The gloriosa daisy belongs to the genus Rudbeckia of the Asteraceae family. Other species within the Rudbeckia genus are the black-eyed susan and the brown-eyed susan, both of which resemble the gloriosa daisy. The gloriosa daisy is botanically named Rudbeckia hirta or sometimes Rudbeckia gloriosa. Generally, people know it best for its daisy-like composite flower heads.
A composite flower head usually consists of two types of tiny florets: ray florets and disk florets. The ray flowers are the showy outer ones that are strap-shaped with tubular bases. The center of the flower heads is composed of the disk florets. These tiny flowers are tubular and mature into the seedpods. The disk florets of the gloriosa daisies are borne on a raised, conical center.
Gloriosa daisy plants generally have thick, erect stems that frequently branch. The flowers are borne singly at the ends of the stems. The stems are often long and usually make excellent cut flowers.
The basal, or ground level, leaves are usually ovate to diamond-shaped and strongly veined. They may be up to 4 inches (about 10 cm) long. The stem leaves tend to be narrower than the basal leaves. Often they are ovate to lance-shaped. All of the leaves are mid green and solidly colored.
The color of the flower heads depends on the cultivar. R. hirta has pale yellow to golden yellow ray florets with brown to brownish purple disk florets. One of its cultivars, Irish eyes, is sometimes called green eyes because it has green disk florets surrounded by bright yellow ray florets. Another cultivar, rustic dwarfs, has yellow-orange ray florets heavily brushed with red-orange or brownish red. Becky mixed has ray florets in varying shades of lemon yellow, deeper golden-yellow, and dark red.
Gloriosa daisies are perennial plants. With proper care and in the appropriate climate, they will return in the spring from the same roots. The plants usually bloom in their second year. In frost-heavy regions, gardeners grow it as an annual.
They are native to meadows and woodland edges in parts of North America. Gloriosa daisy plants are usually hardy in zones three to seven according to the USDA hardiness chart. This means that the plant may survive lows of about -30°F (about -35°C), but generally does not tolerate extreme heat.
Generally, gardeners propagate gloriosa daisy plants by sowing seeds in early spring or by dividing the established clumps of plants in the spring or autumn. Many new cultivars are often available at nurseries, both local and by mail order. When buying the daisies, gardeners need to be careful not to choose plants of the genus Gloriosa, which belongs to the lily family. This genus has only one species that is a semi-tropical or tropical climbing plant from Africa and India.
Although some sources describe the gloriosa daisy as a medicinal plant, no scientific literature supports these claims. Some people report that the Native Americans made an infusion from the roots that they used to wash sores and treat snakebites. Other literature relates that they made drinks for treating colds. It is possible that they used it as a cure for worms in children, in addition to using the root extracts for earaches.