Way back in February, I wrote What’s in a Name? Part the First, with every intention of following it up regularly to explore the meanings behind many botanical names. It’s taken me much longer than I’d expected to get going, but now that the growing season is slowing down, I’m excited to finally have some time to get back to this. First up, names that relate to colors: in this case, white to black and everything in between.

There’s certainly no lack of references to white in botanical names. Most often, it’s some indication of the flower color, but it can relate to other structures too, or even to the whole plant.

• Alba (or albus or album) is an easy one to remember: Aquilegia flabellata var. pumila f. alba (white-flowered dwarf fan columbine, shown above) and Campanula latifolia var. alba (white-flowered bats-in-the-belfry, shown at right) are just two examples.
• The prefix “alb-“ is another simple clue that something white is probably evident, as in albiflorus (white-flowered), albicaulis (white-stemmed), or albifructa (white-fruited).
• Albescens indicates that some part of the plant turns white, as with the bracts of Pycnanthemum albescens (white-leaved mountain mint).
• Candida or candidus or candidum – as in Zephyranthes candida (white-flowered rain lily) – indicates bright white. The closely related candidissima suggests a very bright white, which makes sense in the case of the pure white Deutzia scabra ‘Candidissima’ (rough deutzia) but not so much with Arisaema candidissima, which is as much pink as it is white.
• A few other terms that relate to snowy white features include chionantha (think of the elegant Eomecon chionantha [snow poppy] or Chionanthus virginicus [white fringe tree]) and nivea/niveus/niveum (referring to the flowers in the case of Tanacetum niveum [silver tansy]).
• There are terms for less-than-pure whites too, including eburnea/eburneus/eburneum for ivory white (as in Carex eburnea [ivory sedge]) and margaritacea (-us, -um) for pearly white (as in Anaphalis margaritacea [pearly everlasting]).
• Lactose (literally, milk sugar) is a term that’s in common usage, so it’s easy to remember that lactea/lacteus/lacteum and the prefix “lacti-” all refer to milky white. Some examples include Callicarpa americana var. lactea (the white-berried form of American beautyberry) and Artemisia lactiflora (the white-flowered white mugwort).
• For creamy white, there’s ochroleuca (-us, -um) – as in Scabiosa ochroleuca.
• For generally pale features, there’s pallida (-us, -um), as in Echinacea pallida, a purple coneflower that has white pollen, along with the prefixes “pallid-” (think of Fritillaria pallidiflora [the pale-flowered fritillary]) and “leuc-” or “leuco-” (as in Leucanthemum and Leucanthemella [shown at right], with white daisies, or Leucophyllum, with silvery white foliage).

 As the color drifts toward the grayish to silvery range, there’s another group of terms you may recognize.

• When the appearance is gray to grayish white (usually due to a covering of hairs or fuzz), there’s cana/canus/canum, as in Agastache canum (hummingbird mint).
• The closely related canescens refers to being or becoming gray to grayish white; think of Amorpha canescens (leadplant), which tends to be fuzzed all over, or Rhododendron canescens (Piedmont azalea), hairy mostly on the undersides of the leaves.
• Incana/incanus/incanum indicates an appearance that’s even more noticeably gray to grayish white; think of the bluebeard species Caryopteris incana or Marrubium incanum (silver horehound).
• When a grayish or whitish (or blue-gray) cast comes from a waxy coating, you’ll often see glauca (or glaucus or glaucum), as in Picea glauca (white spruce), Rosa glauca (grayleaf rose, shown at right), and Echeveria glauca (blue echeveria), to name just a few examples.
• Once you know what glauca means, it’s easy to guess that glaucescens relates to becoming (or being) whitish, grayish, or bluish due to a waxy coating, as for Ferrocactus glaucescens (a barrel cactus).
• For ash-gray, there’s cinerea, as in Eucalyptus cinerea (silver dollar gum), Salix cinerea (gray willow), and Erica cinerea (bell heather). 
• Griseum, as in Acer griseum (paperbark maple), is another term that relates to gray. 
• When the appearance is distinctly silvery, there’s argentea (-us, -um) and argentatum: think of Potentilla argentea (silver cinquefoil), Salvia argentea (silver sage), and Plectranthus argentatus (silver spurflower, shown below as the variegated cultivar ‘Hill House’).

When one or more parts of a plant appear distinctly dark, there’s…

• Brunnea (-us, -um): brown (e.g., Carex brunnea [greater brown sedge])
• Fusca (-us, -um): dark brown to black, or generally dark or dusky (e.g., Clematis fusca)
• Typhina (-us, -um): dull or smoky (e.g., Rhus typhina [staghorn sumac])
• Nigrescens: becoming black (e.g., Ophiopogon planiscapus ‘Nigrescens’ [black mondo grass])
• Nigra (and niger and nigrum): black (e.g., Gossypium herbaceum ‘Nigrum’ [black-leaved cotton], shown at right)
• Atrata (-us, -um): black (e.g., Aquilegia atrata [dark columbine], which, ok, is actually purple)
• and the prefix “melano-”, as in Salix gracilistyla ‘Melanostachys’ (black pussy willow)

 Next up: a veritable rainbow of other colors.