Skirret

Latin name: Sium sisarum
Plant Family:  Carrot Parsley (Apiaceae)
Lifespan: Perennial
Origin: China
Growing: Does well in full sun or part shade. Very cold hardy and all of my first year skirrets emerged from the soil in the early spring. 
Edibility: Delicious root crop when harvested in the late fall or early winter. They can be eaten raw or cooked and I personally roast them with potatoes. The roots can get tough after the second year so you can peel the outer skin to reduce the toughness. They're sweeter and thinner than carrots and grow in clusters.
Medicinal uses: None that is known.
Permaculture Uses: All members of the carrot parsley family are great for attracting beneficial insects to your garden. Skirret also gets quite tall and can provide great cover for shade loving plants. 
Price: $5 for small starts. $7 for larger plant in gallon pot.