Plant science at the dinner table – Rhubarb

Rhubarb is one of the first plants harvested in Michigan gardens and is an early spring treat. It is technically a vegetable, but in the United States, it is eaten as a fruit. Many people call rhubarb the “pie plant.”

A leafy, dark green plant with thick purple stems sprouting from brown dirt.
Young rhubarb plant. Photo from Pixabay.

Rhubarb is one of the first plants harvested in Michigan gardens and is an early spring treat. It is technically a vegetable, but in the United States it is eaten as a fruit. Many people call rhubarb the “pie plant.” Scientifically, it is an herbaceous perennial with leaves growing off the top of a thick rhizome (underground horizontal stem that produces shoots). The leaf stalks (petioles or leaf stem) are the part of the rhubarb we eat. It is usually used in desserts or an ingredient in sweet dishes, but there are many recipes for savory dishes as well.

Folklore credits Benjamin Franklin with bringing rhubarb to America in the late 1700s. However, it wasn’t until the late 18th or early 19th century that Great Britain and the United States started using it for culinary purposes. Prior to that, it had been cultivated in Asia for over 5,000 years and used for medicinal purposes.

Looking for more fun facts about rhubarb? Michigan State University Extension offers the following:

  • Rhubarb by it’s scientific name is Rhuem rhabararum. Today most plants are hybridized and should be called Rheum x hybridium.
  • Rhubarb is native to Asia, in the cold climates of China, Mongolia and Siberia.
  • Rhubarb leaves are toxic, they contain high levels of oxalic acid. Although poisonous, it would take 9-18 pounds of leaves to be fatal to a 145-pound person.
  • Only the long thick leaf petioles (stalks) are edible.
  • Rhubarb belongs to the buckwheat family Polygonaceae and is closely related to garden sorrel.
  • Washington, Oregon and Michigan are the top U.S. producers of rhubarb.
  • Rhubarb is field grown and grown in hothouses. Total production in the U.S. is about 1,200 acres.
  • Rhubarb needs cold temperatures below 40 degrees Fahrenheit to produce stalks, but only grows when temperatures average less than 75 degrees Fahrenheit.
  • Rhubarb is packed with minerals and vitamins, high in fiber and low in calories with only 15 calories per ½ cup.
  • There are over 40 polyphenol compounds in rhubarb, including anthocyanins, the same disease-fighting compound in blueberries.
  • Cooking rhubarb increases its polyphenol content and overall antioxidant capacity.
  • Research suggests there are beneficial compounds in rhubarb that may fight cancer, lower cholesterol, reduce inflammation, lower blood pressure and protect eye and brain health.

This is a great recipe to try if you are a rhubarb fan. Even if you’re not a rhubarb fan, you might just become one after eating these brownies!

Dark Chocolate Rhubarb Brownies

Adapted from the Endless Meal

Chocolate rhubarb brownies are rich and decadent with the slightly tart flavor of rhubarb which cuts through the sweetness like magic.

Start to finish: 30 minutes (prep time: 10 minutes; cook time: 20 minutes)

Servings: 9


  • 1 cup granulated sugar
  • ½ cup vegetable oil
  • 2 large eggs
  • 1 teaspoon vanilla
  • ½ cup all-purpose flour (can sub gluten-free or almond flour)
  • ⅓ cup cocoa powder
  • ½ teaspoon baking powder
  • ½ teaspoon sea salt
  • 1 cup finely diced rhubarb
  • ½ cup dark chocolate chips
  • ½ cup chopped walnuts or pecans


Preheat your oven to 375 degrees Fahrenheit. Line an 8×8 inch baking pan with parchment paper and lightly butter the paper.

In a medium-sized bowl, whisk the sugar, vegetable oil, eggs and vanilla.

In a large bowl, whisk the flour, cocoa powder, baking powder and sea salt.

Stir the wet ingredients into the dry ingredients and mix them until they are just incorporated. Add the rhubarb, chocolate chips, and nuts, mix until they are combined. The batter will be quite thick.

Pour the batter into the prepared baking dish and spread it out so that it is even. Bake for 20-25 minutes, or just until a toothpick inserted into the middle comes out clean. Make sure not to overcook the brownies so they don't dry out.

Remove the brownies from the oven and let them cool for at least 10 minutes. Cut them into 9 squares

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