Perennials: Varieties and Cultivars

In nature, sometimes a population of plants within a species differs in some significant way from other members of that species. Maybe the difference is in flower color -- the plants are identical to other members of the same species, except that they have blue flowers instead of white flowers. In these cases, the botanical name of a plant might be followed by a third name, the variety. For example, the common hollyhock has the botanical name Alcea rosea. The black-flowered hollyhock (actually, the blooms are more of a dark, chocolatey maroon) is a variety of hollyhock with the scientific name Alcea rosea var. nigra (sometimes written simply Alcea rosea nigra).

If plant breeders have developed a population of plants that differs from other members of that species, as opposed to it occurring naturally, then the new population is called a cultivar, short for cultivated variety. The cultivar name is customarily written after the genus and species names, and is contained in single quotes. For example, you may have seen a cultivar of lavender called Lady; the proper botanical name is Lavendula angustifolia ‘Lady.’

Plant breeders continue to work to improve plant characteristics of wild species. These improvements might include larger flowers, different flower colors, longer bloom periods, and disease resistance. For example, the cultivated Ancolie hybrid columbines have larger, showier flowers than wild columbines. If you like a more natural look to your garden, however, you may prefer the less showy types. (Note, however, that just because a plant is referred to as "wild" doesn't mean it's easier to grow or requires less care than a cultivated variety.)

This may sound awfully complicated, and in many ways, it is. But a general understanding of how plants are named will go a long way in helping you decipher catalog listings, find the plants you want, and communicate with your fellow gardeners.

That’s enough food for thought for one class! In our next class, the fun begins as we start to develop our garden designs.