The echinacea flower, a commonly used medicinal supplement, in full bloom.
Echinacea in full bloom

Also called purple coneflower, or simply coneflower, echinacea has long been used for medicinal purposes in North America by the Native Americans. In total, there are nine species of echinacea, and, historically, echinacea was a very popular remedy for a host of different kinds of afflictions, including malaria and scarlet fever. Although its popularity has declined with the introduction of antibiotics, there are still very real benefits that people take advantage of and continue to research. There are studies that show that echinacea can reduce the chances of contracting colds, and when taken during sickness, reduce the length of the sickness (both the cold and the flu). The best time to take echinacea is when symptoms first develop. This will shorten the sickness more than waiting until the disease has taken full effect. Echinacea is sold as a supplement, however, it also brews a tea (which was also been used in clinical trials) that produces the same effects. 

As for the plant itself, it is a perennial, that has tall stems, reaching 4.5 ft at its tallest, adorned with single pink or purple flowers and a central cone where seeds are stored in a comb. An important note is that the upper part of the plant is what contains the compounds that will help treat cold and slow healing wounds. The root of the plant can be used to treat cold and flu-like symptoms in a tincture (1.5 ml in water up to three times a day). It is also important that echinacea might interfere with medication that treats autoimmune diseases, so it’s always good to do research to make sure it won’t interfere with any prescriptions!

If you want to plant your own echinacea, make sure it gets a good amount of sun. Partial shade is okay, and the soil should have a balanced pH and equal parts of sand, clay, and silt. Consider planting more pollinator attractors with it such as butterfly weed and bee balm. As for vegetables, plant with eggplant, broccoli, brussell sprouts, cabbage, cauliflower, chillis, peppers, and tomatoes.

References:

https://www.mountsinai.org/health-library/herb/echinacea

https://nathaliestrassburg.com/2021/02/25/echinacea-growing-guide/