Diplotaxis muralis

Diplotaxis muralis

Diplotaxis muralis is a member of the Mustard Family, commonly known as Wall Rocket. It might bear some resemblance to Yellow Rocket (Barbarea vulgaris), but Yellow Rocket is rather bitter, while I think Wall Rocket has a very good mustard flavor. In taste, I would compare it to Purple Mustard (Chorispora tenella), which might actually taste a bit better, but Purple Mustard is only available in the spring and soon turns tough and weedy, while Wall Rocket is available all summer and into the fall. I found it still flowering in the middle of October. 

Diplotaxis muralis exhibits many of the typical characteristics of the Mustard Family, such as the four-petaled yellow flowers, and long thin seedpods growing off the main stem one at a time. The flowers are large enough that you can easily see one of the most distinctive features of the Mustard Family. This is the six stamens, arranged with four long ones, which can be seen projecting slightly out of the flower, and two short stamens, which can be seen just peeking out of the throat of the flower. To distinguish this from other mustards, you should look at the seeds, because yellow mustard flowers are pretty common. The seedpods in the mustard family are called "siliques" and usually have two halves which fall away when mature, leaving a central membrane which often remains on the plant for some time. (This is especially large and noticeable in the money plant.) Diplotaxis is greek for "double arranged" because there are two rows of seeds on each side of the central membrane inside this long thin silique. It also has the female parts of the flower (style and stigma) persisting on the end of the silique. The leaves are mostly at the bottom of the plant, with a few smaller ones on the stem. It tends to grow in dense clumps, so harvesting the good-tasting leaves is fairly easy. It is a fairly common weed is some places. Although it is not native to my area, it is found in more populated areas, in weedy fields and parks.

Diplotaxis muralis leaves

The leaves are the main edible part of the plant. They have a good and fairly mild mustard flavor, but also have a hot/spicy aftertaste. It is usually better to eat them as accompaniment to other foods, so you can get the mustard flavor, while the spiciness is dispersed by eating it in combination with other foods. It is a very good green to put on sandwiches, for example. The stem is too tough to be enjoyable eating, but the flowers and seedpods have the same mustard flavor and are also tender and good to eat. The flowers probably taste even better than the leaves, and make an attractive addition to a salad.