Sunflower plants are grown in crop fields and gardens and also grow readily in wildlife settings. These tall, colourful flowers are one of the few species of crop plants that originated in North America. Their highly developed root and flower systems enable sunflowers to adapt to different climate conditions and form symbiotic relationships with other life forms.
Sunflowers grow across a large portion of North America, from central Canada to northern parts of Mexico. According to the University of Wisconsin, the plants also exist in many European countries and are widely cultivated as crops in Russia. In effect, sunflowers can survive in both high- and low-temperature climates ranging from 17.8 to 32.8 degrees Celsius (64 to 91 degrees Fahrenheit). According to Purdue University, the sunflower's ability to adapt within different climates results from the low demand sunflowers make on soil in terms of nutrient requirements. Sunflower seeds also show a high tolerance for cold temperatures during germination periods, which greatly increases their ability to survive in areas that undergo seasonal changes.
Adaptations to Light
Sunflower plants require full sun exposure and will not tolerate a shaded environment. Sunlight adaptations appear within the head of the flower, which rotates or moves with the rising and setting of the sun, according to the University of Wisconsin. Flower petals line the perimeter of the flower head, which can vary in size depending on the type of species. Sunflower heads consist of thousands of tiny flower structures called inflorescences that sit at the centre in a cluster. When fertilised, each flower is capable of producing its own seed. Its leaf arrangement consists of opposite-facing leaves that grow along a tall stem structure, which provides a broad area for sunlight absorption.
Sunflower plants develop symbiotic relationships within the soil environment and with insects, including bees. According to the University of Wisconsin, soil adaptations are demonstrated by the relationships sunflowers have with certain mycorrhizae, or fungus organisms. This adaptation enables sunflowers to ingest ample amounts of organic matter from the soil and makes their root systems more accessible to soil nutrients, such as nitrogen, water and phosphorous. The mycorrhizae benefit by ingesting sugars manufactured by the plant body. Sunflowers' large flower heads and inflorescences contain a nectar that attracts bees, according to Nature North, a botanical reference site. In turn, bees transport the flower's pollen grains from plant to plant, which aids in their fertilisation.