Portabello mushrooms are actually the mature version of the young, white mushrooms. As they grow, the caps flatten and darken in color, and the texture becomes "meatier".
Portabello mushrooms are a great source of the B vitamins niacin and riboflavin, and are also particularly high in the minerals copper and selenium. Selenium is an important antioxidant that may help prevent chronic diseases such as cancer and heart disease. (See more portabello nutrition facts at Self.com.)
Prepackaged mushrooms can be stored, unopened, in the refrigerator for about one week. Once opened, mushrooms should be moved to a paper bag and refrigerated.
Rhubarb is relatively easy to grow, but needs cool weather to thrive.
The shoots are ready for harvest in the spring, and prime rhubarb season usually lasts for only a few weeks in May or June.