
Sun Cups, Golden-eggs
Taraxia ovata
NATIVE
Description (Jepson, PlantID.net)
- Eudicotyledon
- Eudicots are a major lineage of flowering plants; see family for general characteristics
- Evening Primrose Family (Onagraceae)
- Fleshy, low-growing perennial
- Grows from a thick taproot
- Leaves are wide and wavy-edged, with pointed tips
- Arranged in a basal rosette
- Prominent white or reddish central veins
- Flowers
- Inflorescence (flower arrangement) of single flowers atop long floral tubes
- Flower parts in fours
- 4 bright yellow petals
- 4 sepals (usually green, outer flower parts), which fold back (reflex)
- 8 stamen (male flower parts), with cobweb-like, sticky pollen
- Pistil (female flower part) with prominent ball-shaped stigma (pollen-receiving structure) slightly extending the stamens
- Typical flower stem is absent
- Instead, the hypanthium (floral cup formed from the fusion of petals, sepals, and stamens) lengthens into a long, sterile tube (≤ 6 in.), which encloses an extension of the ovary
- Ovary inferior (below the attachment of other flower parts)
- Fruit is a capsule (a dry, multi-chambered fruit that splits open at maturity) that retains the long, sterile extension of the ovary tip

Distribution
- Native to California
- Grows in grasslands, generally in clay soil
- See Calflora for statewide observations of this plant
- Outside of California, grows on the southwest coast of Oregon
- Grows at elevations to 5,600 ft.
Uses (San Mateo County Parks prohibits removal of any natural material)
- Wildlife
- Pollen source for select species of small bees (Wagner 2007)
- Pollen has cobweb-like (viscin) threads
- Many bees who pollinate plants in the Evening Primrose family have evolved specialized hairs to transport the sticky pollen (Thorp 1979)
- Pollen source for select species of small bees (Wagner 2007)
- Native people
- Ate the leaves raw, boiled, or steamed
Name Derivation
- Taraxia (tar-AX-ia) – referring to the leaves, which are similar to those of hawkbit, Leontodon taraxacoides (now L. saxatilis), in the Sunflower family
- taraxacoides – from the Greek for “resembling taraxacum,” the genus of the common, non-native dandelion
- taraxacum – from the Greek taraxia, of disputed origin, possibly from the Persian for “bitter herb” or the Greek for “eye-disorder cure”
- taraxacoides – from the Greek for “resembling taraxacum,” the genus of the common, non-native dandelion
- ovata (oh-VAT-ah) – from the Latin ovatus, “oval,” from ovum, “egg,” referring to the oval-shaped leaves or petals
- Sun cup – a number of species in the Evening Primrose family with yellow flowers share the common name sun cup
Notes
- Flowers in this genus open at dawn
- Species in the Evening Primrose family open either at dawn or dusk
- 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)
- Because yellow flowers reflect ultraviolet light more strongly than flowers of other colors, they attract pollinators, like bees, that perceive ultraviolet light (Klomberg 2019)
- The fertile part of the ovary is often underground
- Location may protect the developing fruit from browsers (Mitchell 2017)
- Ants or cracks in the clay soil, where it frequently grows, may aid seed dispersal (Corelli 2005)
- Since 1840 this species has been placed in various genera, including Oenothera, Taraxia, and Camissonia
At Edgewood
- Found in grasslands
- See iNaturalist for observations of this plant
- Flowers February – June
Specific References
Cane, J.H. and S.D. Sipes. 2006. Characterizing floral specialization by bees: Analytical methods and a revised lexicon for oligolecty. N.M. Waser and J. Ollerton (Eds.). Plant-Pollinator Interactions: From Specialization to Generalization. University of Chicago Press, Chicago, Illinois. Pp. 99-122.
Klomberg, Y., et al. The role of ultraviolet reflectance and pattern in the pollination system of Hypoxis camerooniana (Hypoxidaceae). AoB PLANTS 11(5). Oxford Academic.
Mitchell, M. 2017. Onagraceae: Evening-primrose family — Suncups & primroses. Monterey County Wildflowers, Trees, and Ferns — A Photographic Guide.
Thorp, R. 1979. Structural, behavioral, and physiological adaptations of bees (Apoidea) for collecting pollen. Annals of the Missouri Botanical Garden 66: 788-812.
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.
Wagner, W., P. Hoch, and P. Raven. 2007. Revised classification of the Onagraceae. Systematic Botany Monographs 83: 1-240.