as Maranta and canna lilies

they often have large showy flowers; adjacent sepals

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distinctive feature includes three germination pores(tricolpate): their flower parts are arranged in whorls

this group includes cacti, iceplant, and Russian thistles

they produce water soluble pigments called betalains; the endosperm never fully grows so instead they produce perisperm

sieve tube plastids

most a parasitic and live with their host plant

the common mistletoe is apart of this group; have chlorophyll and are photosynthetic

they all share enough in common to be classified together

the two large clades are the Fabids and the Malvids; over 100 families; 14 large orders with 50,000 species

important characteristic is the pinnately compound leaves

the Fabales, Myrtales, Malpighiales,rosales, and sapindales contain 75% of the species

produces roses and apples

contains plants such as sunflowers, periwinkle, and petunias

they have sympetalous flowers, they always have just a few stamens, and the stamens alternate with petals

it does not contain betalains alkoloids, or ellagic

60,000 species

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