I much prefer using the Latin names for plants. I find them more descriptive for the plant; for example Clematis alpina is a variety found in alpine regions, Rosa floribunda would be a very free flowering rose, and a Camellia japonica 'alba plena' is a camellia from Japan with white double blooms.
Once broken down, we can work out the nature of so many plants. I've compiled a list of some of the most common terms, but it is by no means exhaustive.
Let's start with simple colours:
Rubra - red
Alba - white
Purpurea - purple
Aurea - gold
Lutea - yellow
Caeruleus/azur - blue
Nigra/ atrum - black
Virens - green
glaucum - blue-green
Versicolour - changing colours
Where plants originate:
canadensis - from Canada
chinensis - from China
japonica - from Japan
elata/elatus - tall
elegans - elegant
flora pleno/plena - double flowers
floribunda - very free flowering
fragrans - fragrant
fragrantissima - very fragrant
fruticans - shrubby
grandiflorus - large flowers
humilis - low growing
longifolia - long leaved
maritima - seaside
montana - of the mountains
odorata - sweet scented
palustris - found in marshes
procumbens - prostrate
reptans - creeping
rivularis - found on river banks
speciosa - showy
spectabilis - spectacular, showy
splendens - splendid
sylvestris - found in woodlands
vulgare/vulgaris - common or having many forms
And finally how the whole genus/species works.
Capital initial for the genus in italic (Clematis). This is the family name of the plant if you like, ie Smith.
Lower case for the species in italic (armandii). This is the given name ie John.
Variety with single quotes 'Apple Blossom' no italic and capital initials.
Clematis armandii 'Apple Blossom' You get the idea.
Of course pretty much all plants have a common name; ie Aquilegias are also known as granny's bonnets here in the UK, but in some other countries these are more commonly known as Columbine. Latin names are the same worldwide - until of course the botanists change them after much research and discussion, for instance a plant recently known as dicentra spectabilis (bleeding heart) is now known as lamprocapnos spectabilis.