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Heliotropism, a form of tropism, is the diurnal or seasonal motion of plant parts (flowers or leaves) in response to the direction of the Sun. The habit of some plants to move in the direction of the Sun, a form of tropism, was already known by the Ancient Greeks. They named one of those plants after that property Heliotropium, meaning "sun turn".
The Sun is the star at the center of the Solar System.It is a massive, nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy from its surface mainly as visible light and infrared radiation with 10% at ultraviolet energies.
The androecium is one of the fertile cycles of flowers. The parts that make up the androecium are called stamens whose function is the generation of male gametophytes or pollen grains. The stamens are highly modified leaves formed by a foot that is inserted into the receptacle of the flower, called filament, and a distal portion called anther ...
[1] [6] The flower stem is known as a pedicel, and those flowers with such a stem are called pedicellate, while those without are called sessile. [7] In the angiosperms, the flowers are arranged on a flower stem as an inflorescence. Just beneath (subtended) the flower there may be a modified, and usually reduced, leaf, called a bract.
A plant that loses all of its leaves only briefly before growing new ones, so that it is leafless for only a short time, e.g. approximately two weeks. bristle A straight, stiff hair (smooth or with minute teeth); the upper part of an awn (when the latter is bent and has a lower, stouter, and usually twisted part, called the column). brochidodromous
The core of the Sun is considered to extend from the center to about 0.2 of the solar radius (139,000 km; 86,000 mi). [1] It is the hottest part of the Sun and of the Solar System . It has a density of 150,000 kg/m 3 (150 g/cm 3 ) at the center, and a temperature of 15 million Kelvin (15 million degrees Celsius; 27 million degrees Fahrenheit).
What appear to be "petals" of an individual flower, are actually each individual complete ray flowers, and at the center is a dense pack of individual tiny disc flowers. Because the collection has the overall appearance of a single flower, the collection of flowers in the head of this sunflower is called a pseudanthium or a composite.
The flowers would have tended to grow in a spiral pattern, to be bisexual (in plants, this means both male and female parts on the same flower), and to be dominated by the ovary (female part). As flowers grew more advanced, some variations developed parts fused together, with a much more specific number and design, and with either specific ...