Rhus copallinum – A Name to Remember

Double nerd alert! I have a few passions in my life, one of which is native plants, as you know. Another is grammar and that includes understanding parts of speech and usage (don’t forget to spell your family’s name right on your holiday cards). So I was thrilled to learn something new about words this week when I asked about the species name for winged sumac.

A little background on why I asked: over the years I have developed a little memory trick for myself to help remember how to spell species names in the same genus. Please note that I never took Latin in school (although botanical Latin is quite not the same) but I have vaguely learned that species endings have something to do with gender of the genus and generally match others in the same genus. I’ll use cherry (Prunus) for an example. Black cherry (Prunus serotina) is the one that I remember the best but sometimes I forget if Chickasaw plum is Prunus angustifolius or Prunus angustifolia. So I think back to black cherry and remember it ends in an ‘a’ and therefore it must be Prunus angustifolia.

Winged sumac (Rhus copallinum)

I noticed this week that winged sumac (Rhus copallinum) does not agree with its relatives -- smooth sumac (Rhus glabra) and staghorn sumac (Rhus typhina) -- or it would be “copallina.” I asked why and got the reply that “Copallinum is a non-declinable noun” and to check Weakley 2020 for more details. In that document I found “The Linnaean epithet "Copallinum" (traditionally capitalized) is grammatically a noun in apposition rather than an adjective, and therefore does not change grammatical gender.” A noun in apposition? Off I went to research that.

This is a good source to understand that a noun in apposition is one that further describes the noun but which of course is still a noun itself. Indeclinable nouns are those that don't display grammatical relations with other words in a sentence by means of declension. What we normally have is an adjective that must agree in gender with the generic name (e.g., glabra which means smooth). In searching Weakley 2020, that description is mentioned 5 times; the other four are Nabalus serpentaria, Packera millefolium, Smallanthus uvedalia, and Orbexilum lupinellus.

So this is one that we must just memorize (and I’ll likely not forget it now). If you’d like to know the meaning of the noun copallinum, according to this source: “copallinum means "gum copal" and refers to the resemblance of the dried sap to that of the copal tree.” Several other sources indicate that it is related to the word copalli which means gummy or resinous.

If you’d like to read more about our native sumac species, check out my earlier blog: Sumac – Roadside’s Rowdy Rhus.