Foamflowers in cultivation

Since November 2022, iNaturalist recognizes five species of Foamflowers (Tiarella) in eastern North America. It is difficult to distinguish species in their native habitat, let alone in cultivation. Consequently, every observation of a planted plant should start at genus unless the source of the plant is known and trusted.

For observers

If a plant is planted, be sure to mark it as "not wild". If that plant is left alone, and new plants appear, the new plants are "wild" according to iNat's definition. In a garden setting, however, where plants are seldom left alone (almost by definition), a group of plants may never become "wild", no matter how much the original planting has expanded.

For a long time, the names "heartleaf foamflower" and "Tiarella cordifolia" (and even "foamflower" in some circles) were universally used to refer to the one and only species of Tiarella in eastern North America. That is no longer the case. Strictly speaking, Tiarella cordifolia refers to a narrowly confined taxon distributed along the eastern coastal states of the U.S., from Maryland to Georgia.

If you have information about the source of the plant(s) in cultivation, you may want to add a note or comment to that effect. In most cases, however, the leading ID of the observation should be left at genus (Tiarella).

For identifiers

Identifying Tiarella in cultivation is the ultimate challenge since location information is lacking in almost all cases. There just aren't enough morphological characters to go around. From the identifier's point of view, the best character is the stolon. A photo that clearly depicts a stolon rules out three of the five species. Such a plant (cultivated or otherwise) is either Tiarella stolonifera or Tiarella austrina. The latter has stem leaves while the former does not.

At the other extreme, a plant with lobed basal leaves is probably a cultivar, and therefore not identifiable to species. Such a plant should be kept at genus indefinitely.

Resources

For general information about Tiarella, see: Observing and identifying Foamflowers in eastern North America

To browse photos in iNaturalist or to learn identification tips in Wikipedia, click the links below:

• Tiarella austrina (iNaturalist (Wikipedia)
• Tiarella cordifolia sensu stricto (iNaturalist) (Wikipedia)
• Tiarella nautila (iNaturalist) (Wikipedia)
• Tiarella stolonifera (iNaturalist) (Wikipedia)
• Tiarella wherryi (iNaturalist) (Wikipedia)

Publicado el enero 12, 2023 05:30 TARDE por trscavo