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  2. Heliotropism - Wikipedia

    en.wikipedia.org/wiki/Heliotropism

    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".

  3. Alternaria helianthi - Wikipedia

    en.wikipedia.org/wiki/Alternaria_helianthi

    There are eight different species that cause yield loss of sunflowers; however, Alternaria helianthi is the primary causal agent and most widespread. [5] The main hosts are sunflowers (Helianthus annuus); however, it has been proven that safflower (Carthamus tinctorius), noogoora burr (Xanthium pungens), cocklebur (Xanthium strumarium), and Bathurst burr (Xanthium spinosum) can serve as ...

  4. Common sunflower - Wikipedia

    en.wikipedia.org/wiki/Common_sunflower

    Sunflowers do not have a pulvinus below their inflorescence. A pulvinus is a flexible segment in the leaf stalks (petiole) of some plant species and functions as a 'joint'. It effectuates leaf motion due to reversible changes in turgor pressure which occurs without growth. The sensitive plant's closing leaves are a good example of reversible ...

  5. How to Grow the Biggest and Brightest Sunflowers This Summer

    www.aol.com/grow-biggest-brightest-sunflowers...

    Alas, most sunflowers are annual flowers, meaning they do not come back each year like perennial flowers. But, there's a few pieces of good news. But, there's a few pieces of good news.

  6. Cold hardening - Wikipedia

    en.wikipedia.org/wiki/Cold_hardening

    Cold hardening is a process in which a plant undergoes physiological changes to avoid, or mitigate cellular injuries caused by sub-zero temperatures. [1] Non-acclimatized individuals can survive −5 °C, while an acclimatized individual in the same species can survive −30 °C.

  7. Helianthus paradoxus - Wikipedia

    en.wikipedia.org/wiki/Helianthus_paradoxus

    Pecos sunflower is an annual, herbaceous plant. It grows 1–3 meters (3.3–9.8 ft) tall and is branched at the top. The leaves are opposite on the lower part of the stem but alternate at the top, lance-shaped with three prominent veins, and up to 17.5 centimeters (6.9 in) long by 8.5 cm (3.3 in) wide.

  8. Helianthus - Wikipedia

    en.wikipedia.org/wiki/Helianthus

    The disk of a sunflower is made up of many little flowers. The ray flowers here are dried In North Carolina A sunflower seed growing. Sunflowers are usually tall annual or perennial plants that in some species can grow to a height of 300 centimetres (120 inches) or more.

  9. Plant perception (physiology) - Wikipedia

    en.wikipedia.org/wiki/Plant_perception_(physiology)

    Plant perception is the ability of plants to sense and respond to the environment by adjusting their morphology and physiology. [1] Botanical research has revealed that plants are capable of reacting to a broad range of stimuli, including chemicals, gravity, light, moisture, infections, temperature, oxygen and carbon dioxide concentrations, parasite infestation, disease, physical disruption ...