Prickly Sow-Thistle

There are several plants that resemble a dandelion in some way, and Prickly Sow-Thistle is one of them. This plant, known in the scientific community as Sonchus asper, is native to Eurasia and the tropical regions of Africa, but has spread to most of the temperate regions of the globe.

The seed-head is different in appearance to that of the common dandelion plant; compare the view, above, to the view in this pic to note the difference. One source says that the plant was given its common name because it is a favorite forage of pigs. Another source says that it was fed to lactating sows because of a milky substance that oozes from the stems when they're broken, in hopes of increasing milk production.

The flowers are similar to that of the dandelion, too, but a close examination will show some differences. The photos below show the morphology of the flowers; the photo on the left is a common Dandelion, and the photo on the right is the Prickly Sow-Thistle:

Note the differences in the leaves in the above photo, as well. The dandelion (on the left) has leaves with rounded lobes, and the leaves only appear at the base of the plant, at ground level. The edges of the leaves on the Prickly Sow-Thistle^[2] (on the right) have jagged, sharp looking "teeth" (although they are not really sharp) and the leaves alternate all the way up the stalk of the plant.

Another difference is that dandelions only have one flower at the top of each stalk. The Prickly Sow-Thistle does that, too, sometimes, but can often have two branches at the top of each stalk, each with a flower. Of course, when the flowers fade and the seed-heads appear, there will be two seed-heads close together:

Although the leaves of this plant are edible by humans as well as animals, similarly to dandelion greens, the Sow-Thistle is considered a noxious weed in many locales because it spreads rapidly as well as depletes nitrogen and water from the soil. So, if you decide to rid your property of these plants, wash the leaves and put them on your salad before disposing of the rest of the plant!