Garden Detective: botanical name system

Bleeding hearts will be blooming soon, but you'd better not call them Dicentra spectabilis anymore, unless you add "formerly known as" before that moniker. That's because the plant has been officially renamed Lamprocapnos spectabilis.

The little heart-shaped blooms that seemingly "bleed" white are springtime garden favorites and are unusual in that their foliage dies back to the ground shortly after flowering, opening up the space for summer annuals or perennials. Plus, they thrive in the shade beautifully alongside hostas, ferns, primulas and aquilegias.

But why the name change? The genus Dicentra has been split, with several of its species moved into the newly created Lamprocapnos genus. Other genera have been shaken up, as well, including the transfer of Antirrhinum, Digitalis, Hebe and Penstemon into the plantain family, Plantaginaceae.

Why do we even need botanical names anyway when we have plenty of common names for plants and they're easier to pronounce? Because we have so many common names to call plants by.

In different regions of our country and in different countries of the world, different common names are applied to the same plants. Depending on whom you talk to, Hypericum calycinum can be called Aaron's beard or St. John's wort. Eupatorium coelestium might be referred to as hardy ageratum, mistflower or wild ageratum. To complicate matters, the plant called ironweed in Georgia is completely different from the plant called ironweed in the Midwest (the former is Sidai; the latter, Veronica, which around here is called speedwell.)

Carolus Linnaeus saw this could be a problem in the 1700s. His claim to fame was breaking down genera into species and devising the modern system for naming plants and animals. He also was infamous for having a dirty mind.

Linnaeus was the Swedish botanist, zoologist and physician who wrote "Systema Naturae" and "Fundamenta Botanica," which set the rules for the classification and naming of plants in botanical Latin.

Here's the International Code of Botanical Nomenclature system he established and how it's used. You'll find it handy when shopping from your gardening catalogs.

The genus is the first word of a name. It's always capitalized and in italics. It's a noun, naming the plant based on its structure. Often, this is the same as the common name.

Species is the second word in the botanical name. It, too, is always in italics, but lowercase. The species is considered the adjective, describing the plant. This is where Linnaeus earned his off-color reputation. Think about plants labeled vulgaris. Pretty racy stuff in those days. Or Avocado, named for the Aztec word for testicle, pretty racy stuff even today. Vainilla, the botanical name for vanilla, which is taken from an orchid pod, means "little vagina." Do orchids remind you of anything?

(Sometimes, there's a subspecies. In those cases that name would come next.)

Third is the plant's variety name, which describes the naturally occurring differences among species. It's always lowercase and never in italics. If the variety is named after a proper noun, like a place or a person, then it's in single quotes. It's preceded by "var." in the name.

A cultivar name may sometimes be in third place instead of a variety.A cultivar is bred and cultivated by a horticulturist in a lab. Cultivars are written in single quotes, always capitalized, never in italics.

Or the third name may be a hybrid: a cross between two different plants, usually a lab or greenhouse creation. It is indicated by "x" before the hybrid name.

In the plant kingdom, the biggest group, the first subcategory is family, which you usually don't see. When you do see a name ending in aceae, (pronounced Ay'-see-ee), that's the family.

A popular dwarf French marigold, for instance, is the 'Janie Flame' cultivar of the patula species in the Tagetes genus and Asteraceae family. On a plant tag or in a catalog, it would be listed as Tagetes patula 'Janie Flame.'

All these names are derived from habit, shape, character, kind, part, season, region, color, size, degree or form. When Linnaeus noticed similarities between certain body parts and flowers he made those body parts part of the botanical name -- and that's what got him into trouble.

There's actually an International Botanical Congress that has been meeting every six years since 1900 to discuss and decide such issues based on new information gleaned from the latest genetic research and scientific findings. The next congress will be held July 24-30 in Melbourne, Australia, so stay tuned.

To keep on top of the most up-to-date botanical names, check the Royal Horticultural Society's free online Garden Plant Finder at apps.rhs.org. uk/rhsplantfinder. Nurseries selling plants are listed for the Brits, but the proper nomenclature is universal.