An enlarged, inflated, flower-bearing spadix protrudes from the vase-shaped spathe. The bizarre Malaysian Amorphophallus paeoniifolius. Seymour in Scientific American, March 1997. Heat production in aroids is discussed in a fascinating article by R.S. Like heat-producing tissue in mammals, the cells in these flowers rapidly oxidize lipids and carbohydrates, thus releasing heat. In some species in which the upper part of the spadix is sterile (flowerless), the heat mechanism appears to be in the cells of this sterile tissue. The heat mechanism may involve male flowers packed around the spadix.
This may stimulate the activity of pollinator insect visitors and help to vaporize the stench of the flowers. In fact, the temperature of the spadix can be up to 30 degrees Celsius above a cool air temperature of 10 degrees Celsius. The spadix of some aroids produces a remarkable amount of heat during cold weather.
The spadix of some arums emits a putrid odor that attracts carrion flies for pollination. The spadix emerges from a vase-shaped or funnel-like modified leaf or spathe which is often brightly colored.
Individual flowers are reduced to a single stamen or pistil (gynoecium). Male (staminate) flowers consist of numerous stamens packed together, while female (pistillate) flowers consist of numerous individual pistils. The upper region of the spadix is usually devoid of flowers. The small unisexual flowers are packed together along the lower region of an erect, phallus-like central spike, typically with male flowers above the female. It consists of a thickened, fleshy axis (spike) bearing clusters of sessile, apetalous, unisexual flowers. The spadix is the characteristic inflorescence of the remarkable arum family (Araceae). Spadix: Inflorescence Of The Arum Family (Araceae) Seedless, parthenocarpic fruits may be produced without pollination by male trees.įlowers & Multiple Fruits Of The Mulberry Familyĥ. In the aggregate fruit of a blackberry, all the drupelets of the cluster (syncarp) come from a single flower. Each ovary (carpel) becomes a drupelet and the ripened cluster of drupelets (syncarp) is called a multiple fruit. Each carpel or pistil (also referred as a gynoecium) consists of a forked stigma, a short style and a spherical ovary. Male flowers have four stamens while female flowers consist of single pistil tightly enveloped by four inconspicuous sepals. Mulberry flowers are produced in a catkin, with male and female catkins on different trees. Since mulberries are wind-pollinated, male trees produce copious pollen which can raise havoc with hay-fever sufferers.įemale catkin from a variety of black mulberry ( Morus nigra). Male trees are known as "fruitless mulberry" because they do not produce messy fruits that stain clothing and walkways. At the base of each filament is a fleshy green sepal. Right: An individual male flower containing four stamens, each with an anther and a filament. Left: Male (staminate) catkin from the white mulberry ( Morus alba), a fruitless variety commonly planted as a shade tree in southern California. Catkin: Inflorescence With Unisexual Flowers Note: The term scorpioid cyme is more correctly referred to as helicoid cyme.Ĥ.
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