MAY 2023 | VOL. 23
THE OUTSIDER Illinois Extension Horticulture serving Henry, Mercer, Rock Island, and Stark
SUNFLOWERS: BELOVED BLOOMS, SECRET TALENTS Sunflowers are a long-time garden favorite. The bright sunny blooms and extremely tall plants are among the most recognizable plants in the garden. But there is more to the sunflower than is evident in their beauty.
HELIANTHUS SPP. Sunflowers are part of the Asteraceae family; a family that consists of over 32,000 known species of flowering plants. Other members of the Asteracea family include garden favorites such as coneflowers (Echicaea spp.), cosmos (Cosmos spp.), dahlia (Dahlia spp.), lettuce (Lactuca sativa), marigold (Tagetes spp.), and zinnia (Zinnia spp). In a family so large, there are members considered by some as not so favorable including dandelion (Taraxacum sp.), ragweed (Ambrosia sp.), and thistle (Carduus, Cirsium, and others). The Greek word for star is aster and is the base word for the family name. Star shapes and groups of five are demonstrated in many of the family’s plants. Many blossoms exhibit five petals, five stamens, and/or five pistols. An alternative name for the family is the Compositae and refers to the composition of the floral head. Composite blooms are unique inflorescence that are made up of many smaller flowers that appear to be a single floral head. In a sunflower, the ‘petals’ or ‘sunrays’ are individual flowers known as ray flowers or ray florets. The ‘sun disk’ is made of hundreds of small flowers called disc flowers or disc florets. College of Agricultural, Consumer and Environmental Sciences
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