PLANT OF THE WEEK

Dr. T. Ombrello - UCC Biology Department

GERBERA

Common names:  

Transvaal Daisy, Barberton Daisy, African Daisy, Veldt Daisy, and Gerbera  

Scientific name:        Gerbera Jamesonii

Explanation of scientific name:       

Gerbera      - named in honor of T. Gerber, a German naturalist.

Jamesonii  -  named for Dr. L.S. Jameson, a British colonial statesman in South Africa who was one of the discoverers of this species.

The Transvaal Daisy is one of approximately 70 species of Gerbera.  All are perennials from South Africa, but only a few in addition to Gerbera Jamesonii are grown as ornamental flowering plants.  In nature, this species produces many leaves, up to 10 inches in length, from a compact stem at the soil surface. The leaves are woolly on their undersides and radiate out from a central growing point in a rosette fashion.  In May, the plants produce flower stalks up to 1½ feet tall, topped with single daisy-like orange flower heads up to 4 inches across.  Individual blossoms are durable and may last up to 4 weeks on the plants.

When the Transvaal Daisy was first discovered and brought into cultivation over 100 years ago, its primary use was for cut flowers because they were so long lasting.  Plant breeders have been working with the species for many decades now, and have produced new cultivars that are more compact and come in a variety of flower colors.  In addition to orange, they come in red, yellow, pink, white, salmon, and violet.

Today Transvaal Daisies are still grown for cut flowers (outdoors in California and Florida, in greenhouses in other parts of the United States) but are becoming increasingly popular as potted plants and as bedding plants outdoors.  Grown from seed they will reach flowering size in 6 to 9 months, but they can also be propagated by division.  Offsets growing from the base of a mature plant can be separated from the parent and grown as individuals.

As members of the Sunflower family of plants (now Asteraceae, formerly Compositae), the Transvaal Daisies count as close relatives such diverse plants as asters, chrysanthemums, dahlias, dandelions, lettuce, marigolds, sunflowers, and zinnias.  The family includes over 20,000 species, making it one of the largest families in the plant kingdom, representing about one tenth of the species of flowering plants.  They are all grouped in the same family because of their unique flowers.

The actual flowers of Transvaal Daisies, as well as those of all members of the Sunflower family, are very small and closely grouped into a compact “head”.  The head, often consisting of hundreds of flowers, is commonly mistaken for a single blossom.  There are usually two types of flowers making up the head.  The disk flowers, with petals fused into an inconspicuous tube, make up the main body of the head.  The ray flowers, each with a single strap-shaped petal on one side, are found along the outer edge of the head.  The single petals of the ray flowers are large and showy, which serve to attract pollinators to the flower head.  But, these flowers are frequently sterile and produce no seeds, instead depending on the less showy but fertile disk flowers to produce offspring.  In some species only disk flowers or only ray flowers are present on the head.

The flowering head strategy has numerous advantages for the members of the Sunflower family.  The head is usually quite conspicuous to pollinators in comparison to individual flowers.  Pollen is readily exposed to all comers, and at least several flowers are pollinated by a single insect during one visit.  Insects need no special body or head parts to get at the nectar in the flowers, so the species are not normally dependent on one particular kind of pollinator.  This head type, along with other characteristics, makes this family one of the most highly evolved among flowering plants.