Basic Plant Taxonomy

Personal notes for RHS Level 2 Certificate in the Principles of Plant Growth and Development

Unit 1: Plant Science 1: Scientific and common plant names: AO1.

In horticulture, plant taxonomy is the science of classifying plants based on their characteristics and evolutionary relationships. It involves categorizing plants into different groups based on their physical and genetic traits.

A family is a group of plants that share similar characteristics and are related to each other through a common ancestor. Members of a family share similar flower structures, fruit types, and other physical features.

A genus is a group of plants that share similar characteristics and are closely related to each other. Members of a genus share similar flower structures, fruit types, and other physical features. Examples of genera include Rosa (roses), Ficus (figs), and Acer (maples).

A species is a group of plants that share similar characteristics and can interbreed to produce fertile offspring. Members of a species share similar flower structures, fruit types, and other physical features. Examples of species include Rosa canina (dog rose), Ficus carica (common fig), and Acer saccharum (sugar maple).

A cultivar (cultivated variety) is a variation within a plant species that has been selectively bred by humans for specific desirable traits, such as color, size, or disease resistance. Cultivars are usually propagated asexually (e.g., by cuttings or grafting) to maintain their desirable traits. Examples of cultivars include Rosa ‘Peace’ (a hybrid tea rose), Ficus ‘Brown Turkey’ (a fig cultivar), and Acer ‘October Glory’ (a red maple cultivar).

A variety is a naturally occurring variation within a species that has been selected for specific desirable traits. Varieties can be propagated sexually (e.g., by seed) or asexually (e.g., by cuttings or grafting) to maintain their desirable traits. Examples of varieties include Rosa canina var. glauca (a dog rose variety with blue-green leaves), Ficus carica ‘Black Mission’ (a fig variety with dark purple fruit), and Acer saccharum var. nigrum (a sugar maple variety with dark bark).

A species is a plant that is the result of crossbreeding two different species or cultivars. Hybrids can be created for specific desirable traits, such as disease resistance, hardiness, or color. Examples of hybrids include *Rosa ‘Double Delight’ (a hybrid tea rose), Ficus ‘Janice Seedless’ (a fig hybrid), and Acer x freemanii ‘Autumn Blaze’ (a red maple hybrid)

* seen in photograph (via Wikipedia).