Coneflowers (Echinacea) are perennial garden plants native to central and eastern North America. Known for their daisy-like appearance and prominent central cones, they are often added to perennial borders. This guide details the physical characteristics of the coneflower seed, its position within the flower head, and the process of collecting it.
Physical Characteristics of the Coneflower Seed
The coneflower seed is an achene, a small, dry, one-seeded fruit that does not open to release the seed. These seeds typically measure between 3 to 5 millimeters in length. They possess a distinctive elongated, somewhat conical or pyramidal shape, often described as four-sided or wedge-shaped.
The color ranges from dark brown to nearly black, helping them stand out against lighter chaff. The surface texture is hard and firm, lacking the fuzzy tufts found on some other seeds. A subtle ridge or point may be visible along the body of the seed.
Appearance varies slightly among Echinacea species; for example, Echinacea purpurea seeds are more robust than the slender seeds of Echinacea angustifolia. The seed is the dark, dense material that remains once the outer husk, or chaff, is removed.
The Seed Head Structure
Coneflower seeds are tightly embedded within the central structure of the dried flower, known as the receptacle or cone. The genus name Echinacea is derived from the Greek word “echino,” meaning hedgehog, referencing the cone’s spiky appearance. This structure previously held the purple or pink ray petals during the bloom season.
As the flower matures in late summer or fall, the petals drop off, leaving a prominent, hardened, and prickly center. This central cone transforms into a dry, brown, or black structure that is firm and spiky to the touch. The seeds are nestled deep between the pointed bracts, or chaff, covering the cone’s surface.
The seeds must be physically extracted from this hard, protective cone by breaking the structure apart. This embedded location protects the seeds from early dispersal and provides food for birds during colder months. The entire cone must be fully dried and brittle before the seeds are mature enough for collection.
Collecting and Storing Coneflower Seeds
The optimal time to collect coneflower seeds is in late fall, once the seed head is completely dry and the seeds have fully matured. Harvesting should be done on a dry day to ensure the seed heads are free of moisture, preventing mold during storage. The mature seed heads can be snipped off the plant using pruners, leaving a short length of stem attached.
To extract the seeds, the dried cones can be rubbed, shaken vigorously over a container, or carefully broken apart. Wearing gloves is recommended to protect hands from the spiky cones. The extracted material is a mix of dark seeds and lighter chaff, which should be separated by gentle sieving or blowing away the debris.
For long-term storage, the cleaned seeds must be kept in a cool, dark, and dry environment to maintain viability. A breathable container, such as a paper envelope or small glass jar, is preferred. They should be clearly labeled with the collection date. When stored properly, coneflower seeds can remain viable for up to three years.