Ch. 23 Flashcards
The angiosperms are named for having ___.
Flowers
Other important derived characters are numerous methods of ________ that result in the plants being pollinated or having their seeds distributed.
Mutually beneficial interactions with animals
The most obvious alteration was the conversion of gymnospermous sporophylls into stamens and carpels, resulting in the ___.
Formation of flowers
In the transition from gymnosperms to angiosperms, fertilization evolved such that the second sperm cell of the pollen tube fuses with the polar nuclei of the megagametophyte, producing the endosperm nucleus. This is called ___.
Double fertilization
In the last century, wind-pollinated trees were grouped together in a “subclass ___” and were considered the most relictual living flowering plants
Hamamelidae
Wind-pollinated trees
Alders, elms, oaks, and plane trees
Recent DNA studies indicate that this syndrome of large, wind-pollinated trees is a derived condition within ____.
Angiosperms
Approximately 100 years ago, C. E. Bessey developed the hypothesis of the ranalean flower, in which..
A magnolia-type flower was thought to be relictual
Most botanists had long ago concludes that angiosperms are ___, and this is confirmed through recent DNA studies
Monophyletic
Currently, many paleobotanists and taxonomists believe that the transition from gymnospermous to angiosperm occurred during the..
Jurassic and lower Cretaceous periods of the Mesozoic era
Soon after their origin, flowering plants began to follow two distinct lines of evolution, and currently, almost all angiosperms are classified as ___ or ___.
Monocots or eudicots
In general, ___ have only one cotyledon on each embryo
Monocots
Monocots usually have ___ veins because the leaves are elongate and strap shaped
Parallel
___ are distributed throughout the stem in monocots
Vascular bundles
No ordinary ___ in monocots
Secondary growth
Monocots have flowers with parts arranged in groups of ___
Three
Eudicots have ___ cotyledons
Two
Eudicots have ___ venation in the leaves
Reticulate
Their vascular bundles forming one ___ in the stem
Ring
___ can be woody, herbaceous, or succulent
Eudicots
Eudicot flowers parts occur in sets of ___ or ___
Four or five
The monocot/eudicot divergence did not occur right away; the early angiosperms diverged into several clades now called the ___
Basal angiosperms
The three groups of extant descendants of these clades, ___, ___, and ___, have not remained static evolutionary and have not preserved all ancestral features intact.
Amborellaceae, Nymphaeaceae, and Austrobaileyales
We assume that features present in basal angiosperms and gymnosperms are relictual features, ___.
Plesiomorphies
In the most relictual members of ___, flowers are large and showy, with three sepals and three petals, but in others, they are highly modified.
Alismatales
Monocots: Liliales
- one of the largest families
- presence of spots or lines on the petals and of rather ordinary nectaries formed at the bases of tepals or stamens
- many ornamental plants, mostly bulbs
- “typical” monocots
- most unusual is Smilacaceae, with single genus Smilax (catbrier)
Monocots: Asparagales
- septa and septal nectaries in the carpels
- ranging from small, delicate bulbs like Hyancinth, chives, and onion (Allium) to vining epiphytes such as many orchids
- agaves and yuccas
- iris
Agaves and yuccas have ___, ___ ___ leaves.
Giant, fibrous perennial
Some members of ___ and ___ have anomalous cambia and grow to be large highly branched trees.
Agavaceae and Ruscaceae
___ has flattened sword shaped leaves
Iris
Monocots: Dioscoreales
- small order has only one family, Dioscoreaceae
- yams
- petiolate, broad leaves with reticulate venation and are easily mistaken for dicots
Yams
Starchy “tubers” produced by several species of Dioscorea and are a major source of carbohydrates for many people of tropical areas
Commelinoid Monocots
Differ from the others in several unusual synapomorphies
Commelinoid monocots: Arecales
- palms, in family Arecaceae
- about 3,500 species
- solitary trunk
- all have scattered vascular bundles
Connelinoid monocots: Poales
- grass family Poaceae and other familiar groups
- about 8000 species and includes most foods
- wind pollinated, so sepals and petals are of little importance and are reduced
- Caryopses
- closely related to grasses are sedges (Cyperaceae) with 4000 species and rushes (Juncaceae)
- cattails (Typhaceae)
- bromeliads (Bromeliaceae)
Caryopses
- usually called “seeds” of corn, wheat, and oats
- actually single-seeded dry fruits
Cyperaceae
- sedges
- 4000 species
Juncaceae
Rushes
Typhaceae
Cattails
Bromeliads
Bromeliaceae
Commelinoid monocots: Zingiberales
- some of the most familiar of all house plants: Maranta, Calathea, canna lilies (Canna), and gingers (Zingiber, Hedychium)
- banana (Musa)
- bird of paradise (Strelitzia)
- large, showy flowers pollinated by insects, birds, or bats
Canna
Canna lilies
Zingibar, Hedychium
Gingers
Musa
Banana
Strelitzia
Bird of paradise
Eudicots
- much larger group than the monocots
- pollen grains have either three germination pores (tricolpate) or have a derived condition from the tricolpate mechanism
Basal eudicots
In older classifications in which all flowering plants were assigned to either monocots or dicots, many families did not seem to fit well in either group
Basal eudicots: Ranunculales
- diverged at early stages in eudicot evolution
- flowers have so little fusion of parts
- buttercups, windflowers, and Clematis
- papaveraceae (poppy flower)
Papaveraceae (poppy flower) is well known for its..
Numerous ornamental species
Basal eudicots: Caryophyllales
- produce betalains
- endosperm develops only a little and then fails to continue growing
- forms perisperm
- phloem plastids contain deposits of fibrous protein located as a ring just interior to the plastic membrane
Betalains
Group of water-soluble pigments
Perisperm
Nucellus cells proliferate and form this nutritive tissue
Basal eudicots: Santalales
- small order of highly modified plants, most of which are parasitic
- mistletoes, Viscum and Phoradendron
Mistletoes
- used as decorations at Christmas
- Viscum and Phoradendron
The remaining eudicots are members of two very large, very diverse clades, the ___ and ___
Rosids and asterids
Rosid clade
- consists of many families that, taken as a whole, are so diverse with respect to vegetative body, flowers, chemistry, and ecology that it is difficult to see they are all related
- vitales, geraniales, fabids, Malvids
Vitales
- Vitaceae
- the grape family
Geraniales
- Geraniaceae
- geranium family
Fabids and Malvids
Eurosids I and eurosids II
5 orders make up 75% of the species in the Rosid clade:
- fabales
- myrtales
- malpighiales
- Rosales
- sapindales
Fabales
Legumes
Myrtales
Eucalyptus and evening primrose
Malpighiales
Poinsettia
Rosales
Roses, elms, marijuana
Sapindales
Maples, horse chestnut, creosote bush
An important character in Rosids is the presence of..
Pinnately compound leaves
Asterid clade
- most derived large clade of eudicots
- sunflower, periwinkle, petunia, and morning glory
- man asters have iridoid compounds
The majority of asterids can be easily distinguished from other angiosperms on the basis of three features:
- sympetalous flowers
- have just a few stamens, not more than the number of petal lobes
- stamens alternate with petals
Sympetalous flowers
Their petals are fused together into a tube
Currently, asterids have the greatest number of species, but they are grouped into two small orders (___, ___) and two groups of orders ___ and ___.
- Cornales, Ericales
- lamiids (euasterids I) and campanulids (euasterids II)
The order Lamiales is quite derived in its floral characters:
Flowers tend to be bilaterally symmetrical and of sizes and shapes that permit only certain insects to enter
Asteraceae
- asters, daisies, and sunflowers
- 1100 genera and 20,000 species distributed worldwide in almost all habitats except dense, dark forests
Asteraceae have a wide range of unique chemical defenses against herbivores:
Sesquiterpene, lactones, monoterpenes, terpenoids, and latex canals that contain polyacetylene resins
The flowering plant clade, the ___, are all classified together in a single division, the ___.
Angiosperms
Magnoliophyta
