Phil Bendle Collection:Oxalis exilis (Least yellow-sorrel)

Kingdom: Plantae 
Division: Magnoliophyta 
Class: Eudicotyledoneae 
Subclass: Rosidae
(unranked): Eurosids 
Order: Oxalidales 
Family: Oxalidaceae
Genus: Oxalis 
Species: Oxalis exilis 
Common name: Least Yellow-sorrel, Creeping oxalis, 

Oxalis exilis is a small New Zealand native perennial weed which has tiny clover to heart-shaped leaves, that form roots wherever the stems touch the ground and grows from stolons (creeping stems)  Creeping oxalis is a common weed of lawns and because the stems creep under lawn runners of Buffalo, Kikuyu and couch, it is hard to eradicate. Seeds are spread by movement of soil and water and lawn mowers. It is typically much smaller than any of the other oxalis species found in New Zealand and is one of the best-adapted oxalis species for surviving constant defoliation within turf.
It has little yellow flowers which are fairly simple in structure with petals radiating. Their bright yellow colour makes the plant obvious at those times of the year when it is flowering.

Creeping oxalis appears to tolerate a wide range of growing conditions. It is typically found in fairly dry, low fertility, open swards. Creeping oxalis has trifoliate leaves (i. e. each leaf has three leaflets), and each leaflet is typically less than 10 mm across. The leave has a distinct notch out of the end of it. It is typically much smaller than any of the other oxalis species found in New Zealand and is one of the best-adapted oxalis species for surviving constant defoliation within turf. The flowers are fairly simple in structure with petals radiating out from a central point.

A photo of turf showing the size of Oxalis exilis yellow flowers (3 in photo)

Closeup of flower  (September)

Oxalis exilis trifoliate leaves

Thanks to Wikipedia for text and information: https://creativecommons.org/licenses/by-sa/3.0/

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