Or at least some plants are named after other plants. Specific epithets (the second words of binomial names) that end in “oides” often call attention to similarities to another genus of plants. So Acer platanoides (Norway Maple) is named after the Sycamore genus Platanus because Norway Maple’s leaves are wide like Sycamore’s. Heliopsis helianthoides (Ox-eye Sunflower) is named after the genus of true sunflowers Helianthus. Boltonia asteroides (common names not well agreed upon: White Doll’s Daisy, Starwort, False Aster, or Thousand-flower Aster) does indeed resemble a small Aster. Geum fragarioides (formerly Waldsteinia fragarioides, Barren Strawberry) shares the three-parted leaves & growth habit of Fragaria, the true Strawberries. And Penthorum sedoides (Ditch Stonecrop) looks at least a little like members of the genus Sedum.

Some of these similarities are not very helpful locally: Polystichum acrostichoides (Christmas fern) and Deparia acrostichoides (Silvery Spleenwort) are named for the genus Acrostichum. When Linnaeus first created this genus, it was an extensive genus of ferns in which the sori form a solid mass on the back of the frond. Better samples & clearer views have reduced the genus Acrostichum to 4 species of swamp ferns, only one of which is found in the US, and that no nearer to us than Florida, Hawaii, & Puerto Rico.

The vagaries of taxonomic shifts have given us some oddities: Rue Anemone, formerly Anemonella thalictroides, is now Thalictrum thalictroides, “the Thalictrum that looks like a Thalictrum.” Similarly Southern Mountain-mint, formerly Tullia pycnanthemoides, is now Pycnanthemum pycnanthemoides. “Pycnanthemum” translates as densely flowered, which suits the mountain mints well, but Southern Mountain-mint is no more densely flowered than the others.

Chestnut Oak’s botanic name has shifted from Quercus prinus to Quercus montana, but the older name is still recalled in Quercus prinoides, the Dwarf Chinkapin Oak.

And yes, there are “oides” that are general descriptors rather than references to other plant genera, as Populus deltoides (Eastern Cottonwood, with triangular or delta-shaped leaves) and Populus tremuloides (Quaking Aspen, with trembling leaves). But whenever you see a plant name that contains “oides,” start looking for what that plant is being compared to.

Margaret Chatham

Share this post: