Geranium carolinianum (Carolina Crane's-Bill)

This project collects observations of Geranium carolinianum (Carolina Crane's-Bill) in California for the purpose of facilitating identification and preventing misidentification of this species in iNaturalist.

Geranium carolinianum is a species of flowering plant in the geranium family (Geraniaceae) known by the common names: Carolina geranium or Carolina crane's-bill.

Photo tips:

  • It’s important to get a picture of the entire plant.
  • It's also helpful to get close-up pictures of the face of the flowers, sepals, leaves, and fruits, if present.
  • If there are multiple plants in the picture, it’s helpful to crop your photo to focus on the plant of interest.

How to identify Geranium carolinianum:

  • Stems: The plant has erect stems covered in spiky hairs. The color of the stem is typically pink to red.
  • Leaves: There are two leaves per node on each stem (opposite leaves). There are pointed red stipules at the base of the petioles and branch axils. There is a tendency for the bracts to turn reddish in fruiting state.
  • Flowers: The inflorescence a short, tight cluster of one to several small flowers that grow off the main stems. The five petals are rounded and notched and come in shades of white, light pink, and lavender. G. carolinianum has the lightest flower color of all the small Geraniums. Each flower has five pointed sepals that can be as long as the petals. The carpels have hair and are fused together.
  • Fruits are keeled, have dense hairs and red tips.
  • Habitat: Open to shaded sites, grassland, scrub, forest.
  • Flowering Time: February through August.


Similar species:

  • Geranium dissectum (Cut-leaved Crane’s Bill)
  • Geranium molle (Dove’s-foot Crane’s Bill)
  • Geranium pusillum (Small-flowered Crane’s Bill)
  • Geranium maculatum (Wild Geranium)

How to differentiate G. carolinianum from G. dissectum:

  • G. carolineanum is pale pink, lavender or white; G. dissectum is a darker, vivid pink.


Publicado por truthseqr truthseqr, 14 de janeiro de 2022, 02:06 PM


A friend posted a Geraniuim observation that I found, which he had marked as "carolinianum", but I both wasn't so sure, and had long wanted to work out the distinctions of G. carolinianum, a rare native in my Seattle / Vancouver Puget Trough, primarilly from G. dissectum, introduced here. I spent most of yesterday working on it. Here is what I came up with:

G. carolinianum has flowers that average paler than dissectum, carolinianum medium red-pink to white, dissectum medium pink to a deeper, darker purple-red, with a bit of overlap between color of the 2. Carolinianum has only a shallow notch, or no notch, at the end of the petal. The notches of dissectum average deeper, the deepest deeper than any carolinianum notch I found. The pedicels of carolinianum are shorter than those of dissectum, and roughly as long as the carolinianum sepals, leading to a tighter flower head. Also G. bicknellii has much longer pedicels (and G. columbinum probably longer still). The leaves of dissectum with the narrowest lobes, have narrower lobes than carolinianum leaves with the narrowest lobes, with most dissectum leaf lobe width overlapping with carolinianum leaf lobe widths. Sepals of carolnianum are wider, longer haired, and bend back at the midrib, a feature I found, but didn't find in Hitchcock, or other references. A long tooth at the end of the sepal is about the same in carolinianum and dissectum, but distinguish them from G. molle or G. pusillum, with a tiny tooth, to no tooth, at the end of the sepal. Carolinianum might have longer stipules. I'll have to check some more images for that feature I only suspected after tagging someone that focused on the stipules in his observation photos, getting his reply after looking at all of the western US carolinianum observations.

Not necessarilly different, but notable:
Carolinianum often grows on river edges, making it adapted to other disturbed soils that post-agricultural humans have created, including clearcuts, gravelly road edges, road cuts, lawns, and other naturally disturbed soils, such as upturned tree root soil. One Los Angeles area observer reports it is restricted there to natural chaparral, and grasslands, while, in the eastern US, as well as natural sites, it is adapted to disturbed sites.

Publicado por stewartwechsler 2 meses antes (Sinalizar)

@stewartwechsler, thank you for this detailed analysis. This is very helpful information.

Publicado por truthseqr cerca de 2 meses antes (Sinalizar)

My pleasure!

Publicado por stewartwechsler cerca de 2 meses antes (Sinalizar)

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