Scott Aker, horticulturist at the Cheyenne Botanic Garden and former garden communicator with the U.S. National Arboretum in Washington, D.C., confessed to misspelling spiracea (omitting the first a) on garden maps and emails for five years before discovering his error. Over the course of years Aker encountered a number of cases where horticultural and gardening terms tend to be misused or misunderstood. Based on his experience, here are some of the topics that seem to cause the most confusion.
One of the most common errors is confusion of the terms "variety" and "cultivar". which should not be used interchangeably. A cultivar--the word is a contraction of the words "cultivated" and "variety"--designates plants that differ from naturally occurring plant populations in some way. To qualify as a cultivar, human hands must have created or selected that plant.
|Creeping Charlie weed|
|Creeping Charlie houseplant|
There also seems to be a movement toward capitalization of all words in common names, likely because they stand out more in marketing materials. In general usage the only part of a common name that should be capitalized is a person or place name, like "black-eyed Susans- or "Boston ivy".
Plural forms are sometimes confusing. If you are using Latin names, the plural is always the same form as the singular. Example, I planted a single Rhododendron in my garden. Tomorrow I will plant five more Rhododendron. The plural in English usage is boxwood, not boxwoods, in the same way that a single doe is a deer and 20 like her are collectively also called deer.
To add more confusion, in some cases more than one spelling is correct: gladioluses and gladioli are both allowed, but gladiola is not the correct term for a single gladiolus.
One of the pet peeves of Aker is seeing the word horticulturist rendered as horticulturalist. The former is the preferred dictionary choice and is shorter and simpler. However you do see the latter version quite often, perhaps people think that extra syllable makes it sound more impressive.