Many plants’ specific epithets describe their leaves, ending in folia (leaf in Latin) or phylla (leaf in Greek). We may immediately recognize the broad-leafedness of plants named “latifolia.” Typha latifolia is common Cattail; Kalmia latifolia is Mountain laurel. But then there are plants named “angustifolia”, usually translated as narrow-leafed: Typha angustifolia is the more salt-tolerant narrow-leaf cattail; Kalmia angustifolia is sheep laurel from the coastal plain. “Angustifolia” comes from the Latin angere to strangle, and is related to angst and anxious. Then there are big leaves, as in Magnolia grandifolia or Eurybia macrophylla (big-leaf aster); splendid leaves as in Physocarpus opulifolius (ninebark) and another name for narrow leaves in Pycnanthemum tenuifolium (narrowleaved mountainmint). And after Kevin Heffernan’s dance, who can forget Oplismenus hirtellus ssp. undulatifolius – wavy leaf basket grass?
Other names compare the leaves of one plant to another that we are supposed to recognize, and sometimes we do! Ambrosia artemisiifolium (common ragweed with leaves like mugwort or wormwood); Antennaria plantaginifolia (plantain-leaved pussytoes); Betula populifolia (gray birch with leaves like eastern cottonwood, Populus deltoides) Clethra alnifolia (sweet pepperbush or summersweet with leaves like Alnus or alder); Euthamia (formerly Solidago) graminifolia (flat-topped goldenrod with leaves like grass); Veronica hederifolia (ivy-leaved speedwell: that invasive little annual that covers the forest floor along with the spring beauties); Viburnum acerifolium and V. prunifolium (maple-leaf viburnum and blackhaw, with leaves shaped like cherry leaves); and Viola primulifolia (primrose-leaved violet).
And some names count leaves or leaflets. Two: Jeffersonia diphylla (twinleaf) and Cardamine (formerly Dentaria) diphylla (crinkleroot or two-leaved toothwort), though here the number reminds us as well that there are two very different kinds of leaves: two narrow, three-part leaves on the flowering stem, as compared to broad, sometimes evergreen three-parted basal leaves.
Three: Arisaema triphyllum (jack-in-the-pulpit); Gillenia trifoliata (Bowman’s root); Staphylea trifolia (bladdernut, and here the “phyl” in the genus name does not refer to leaves: staphyle is Greek for a cluster of grapes, and refers to the fruit); Ptelea trifoliata (wafer ash); and Panax trifolius (dwarf ginseng).
And five: Parthenocissus quinquefolia (Virginia creeper, which hopes you’ll count its five leaflets and not poison it thinking it is poison ivy) and Panax quinquefolius (the real ginseng you were all waiting for).