[Dent-de-lion (Old French), Pissenlit (French), Taraxacum officinale]
Originating in Eurasia and now infesting lawns worldwide, this common weed is a highly successful member of the vast daisy family (Asteraceae). Its long taproot makes it very difficult to eradicate and its efficient windblown seed dispersal system assures reinfection. It prefers temperate climate and moist soil, which is why it has such an affinity for lawns. The photo specimen leaves were up to 14 inches long. but they are sold up to around 16 inches.
The plant has both medicinal and culinary value. Young leaves are used raw in salads while older ones are more often cooked or added to soups. . Under their bitterness the leaves have considerable sweetness and have a particular affinity for eggs. Roots are used, as are chicory roots, to make a coffee substitute, and flower heads are used to make dandelion wine. The leaves are a strong diuretic, thus the French name Pissenlit (wet the bed). Herbalists consider dandelion a general tonic and "blood cleanser".
More on Lettuce & Chicory
Buying and Storing: Commercial cultivars are likely to be larger and less bitter than those growing in your lawn, but lawn dandelions can be used if picked well before flowering (and if not contaminated with dangerous "lawn care" products). Commercial dandelion can be found in most produce markets. Look for crisp unwilted bright green leaves. Ideally, especially for salads and delicate recipes, they should be about 9 inches long. Loosely bagged and not too wet they will keep in the refrigerator for about 5 days.
Sometimes a variety of chicory, heads of large dandelion-like leaves with thick white stems, is sold as dandelion or "Italian dandelion". Real dandelion leaves are always separate (unless sold attached to the root) and smaller with thin stems. The chicory is, however, quite similar (and closely related)