Common sunflower

**Botanical Characteristics**:
– Genus name derived from Greek words for sun and flower
– Species name means annual in Latin
– Erect stem reaching up to 3 meters in height
– Largest sunflower on record grew to 9.17m
– Broad, rough, coarsely toothed leaves
– Leaves near the bottom are heart-shaped
– Plant flowers in summer with large flower heads
– Flower head consists of numerous small florets
– Outer flowers called ray flowers
– Center flowers mature into sunflower seeds
– Prairie sunflower similar in appearance to common sunflower
– Diploid genome with 17 base chromosomes
– Estimated genome size of 2,871–3,189 million base pairs
– Some sources suggest a size slightly larger than the human genome

**Cultivation and Production**:
– First domesticated in the Americas
– Sunflower seeds introduced to Europe in the 16th century
– Russia and Ukraine produce over half of global seed production
– Commercially, sunflower seeds are planted 45cm apart and 2.5cm deep
– Proper cultivation practices are essential for maximizing sunflower yields
– Sunflowers require specific spacing and planting depth for optimal growth
– Cultivation techniques vary based on location and climate conditions
– In 2020, global sunflower seed production reached 50 million tonnes
– Russia and Ukraine combined accounted for 53% of the total production
– Sunflower seeds are a significant agricultural commodity worldwide
– Production levels are influenced by factors like climate and agricultural practices
– Sunflower production contributes to the economy of many countries

**Historical Significance**:
– Sunflowers were cultivated by Native Americans in prehistoric North America
– Evidence suggests sunflowers were first domesticated in Mexico around 2600BCE
– Sunflowers were used symbolically by indigenous American peoples
– The sunflower became an economically important crop in eastern North America
– The cultivation of sunflowers spread from America to Europe and Russia over time

**Ecological Impact and Uses**:
– Sunflowers face threats from diseases like Fusarium, downy mildew, and broomrape
– Fusarium, a filamentous fungus, causes significant damage to sunflower crops
– Downy mildew affects sunflowers due to shallow planting in moist soil
– Broomrape, a parasite, attacks sunflower roots leading to extensive crop damage
– Sunflowers can extract pollutants like lead, cadmium, zinc, cesium, strontium, and uranium from soil
– They can neutralize radionuclides like caesium-137 and strontium-90 from contaminated areas
– Used in response to the Chernobyl and Fukushima Daiichi nuclear disasters
– Annual species are planted for their allelopathic properties
– The Zuni people use sunflower root for snakebite treatment

**Cultural and Symbolic Significance**:
– Sunflowers were traditionally used by Native Americans for various purposes
– The sunflower is the national flower of Ukraine
– Ukrainians historically used sunflower as a cooking oil source during Lent
– Sunflowers were planted to clean nuclear waste in Chernobyl
– Sunflowers have become a symbol of resistance and hope globally
– Sunflowers symbolize spiritualism and hidden disabilities
– Hold meanings of positivity and strength
– Represent hidden disabilities through sunflower lanyards
– Connected to the language of flowers
– Used in spiritual practices and mediumship