buttercup oxalis USDA PLANTS Symbol: OXPE
U.S. Nativity: Exotic
Habit: Forbs/Herbs
Oxalis pes-caprae L.

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Taxonomic Rank: Magnoliopsida: Geraniales: Oxalidaceae
Synonym(s): Bermuda buttercup, soursob, sour grass

Appearance
Oxalis pes-caprae is a small perennial herb in the Oxalidaceae (Oxalis family), native to the Cape Region of South Africa. Shoots of O. pes-caprae arise from a short vertical stem that is attached to a pale brown underground bulb. Each bulb (usually smaller than 1 in. [2.5 cm] in size) is capable of producing over 20 small whitish bulblets each year.
Foliage
The trifoliate (clover-like) leaves arise from an enlarged basal stem tip, and are arranged in a loose basal rosette. Petioles are usually less than 4.7 in. (12 cm) long. Each leaflet measures less than 1.4 in. (3.5 cm) in length and are often spotted with hairy lower surfaces.
Flowers
Flowers of O. pes-caprae are bright yellow and are arranged in umbel-like inflorescences. These inflorescences generally have fewer than 20 flowers each, with peduncles shorter than 11.8 in. (30 cm) in height. Sepals of O. pes-caprae are green, less than 0.28 in. (7 mm) long, lanceolate to oblong in shape, and the tips often have two orange or yellow tubercles. The yellow petals are clawed, less than 1 in. (2.5 cm) in length. Each flower has 10 stamens.
Fruit
In North America, O. pes-caprae generally flowers from late fall to early summer, but fruits and viable seed have not been observed in California.
Ecological Threat
Oxalis pes-caprae, although widespread as a garden weed throughout much of California, has never before been observed invading natural areas in North America. It is now reported as invading native coastal dunes in northern California. Due to its extensive occurrence in lawns and gardens, O. pes-caprae has the potential to rapidly spread via the production of bulblets and contaminated soils into adjacent natural areas in California and elsewhere.

Selected Images from Invasive.orgView All Images at Invasive.org


Plant(s);
Barry Rice, sarracenia.com, Bugwood.org
Additional Resolutions & Image Usage

Flower(s);
Barry Rice, sarracenia.com, Bugwood.org
Additional Resolutions & Image Usage

Flower(s);
Barry Rice, sarracenia.com, Bugwood.org
Additional Resolutions & Image Usage

Flower(s); flowers.
Joseph M. DiTomaso, University of California - Davis, Bugwood.org
Additional Resolutions & Image Usage

Flower(s);
Barry Rice, sarracenia.com, Bugwood.org
Additional Resolutions & Image Usage

Flower(s);
Barry Rice, sarracenia.com, Bugwood.org
Additional Resolutions & Image Usage

Foliage;
Barry Rice, sarracenia.com, Bugwood.org
Additional Resolutions & Image Usage

Foliage;
Barry Rice, sarracenia.com, Bugwood.org
Additional Resolutions & Image Usage

Feature(s); bulbs and bulblets.
Joseph M. DiTomaso, University of California - Davis, Bugwood.org
Additional Resolutions & Image Usage

EDDMapS Distribution:
This map is incomplete and is based only on current site and county level reports made by experts and records obtained from USDA Plants Database. For more information, visit www.eddmaps.org
 


State(s) Where Reported invasive.
Based on state level agency and organization lists of invasive plants from WeedUS database.


Invasive Listing Sources:
California Invasive Plant Council