Which of the following plants is a recognized ground cover?

A recognized ground cover is a plant that is effective for covering the ground in a landscape, providing benefits like weed suppression, soil stabilization, and aesthetic appeal.

Gaultheria shallon, commonly known as salal, is a native evergreen ground cover that thrives in shady conditions. Its dense foliage and ability to spread make it an excellent choice for covering bare areas and preventing erosion.

Pachysandra terminalis, or Japanese pachysandra, is another well-known ground cover, particularly in shaded garden settings. It forms a lush carpet of green and is valued for its ability to thrive in less-than-ideal soil conditions, effectively competing with weeds.

Hedera helix, commonly referred to as English ivy, is also classified as a ground cover plant. Its climbing and sprawling habit allows it to cover both vertical and horizontal spaces efficiently, making it a versatile option for filling in areas where other plants may struggle.

Considering the characteristics and functions of each plant, all listed options function effectively as ground covers, thus affirming that every plant mentioned is recognized for this purpose. This comprehensive utility of all the plants supports the selection of the correct answer, which encompasses all three options as valid ground covers.