References:The Amazing Dandelion by Selsam & Wexler

http://en.wikipedia.org/wiki/Dandelion

http://www.botanical.com/botanical/mgmh/d/dandel08.html

The Dandelion

They are not native to America

• Dandelions evolved about thirty million years ago in Eurasia

• North Americans are just about the only people who look on the dandelion as a problem. Most of the world thinks of it as a food crop.

• The theory is the dandelion - was brought over from Europe originally as a garden crop and then went native.

Scientific classification

• Kingdom:Plantae

• Division:Magnoliophyta

• Class:Magnoliopsida

• Order:Asterales

• Family:Asteraceae

• Genus:Taraxacum

The English plant name is from the French phrase “dent-de-lion”

• Which means “Lion’s tooth”• Because the leaves have jagged teeth• In Spanish diente de león,

Some other names for Dandelion: • In modern French the plant is named pissenlit, which means

"urinate in bed", apparently referring to its diuretic properties• Also, in the dialect of Veneto, Italy, it is known as pisacan,

which translates to "dog pisses", referring to how common they are found at the side of pavements (source: Giulia Zanetti, native of Veneto),

• In Polish it is called "dmuchawiec" which comes from "dmuchać", "to blow" when in its seed state.

• Hungarian is “kutyatej” ("dog milk", referring to the white sap found in the stem)

Dandelion flower• A bright yellow flower head

• is open in the daytime but closes at night & in the rain

When picking the flowers, a bitter, milky juice exudes from the broken edges of the stem, which is present throughout the plant, and which when it comes into contact with the hand, turns to a brown stain that is rather difficult to remove.

The flower is actually many tiny flowers

• In the family Asteraceae the "flowers" are morphologically a composite flower head consisting of many tiny flowers called florets.

• Try counting the florets in a dandelion flower.• How many do you get? (there should be between 150 & 200 flowers in

each cluster that is the dandelion head)

Also members of the family Asteraceae:

• Daisy

• Thistle

• Lettuce• Chicory• Escarole • Endive

A closer look

Look at an individual dandelion floret

• The ovary is at the bottom• The flower head matures to contain many single-

seeded fruits (achenes).• Above, a circle of fin, silky hairs called a

“pappus” • Each achene is attached to a pappus of fine hairs

(which enables wind-aided dispersal)

A flower beginning to open

• A single petal moves away from the central tube

• The tube is made up of five anthers (sacs of pollen) joined together

• Out of the anther tube a part called the style emerges

• It comes out of the ovary, & the tip of the style is the stigma

New dandelions: many ways

• Insect pollination

• Self pollination

• No pollination- just produces seeds without any pollination!!! (produce seeds asexually by apomixis, resulting in offspring that are genetically identical to the parent plant)

• Roots divide & produce more plants

What is a dandelion seed is actually fruit

The puffy ball

• The pappuses (the silky hairs) grow together• A breeze carries away the parachutes• The pappus opens fluffy in dry air, stays tight

in humid air.• When it hits the ground, the pappus may fall

off & the achene (the fruit with the seed in it), which has hooks on it will grow into a new plant.

Length of stem

• Depends on where it grows-

• In a mowed lawn- it may be 3 inched long

• In weeds, the stem may be 2-3 feet tall!!!

Tap roots

• A dandelion is hard to get rid of

• The tap root with the smaller side branches coming out of it goes down about a foot into the ground

Why it’s a weed to Americans

• As the leaves grow outward they push down the surrounding vegetation, such as grass in a lawn, which kills those plants by cutting off their access to sunlight.

• When lawns are dying all around them, dandelions will be green and vigorous. Dandelions can regenerate from a root or stem, so when the plant is mowed, an individual plant doesn't lose its hold on an area of turf."

Perennial Plants

• Means it lives on from year to year

• The top leaves & stem dies off but the stem lives underground.

• The tap root divides & produces new plants,

• Additionally, one root may get big enough to support several plants instead of just one.

Useful Dandelions

• Fleshy roots are used as food:– Scraped, sliced roots can boiled in salt water like

potatoes– Can be cleaned, baked, ground up & used as a coffee

substitute– Young leaves considered a tasty vegetable & mixed in

salad greens (older leaves are tough & bitter)– Can be cooked like spinach

Interesting stories• Seed houses are developing better tasting dandelions for

consumers- You can buy these in the produce section at the grocery store.

• "Nutritionally, it puts almost all greens to shame," "Capsicums (chili peppers) come close in terms of vitamin A, but those aren't really greens. If you compare dandelion greens to something like spinach, they have twice the vitamin A, twice the calcium, more vitamin C and as much iron.

• It's interesting that one of the greatest nutritional plants is viewed as the lawn's public enemy No. 1."

Interesting stories

• American Indians considered dandelions a medicine

• Dandelion root is a registered drug in Canada, sold principally as a diuretic.

• A leaf decoction can be drunk to "purify the blood", for the treatment of anemia, jaundice, and also for nervousness.

• Drunk before meals, dandelion root coffee is claimed to stimulate digestive functions and function as a liver tonic

Interesting stories

• After a swarm of locusts ate all of the other plants on the island, the people of Minorca, Spain were able to stay alive eating dandelion roots.

Interesting stories

• Scientists tried to use the white sap (latex) that comes out of the stem to make rubber– unsuccessfully with our local species

• But a Russian variety, kok-saghyz, does make rubber.

Interesting stories

• Dandelion flowers can be used to make dandelion wine, for which there are many recipes.[9]

• It has also been used in a saison ale called Pissenlit (literally "wet the bed" in French) made by Brasserie Fantôme in Belgium.

• Another recipe using the plant is dandelion flower jam.

Interesting stories

• The milky latex has been used as a mosquito repellent

• the milk has also been used to treat warts, as a folk remedy

Besides being useful, dandelions are fun

• You can pick a bouquet of flowers

• You can blow the puff ball

• They make lovely flower necklaces