Dandelion :
Ok, so I shared pics of Dandelion flower and root. The entire plant is edible. You can make a coffee substitute from the root, the flowers and leaves are great in salads. Dandelion root is excellent for cleansing the kidneys and liver. Here's some cool recipes for Dandelion greens!
http://www.eatingwell.com/recipes_menus/recipe_slideshows/healthy_dandelion_greens_recipes?slide=1#leaderboardad
Poke Weed
Poke weed is only to be eaten when it's young, and only the shoots and leaves. Poke weed can be very dangerous if prepared wrong, but very yummy! Here's a link with information on how to prepare it.
http://www.eattheweeds.com/can-be-deadly-but-oh-so-delicious-pokeweed-2/
The root is can be used medicinally for Mastitis and Lymph Inflammation, It's also known to help shrink tumors. However, the root should only be used by EXPERIENCED HERBALISTS.
Plantin :
The top picture shows Broad Leaf Plantin ( the brighter, richer color green, the light curling green leaves are Mullein, an herb that's great for Lung ailments.) The bottom Picture shows Narrow Leaf Plantin, both are wonderful for bee stings and colds. The Broad leaf plantin is often eaten like a spinach green.
Purple Deadnettle
Purple Dead Nettle is one of the first green plants of spring. The entire plant is edible, and is great in soups and stews or in a salad. Dead nettle is great for cleansing the liver, and it's known to help stop hemorrhaging.
Coltsfoot
Coltsfoot flowers are often mistaken for dandelions, but upon closer inspection you should notice the differences. Coltsfoot is great for coughs, it's very similar in action to marshmallow. The flowers are edible, as are the young leaves.
I hope this has been helpful, and makes everyone excited for the awesome things nature has to offer. :)