One of the head's marginal flowers of a composite plant (such as an aster) that also includes disk flowers. 2: the complete head of a plant that lacks disk flowers (such as chicory). 3: any one of the individual rays arising from a central disk flower.
Ray flowers are usually smaller than disk flowers and often have darker colors. They often resemble miniature versions of the plant they come from. For example, sunflowers have large yellow ray flowers that look like little stars when they open up. Aster plants have smaller white or purple-white flowers with protruding stalks called rays. The name "composite" comes from the fact that these flowers are found in clusters at the end of branches or stems. There are two types of ray flowers: discandrous and cymose. In discandrous rays, each flower is either a ray or a disk. These include most aster species and some chrysanthemum varieties. In cymose rays, each stem or branch carries a single type of ray flower, but many stems grow from the same root system. These include some chrysanthemums and dahlias.
A composite plant can be either herbaceous or woody perennial depending on the amount of storage tissue formed within the root system.
A flower may also be surrounded by leafy features known as bracts. Individual flowers are frequently grouped together to form a bigger bunch or cluster known as an inflorescence. A pedicel is the stalk that supports a single flower, and a peduncle is the stalk that supports an inflorescence or an isolated bloom. The term "flower" can also be applied to small groups of similar plants, such as a family of flowers or a colony of flowers. In this case, the individual members of the group are called petals, stamens, or pistils.
In biology, a pollen grain is the male reproductive cell in plants. Pollen is made up of sperm cells with their nuclei removed, so they are haploid; that is, they carry one set of chromosomes rather than two. The pollen grains are stored inside the anthers, which are structures that produce the pollen. When pollen needs to be released from the anthers, water vapor pressure does it for them. The word "pollen" comes from the Greek pollon, meaning "manure," because of the belief that pollinators were attracted to fresh manure rather than to dead organisms like insects. This theory was proposed by Aristotle and has been widely accepted since then.
Pollen is very important for plant reproduction because it is the mechanism by which pollen gets from one plant to another. Although pollen is usually made of nutrients instead of food, some plants use it as a defense against predators.
(Botany) Any of the little tubular blooms found in the center of the flower head of some composite plants, such as the daisy. Consider Ray Floret. These tiny flowers are about 1/4 inch long and have five petals that fall off early in the season leaving only the stamens inside the tube.
The disk floret is one of the few ways that composites reproduce. The remaining reproductive parts are called anthers and pollen is made up of these little balls of dust that contain sperm cells. When another flower with disk florets receives rain or dew, the water enters through small holes on the side of the flower and wicks up to the surface where it dries into little spheres that fly with the wind to another plant for fertilization.
Sometimes two different types of composites will cross-pollinate, which means their pollen gets blown from one plant to another of a different species. This can happen when two species are close together and pollinated by insects, or if one has Sphaeranthus and the other has Eupatorium because they both have disk florets. When this happens you get hybrids that have traits from each parent.
Flowers... include ovules; the style, a stalked structure atop the ovary that raises the stigma; and the stigma, a sticky knob whose surface receives pollen during pollination. The flower bud begins as a circle of tissue called a meristem that produces two kinds of cells: pollen-making cells and seed-producing cells. The pollen-making cells die after they have made pollen grains, which then fall off the stem into another flower or onto the ground where they can fertilize other flowers on another plant. The seed-producing cells become fruit, which is why plants produce them in abundance.
The flower is the most visible part of the plant and interacts directly with insects that transport pollen from flower to flower on the same plant or between different plants. In order to attract these insects, plants produce certain chemicals that are sensed by the flowers of their neighbors and themselves. The stronger the smell, the more attractive it is to insects who will visit the flowers to feed on their nectar or spread their pollen.
In addition to its odor, each species of flower has a unique color and shape that helps insects recognize it as food. For example, bees visit red roses because they are attracted to the red pigment present in some roses.
The calyx, corolla, androecium, and gynoecium are the four primary sections (or whorls) of a flower (Figure 1). The flower's outermost whorl includes green, leafy features called as sepals. The sepals, known collectively as the calyx, aid in the protection of the unopened bud. They also provide support for the developing fruit when it grows within the flower. Each sepal is made up of three parts: a petal-like projection called a lobe; a rounded tip called an apex; and a basal part called a stalk or pedicel. As with other plants in the plant kingdom, flowers are designed to attract insects that carry pollen from one plant to another. When an insect visits a flower, its stigma contacts the pollen-carrying anthers of the flower's stamens, causing them to release their sperm into the insect. From there, the sperm migrate through the insect's body until they reach eggs carried by the female insect. Upon contact with the sperm, the eggs begin to divide, resulting in a cluster of cells that will eventually become new plants like us.
Within the calyx are smaller, reddish-brown structures called pistils. Like the anthers, the pistils contain pollen that is ready to be transferred to the next generation when fertilization occurs. Pollen is like sperms, so it must be made in large quantities and stored before it is used up.
When a sunflower is in bloom, you'll notice hundreds of tiny blooms developing on a disk, each generating only one seed. Each "disk flower" includes five joined small petals, as well as five stamens united around a pistil with antennae-like stigmas. The term "monoecious" means having one male and one female organ on the same plant. In this case, the sunflower's stigma resembles a female part called an ovary, while the pollen is male.
The word "anemone" comes from the Greek anemi meaning wind, because these flowers usually appear after significant storms. They are also called "wind flowers" or "adder's tongue flowers". Anemones are popular as bedding plants because of their colorful blooms which open mainly due to air movement caused by winds blowing through garden beds. There are several varieties of anemones, most with large flat flowers that seem to float on the surface of the soil. Some have yellow, pink, or white colors and some have darker shades such as maroon or black. The leaves of most anemones fall away when they die back for the winter but those of the tropical false anemone will disappear if the plant is kept in bright full sunlight without any shade or shelter from hot winds or rain.
Anemones are found all over the world in dry climates near water sources such as streams, ponds, and marshes.