When the Queen asked what was the name of the plant that Laura was holding, she replied, "Mind Your Own Business".
Usually I go to Wikipedia for info, but to keep this TV related, here's some information... information... information... from the BBC's gardening site:
Common Name: Mind your own business
Skill Level: Beginner
Exposure: Full sun, Partial shade
Soil type: Well-drained/light, Clay/heavy, Dry, Moist, Boggy, Sandy
Time to divide plants: April to May
Best known as an indoor plant, baby's tears, or mind your own business, makes an attractive and maintenance-free alternative to grass as ground cover in moist, shady areas. It will tolerate sun or shade. Frost hardy, its leaves are killed by winter frost, but it will recover to grow vigorously in spring. The masses of tiny leaves clothe slender spreading stems that root as they run, forming a dense deep-pile carpet. As it covers the ground it will run over rocks, fallen logs, and so on, clinging to their shape so the features of the landscape are picked out. Quick to establish, it survives periodic dry spells and recovers quickly afterwards. It is a superb substitute for moss in a Japanese garden or shady courtyard. Propagate by division from spring to mid-summer.