Four-spot Clarkia

Four-spot Clarkia © DSchiel

Winecup Clarkia, Purple Clarkia
Clarkia purpurea ssp. quadrivulnera

Description (Jepson,

  • Eudicotyledon
    • Eudicots are a major lineage of flowering plants; see family for general characteristics
  • Evening Primrose Family (Onagraceae)
  • Annual herb
    • Upright, with green to reddish stems
  • Leaves
    • Narrow, linear to lanceolate
    • Attached directly to the stem (sessile) or with a very short (≤ 0.07 in.) leaf stalk (petiole)
  • Flowers
    • Inflorescence (flower arrangement) from the leaf axils
      • Apparent flower stalk is a long floral tube (hypanthium)
    • Flower parts in fours
      • 4 pink, lavender, purple, or wine-red petals in a cup shape
        • Often (and usually at Edgewood) with a darker wedge-shape at tip and a darker ring at base
      • 4 sepals (usually green, outer flower parts), generally bent back (reflexed)
      • 8 stamens (male flower parts), usually with white to pale-lavender pollen
    • Ovary inferior (below the attachment of other flower parts)
  • Fruit is an elongated, 8-ribbed capsule (a dry, multi-chambered fruit that splits open at maturity)
  • Height to 12 in.


  • Native to California
    • Grows in open grasslands or shrubby places
    • See Calflora for statewide observations of this plant
  • Outside California, grows in western North America from British Columbia south through Arizona and Baja California, Mexico
  • Grows at elevations to 4,920 ft.

Uses (San Mateo County Parks prohibits removal of any natural material)

  • Wildlife
    • Insects are the primary pollinators, but most species of Clarkia are capable of self-fertilization
  • Native people
    • Seeds ground for pinole
      • Pinole is a general term for various flours made from the ground, toasted seeds of wildflowers and grasses, eaten dry or moistened and shaped into balls or cakes (Anderson 2005)
      • “Pinole” is a Hispanic version of an Aztec word
    • Decoction of leaves used as a wash for sore eyes
    • Fields were burned to stimulate the growth of clarkias and other seed-bearing plants (Anderson 2005)
Willam Clark © CPeale

Name Derivation

  • Clarkia (KLAR-kee-a) – named for William Clark (1770-1838) who, along with Captain Meriwether Lewis, led the first transcontinental expedition (1804-1806) at the request of President Thomas Jefferson
  • purpurea (per-PER-ee-a) – “purple,” referring to the color of the flower
  • quadrivulnera (kwad-ri-VUL-ner-a) – from the Latin quadri, “four”, and vulnera, “wounds,” referring to the dark spot on each of the four petals that make them appear wounded


  • Flowers open in the morning and close at end of day
    • This process is an example of nyctinasty, which refers to diurnal and nocturnal changes (single or repetitive) exhibited by the leaves and flowers of some plants (van Doorn 2003)
  • Flowers can self-pollinate (Pollack 2023)
  • Pollen has cobweb-like (viscin) threads
    • Bees in general have specialized electrostatic hairs called scopa (plural, scopae) that store pollen while foraging (Kerstiens 2019)
    • Many bees who visit plants in the Evening Primrose family have evolved modified hairs to handle the sticky pollen characteristic of this family (Portman 2017)
  • Most Clarkia species are strongly protandrous (Raven 1979)
    • Stamens (male flower parts) develop before the pistil (female flower part)
    • The sequential maturation of pistil and stamens is called dichogamy (from the Greek for “divided marriage”)
      • Protogyny describes a pistil maturing before stamens (from the Greek for “female first”)
      • Protandry describes stamens maturing before the pistil (from the Greek for “male first”)
    • Once believed to promote cross-pollination by preventing self-fertilization, dichogamy is now understood to more generally increase the efficiency of sexual functions by preventing mechanical interference (Barrett 2002)
      • Pistil does not interfere with pollen export from the stamens
      • Stamens do not impede contact of pollinator with the stigma (pollen-receiving structure of the female flower)
      • Stigma is not clogged with the plant’s own pollen
  • California has over 70 species and subspecies of plants in the genus Clarkia, named after William Clark, with 20 species found in the greater San Francisco Bay area (Santa Clara County Parks 2020)
    • Some organizations, i.e. San Bruno Mountain Watch’s Mission Blue Nursery and the Golden Gate National Parks Conservancy Nurseries, have renamed the genus Yorkia, to honor York, an enslaved Black member of the expedition (Kilat 2023)
  • Edgewood’s four-spot Clarkia is classified as a subspecies
    • Subspecies indicates a geographically-separated population with distinct morphological characteristics; when not isolated, interbreeding is possible
    • Variety indicates a population with small morphological variations, e.g. color, seen throughout the geographic range of the species; interbreeding is possible
    • In practice, botanists have not consistently applied these ranks

ID Tips

  • May be confused with one other Clarkia species commonly found at Edgewood, ruby chalice clarkia (C. rubicunda)
Four-spot ClarkiaRuby Chalice Clarkia

dark spots at tip and base
darker pink to magenta

often with dark ring at base
Stigma¹does not extend beyond anthers²extends beyond anthers²
Sepals³fused in pairs (or come free)fused in fours
¹Stigma: pollen-receiving part of pistil/female structure
²Anther: pollen-producing part of the stamen/male structure
³Sepals: usually green, outer flower parts
Flower and Seeds © KKorbholz and DSchiel

At Edgewood

  • Found in grasslands
  • Flowers April – July

See General References

Specific References

Anderson, M.K. 2005. Tending the Wild. University of California, Berkeley. Pp. 138, 184, 264.

Barrett, S. 2002. Sexual interference of the floral kind. Heredity 88: 154–159.

Kalit, B. 2023. Five tips for decolonizing language. Golden Gate National Parks Conservancy.

Kerstiens, H. 2019, Apr. 3. Charged electrostatic hairs collect pollen granules. Ask Nature. Biomimicry Institute.

Mitchell, M. 2017. Onagraceae: Evening-primrose family — Clarkia. Monterey County Wildflowers, Trees, and Ferns – A Photographic Guide.

Peale, C.W. 1807. William Clark [Illustration, adapted]. Lewis & Clark National Historic Trail. United States National Park Service. Public Domain.

Pollack, A.S. 2023, May 17. These fabulous flowers are spring’s final encoreBay Nature.

Portman, Z. 2017, Jul. 6. The stickiness of Onagraceae pollen. The Science of Species: Understanding and Identifying the Bees of North America.

Prigge, B.A. and A.C. Gibson. 2013. Clarkia purpurea ssp. quadrivulnera. A Naturalist’s Flora of the Santa Monica Mountains and Simi Hills, California. Web version, hosted at Wildflowers of the Santa Monica Mountains National Recreation Area. United States Department of Interior, National Park Service.

Raven, P.H. 1979. A survey of reproductive biology in Onagraceae. New Zealand Journal of Botany 17: 575-593. Taylor & Francis.

Santa Clara County Parks. 2020. Plants of limited distribution in California. Santa Clara County, California.

van Doorn, W.G. and U. van Meeteren. 2003, Aug. 1. Flower opening and closure: A review. Journal of Experimental Botany 54: 1801–1812. Oxford Academic.