- Sunday, November 08, 2015
This article taken from the following link https://ask.extension.org/questions/142181#.Vj_c8eJrwg5
What is the difference between sedum and succulent and cacti? Kalanchoe seems to have many different types. Is Kalanchoe a succulent because it is not winter hardy? Is Dr. John Creech a sedum because it is from the Mountains and is winter hardy?
This question makes an apples-to-oranges comparison, and some basic botany principles are useful in answering it, so bear with me.
Scientific plant identification is called Plant Taxonomy. The entire hierarchy for identifying plants consists of Kingdom, Subkingdom, Superdivision, Division, Class, Subclass, Order, Family, Genus, Species and Cultivar. Fortunately, as gardeners we normally only need to be concerned with the last three classifiers: genus, species and cultivar. Sometimes it’s useful to go up a level and explore Family as well.Genus is a group of closely related species clearly defined from other plants. Species are sub-categories of the genus.
An example of genus and species would be maple trees: Acer is the genus for all maple trees. Under that genus are the species Acer japonicum (Japanese Maple), Acer rubrum (Red Maple), Acer succharinum (Silver Maple) and so on.
A cultivar is a plant or grouping of plants selected for desirable characteristics that can be maintained by propagation. Most cultivars have arisen in cultivation but a few are special selections from the wild. Continuing with the Maple tree example: Acer japonicum ‘otaki’ identifies a specific cultivar of the species Japanese maple.
Most gardening references and plant tags will provide one to three names. If there are three names given with the first capitalized, the second in lower case and the third in single quotations you have the genus, species and cultivar in that order. Example: At your local nursery, a purple coneflower plant would likely be labeled: Echinacea purpurea ‘Magnus' (genus, species, cultivar) If there are only two names given, the first is the genus and the second is the species. If only one name is given and it doesn’t sound like English (usually it’s Latin), it is usually the genus (in this case Echinacea).
If you want to read more about taxonomy, here’s a link to a good description of taxonomy from Colorado State University Extension: http://www.ext.colostate.edu/mg/gardennotes/122.html.
Okay -- So with that out of the way, let’s look the specific plants you’ve asked about:
The term succulent is used to describe plants having some parts (leaves, roots, or stems) that are more than normally thickened and fleshy, usually to retain water in arid climates or soil conditions. But plants are not either succulent or non-succulent. Within the same genus and family there might be plants with thick leaves and normal stems as well as plants with very thickened and fleshy leaves or stems. So deciding what is a succulent is often arbitrary. “Succulent” is a term of description, not a category in formal plant classification.