FLOWERS, POLLEN, OVULE Flashcards
reproductive organ of a plant
organ for sexual reproduction that involves the union of gametes
flower
modified shoot with a compressed axis, bearing a series of floral leaves that have been variously modified
flower
The point of attachment for the various modifications
receptacle
are modified leaves which encase the rest of the developing flower. They may be either green and leaflike, or composed of petal-like tissue.
Sepals
the expanded end of a flower stalk on which the flower parts are borne
receptacle
Sepals collective term
calyx
are modified leaves usually functioning as visually conspicuous “signposts” which serve to attract specific pollinators.
Petals
Petals collective term
corolla
Calyx and corolla taken as one is called
perianth
collective term is androecium
Stamens and pollen
composed of sac-like anthers and filaments that are stalks that support the anthers
Stamens
form an erect tube
filaments
filaments form an erect tube called
staminal tube
consist of 2 sacs, each of which contains two microsporangia
Anthers
occurs in numerous microspore mother cells in the microsporangia, each microspore mother cell producing four microspores
Meiosis
becomes a pollen grain or microgametophyte.
microspore
Flowers can be borne singly or in aggregations called inflorescence
true
Flowers in which the four basic parts are present are called
complete
Flowers in which the four basic parts at least one part is absent are called
incomplete
four basic parts of a flower
sepals, petals, stamens, and carpels
collectively called gynoecium
Pistil and carpel
three regions of the pistil (from the base up)
ovary, style and stigma
where the ovules are found
ovary
stalked structure atop the ovary that elevates into a sticky knob
style
sticky knob
stigma
In the gumamela, the style is found inside the staminal tube while the five stigma project from this tube.
true
The ovary is often divided into chambers called
locules
inside the locules are the
ovules
Meiosis occurs in a megaspore mother cell in each ovule, producing four megaspore. Three of these disintegrate, leaving a functional megaspore,
true
a functional megaspore, which divides mitotically to produce the
embryo sac or megagametophyte
having the corolla composed of united petals
gamopetalous
one of the outer parts of a flower (collectively the perianth), The term is used when these parts cannot easily be classified as either sepals or petals.
tepal
having many distinct or separate petals
polypetalous
bundle of leaves or flowers growing crowded together
fascicle
Flowers can vary from containing both male and female parts
perfect
Flowers containing just one sex
imperfect
Flowers having no sexual parts
sterile
Female and male flowers are located on separate plants
dioecious
Female and male flowers are located on the same plants
monoecious
petals of the flower can either be free from each other
polypetalous
petals of the flower can either be united forming a cup or tube with separate terminal lobes.
gamopetalous
symmetry is based on a wheel plan
flower is divisible on more than one axis into two equal halves that are mirror images of each other
radial symmetry
actinomorphic symmetry
distinctly divisible into right and left sides; that is, it is divisible into mirror images on only one axis.
bilateral symmetry
irregular or zygomorphic symmetry
four types of irregular flowers
bilabiate, caesalpinaceous, orchidaceous and papilionaceous.
A flower with superior ovary is such that the stamens, petals and sepals arise from a level below the base of the ovary
hypogynous flower
that the flower has superior ovary but the bases of the stamens, petals and sepals develop as a floral cup around the pistil. Hypanthium
Perigynous flower
the stalk of an individual flower within an inflorescence.
pedicel
stalk of an inflorescence (containing one to many flowers)
peduncle
part of the flower that turns into the pericarp
ovary wall
part of the flower that turns into the seed
ovule
part of the flower that turns into the seed coat
integument
The main axis (also referred to as major stem) above the peduncle bearing the flowers or secondary branches
rachis
a flower cluster with the separate flowers attached by short equal stalks at equal distances along a central stem. The flowers at the base of the central stem develop first.
raceme
is a raceme, but the flowers develop directly from the stem and are not borne on pedicels
spike
- a compound raceme; an indeterminate inflorescence in which the flowers are borne on branches of the main axis or on further branches of these
panicle
one in which the flower stalks arise at different levels on the main axis and reach about the same height and in which the outer flowers open first
corymb
consists of a number of short flower stalks (called pedicels) that spread from a common point, somewhat like umbrella ribs.
umbel
a short dense spike in which the flowers are borne directly on a broad, flat peduncle, giving the inflorescence the appearance of a single flower
head
instead of individual flowers radiating out from a single point, there are instead inflorescence branches. At the ends of each branch are secondary umbels.
Compound umbel
a flat-topped inflorescence in which the central flowers open first, followed by the peripheral flowers
compound cyme
The main axis terminates in flower and it produces one lateral branch from the base, which also terminates in a flower. Each lateral and subsequent branch also produces one lateral branch with a terminal flower.
cyme
typically surrounded by a leaf-like curved bract known as a spathe
spadix
a form of pollination whereby pollen is distributed by wind
Anemophily
a form of pollination whereby pollen is distributed by water
hydrophily
a form of pollination whereby pollen is distributed by insects
entomophily
a form of pollination whereby pollen is distributed by bats
chiropterophily
a form of pollination whereby pollen is distributed by birds
ornithophily
a type of cymose inflorescence
like a hollow-sphere (syconium) with a cavity inside, and it is formed by the fusion of the rachis of the three cymes in the vicinity of each other. These spherical receptacles are like a closed fleshy vessel having a tiny opening at the apex; it opens to the exterior with this opening.
Hypanthodium
the basic unit of a grass flower, consisting of two glumes or outer bracts at the base and one or more florets above.
spikelet
specialised pseudanthia (“false flowers”) forming the inflorescence of plants\
the brackets fuse to form a cup-shaped structure
cyathium
a cuplike or tubular enlargement of the receptacle of a flower, loosely surrounding the gynoecium or united with it. In epigynous and perigynous, not hypogynous
hypanthium
