Kingdom: Plantae
(unranked): Angiosperms
(unranked): Eudicots
(unranked): Asterids
Order: Asterales
Family: Asteraceae
Genus: Leucanthemum
Species: L. vulgare
Binomial name: Leucanthemum vulgare
Syn. Chrysanthemum leucanthemum
Common names: Oxeye daisy, dog daisy, margarite, moon daisy.

Leucanthemum vulgare, the oxeye daisy, is a widespread flowering plant native to Europe and the temperate regions of Asia. It is one of a number of Asteraceae family plants to be called a 'daisy'.
Oxeye daisy is a much larger weed than a daisy. While daisies tend to grow as fairly small, flat rosettes, oxeye daisy usually grows as taller clumps, though still as a rosette at first until it produces upright, leafy flower stems. The leaves of oxeye daisy are quite deeply lobed, different from daisy leaves. The flowers are the same colour as a daisy, with a yellow centre and outer white ray florets. But oxeye daisy flowers are much larger than daisy flowers, usually about 6 cm in diameter. The other two weeds commonly found in pastures with flowers that look like these are stinking mayweed and scentless chamomile, but both of these have very finely divided leaflets. 
Leucanthemum vulgare is a typical grassland perennial wildflower, This perennial weed is most commonly found in waste places, especially along roadsides in many parts of the country. However, it can also be of agricultural importance as it can become troublesome in dairy pastures because cows tend not to eat it. It is never an issue when sheep are present as they are quite keen to eat oxeye daisy.  It is also a problem because it is not susceptible to the selective herbicides normally used in pastures. 
It is a perennial herb 61 cm high by 0.30 m wide. The plant produces an abundant number of flat seeds, without pappus, that remains viable in the soil for 2 to 3 years. It also spreads vegetatively by short rhizomes, which helps make it difficult to control. 
The unopened flower buds can be marinated and used in a similar way to capers.

Oxeye daisy Leucanthemun vulgare-3.JPG

Leucanthemum vulgare. Ox-eye daisy-2.JPG

Oxeye daisy leucanthemum vulgare.JPG

Leucanthemum vulgare Oxeye Daisy-004.JPG

Leaf of Leucanthemum vulgare
Leucanthemum vulgare. Ox-eye daisy-1.JPG

The undersurface of a leaf
Leucanthemum vulgare. Ox-eye daisy.JPG

Another leaf shape
Leucanthemum vulgare Oxeye Daisy-002.JPG 

Leucanthemum vulgare Oxeye Daisy-001.JPG 

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