False dandelion is a true weed in the sunflower family | Mystery Plant

True or False…remember those quizzes in school?

False dandelion, Cat’s-ear, Hypochaeris radicata, this week’s Mystery Plant, is all about that. It is called a “false dandelion,” and to understand anything about it, one must know what a “true” dandelion is.

Environment:Less lawn, more trees can make your yard a better carbon storage site

Plants:Golden club likes to stay dry amid watery home | Mystery Plant

Both are members of the sunflower family, and their close relatives include lettuce, chicory, and a bunch of other weedy things, all in the tribe which botanists have named Cichorieae. True dandelion and “false” dandelion are easy to confuse at first glance, but with a bit of observation are very easy to tell apart.

The “true” dandelion that everybody (I hope) knows about is a plant with a taproot and basal leaves in what we call a rosette. The smooth, edible leaves are jaggedly toothed on the margins. Some imaginative French persons used to liken the teeth to those of a lion, and voilà: “Dents de lion,” so that’s where the English common name comes from.

When you pick a dandelion, look carefully for the milky sap which will ooze from the wound. This milky sap is characteristic of  basically all of the members of the previously mentioned tribe Cichorieae, and of course, dandelions and our Mystery Plant. 

When a dandelion blooms, it send up a tender, hollow, leafless flower stalk, always unbranched, with a single head of tiny yellow flowers. That’s right: each one of those little yellow things is a single flower, the way it works in all plants in the sunflower family. 

Each flower has a tiny ovary at the base, which will ripen into a dry, one-seeded fruit (like a sunflower “seed,” only much smaller). At the top of the fruit will be an elongated “beak,” and at the end of the beak will be a series of snow-white, downy bristles.

And of course, when you pick one of these “ripe” heads and blow on it, the parachuted fruits will go flying away everywhere. 

Now for the “false” dandelion. 

It is an accidental import from Europe, now common just about everywhere in the United States. It can be very weedy, and it likes to show up in lawns, especially, sometimes forming impressive blooming stands if not occasionally mowed.

It also has a taproot, as well as a rosette of toothed leaves with toothed margins (but with a hairy surface…like a cat’s ear?), and its tissues contain milky sap.

When it blooms, though, it will send up a rather coarsely wiry stem which is solid, not hollow, and which will be branched, sometimes with up to 8-10 branches, each one of these with a flower head at its end.

The yellow flowers and ultimately ripened “seed heads” are much like those of a true dandelion, except that the parachute bristles are sort of a dirty white. The heads are generally open only in the morning, as they close up after that until the next day. 

Although it is an imported weed, and potentially annoying, I think the flowers in full bloom are very attractive. And, they are prized by pollinators, especially bees.

Give them a chance to do their thing before you haul out that Troy-Bilt.

John Nelson is the retired curator of the A. C. Moore Herbarium at the University of South Carolina. As a public service, the Herbarium offers free plant identifications. For more information, visit www.herbarium.org or email johnbnelson@sc.rr.com.

Never miss a story:  Subscribe to the Tallahassee Democrat using the link at the top of the page.