You would think, because daisy flowers all have an identical ground design of central disc surrounded by botanical, they’d have an identical uniform way of seed dispersal. But this is not the situation. Daisies belong to many different genera from the composite family, growing in diverse habitats and climates, with seed dispersal mechanisms which work for that specific atmosphere. Daisy seeds ride the wind on parachutes or wings, get transported around by birds, cling to animal fur and are spread by human actions.
Each daisy head bears many seeds, since the eye or central disc is made up of many small flowers attached to a frequent base, known as the receptacle, in the base of the flower head. Each little flower or floret contains five fused petals that form a tube. After pollination, the blossom ovule, which is buried at the receptacle, forms a seed. In many daisies, stiff hair-like constructions, known as pappus, attach to the top of the seed. These bristles are what is left of the sepals of each blossom. In ordinary non-composite flowers, sepals are the green structures which enclose the flower bud and stay beneath the blossom as it participates.
For a good mental picture of a seed having a parachute, remember what a dandelion seedhead resembles. Blow on the puffy white pappus bristles and they sail away, each carrying a small pointed brownish seed at the bottom. Santa Barbara daisy (Erigeron karvinskianus), by way of example, has pappus-dispersed seeds after booming. This perennial daisy flowers spring, summer and fall with profuse little white flowers that age to pink. It’s hardy to U.S. Department of Agriculture plant hardiness zones 8 or 7 through 11.
Perennial coreopsis (Coreopsis lanceolata), also called lance-leaved coreopsis, is a good illustration of a daisy which has flattened extensions on all sides of the seed, forming thin wings that catch the wind. Native to America and growing in USDA zones 4 through 9, flowers have yellow ray flowers tinged red in the base and gold disc flowers, blooming all summer, attracting bees and butterflies.
Some daisy seeds have been retained in the seedhead and have to be automatically eliminated. These are made for bird crop. Think about sunflowers (Helianthus annuus) which have a nutrient-rich large naked seed that needs to be pried out of the sunflower’s receptacle. Eager birds like finches and cardinals cluster around seedheads, knocking out seeds which fall to the ground to germinate as they harvest others. Sunflowers grow as an annual plant everywhere. Apart from garden daisies that rely on feeding birds for dispersal contain blanket blossoms (Gaillardia pulchella), black-eyed Susan (Rudbeckia spp.) And purple coneflower (Echinacea purpurea), all perennial native flowers which grow in USDA plant hardiness zones 4 through 9. Blanket purple and purple coneflower seedheads also include stiff bristles or chaff that encompass the seeds and help hold them in position, so if your aim is to save seeds from such plants, then use gloves when shooting the seedheads apart.
Other Dispersal Mechanisms
Tickseed (Bidens spp. And cultivars) are free-flowering white or yellow low-growing perennial daisies native to North America. They climb in USDA zones 8 through 11, but grow as annuals in colder areas. Seeds are flat with two prominent hook-shaped awns at the top, which fasten onto clothing or beast. Some daisies don’t have any clear dispersal mechanisms in their seeds, and don’t disperse away from the parent plant unless aided by human action. A good example is the oxeye daisy (Leucanthemum vulgare), an annual which went from being a European wildflower to your noxious North American grass. Imported from the 1800s as a garden plant, oxeye daisy naturalized to each state and many Canadian provinces. It distributes in feed mixes, contaminated vehicles and grazing animals.