Flower:

Solitary yellow flower head at the end of a stout, hollow stalk. Flowers are typically about an inch across but vigorous blooms can be up to 2 inches and either quite flat or nearly globe shaped. The head is very dense with ray flowers (petals), also described as “ligulate”, referring to the flat tongue-like ray. Each ray is attached to the fertile flower consisting of fused anthers and stigma/style. The bracts are equal in length to the rays they encase and are arrayed in 2 rows, the outermost row spreading out or curled down around the tip of the stalk.

Leaves and stems:

Leaves form a dense rosette around the top of a deep taproot, lance to oblong or spatula shaped in outline, generally 6 to 8 inches long and an inch or so wide but sometimes a vigorous specimen can produce 12 inch long leaves and a whopping 4 inches wide. Leaves are typically hairy underneath, especially along the midrib but can be entirely smooth.

Edges are deeply lobed with sharp, irregular teeth, though this is rather variable, the lobes sometimes varying in size and shape and others more consistent throughout. The terminal lobe usually the largest. Flowering stems are green or purple tinged and are typically smooth or sparsely hairy, more so towards the upper end. Leaves, roots and flowering stems all exude a milky sap when broken.

Fruit:

Fruit is a dry seed, olive green, dull brown or grayish, with a tuft of white to grayish brown hairs to carry it off in the wind.

Notes:

This is without a doubt the most commonly encountered and widely recognized plant species across all age groups and skill levels. It might be so assumed everyone can identify this plant that one might describe it simply as "It's a dandelion!" Linked by a strong cultural history and legacy from salad greens, tea from roots, wine from flowers, yellow prairie sod roofs to #1 hated lawn weed, Europeans have spread this species globally and while very aggressive in human impacted sites it is not overly aggressive in high grade habitat, yet can be expected just about anywhere, as I've found it deep in some of the darkest northern cedar bogs. My grandmother was a devout teetotaller who made dandelion wine for medicinal purposes. It was literally so terrible tasting (recognizing some do a better job than others) it was a strong incentive to not complain about any discomfort in her presence. The common name comes from the French “dent de lion”—tooth of lion—referring to the sharp leaf lobes.

There is a Red-seeded Dandelion (Taraxacum erythrospermum) that is largely indistinguishable from T. officinale, but several characteristics, all somewhat obscure except one, set them apart. Red-seeded Dandelion typically has smaller flowers, rarely over 1 inch across and more consistently deeply lobed leaves, the lobes more triangular to lance-like and consistent in size than Common Dandelion, with the lobe at the tip being approximately the same size as those along its length, though Common Dandelion leaves may also have this appearance. The phyllaries on Red-seeded Dandelion often have a small protuberance just below the tip, where they are rarely present on Common Dandelion. But easily, when fruits are present, Red-seeded Dandelion seeds are clearly red or in variations of purple or brown compared to the dull brown or greenish brown seeds of the more common T. officinale.