lemon thyme

Short definition from Wiktionary

Noun

1. 1
   A species of thyme with gold-variegated leaves and a lemon-like scent, Thymus citriodorus or Thymus × citriodorus (there's disagreement as to whether this is a hybrid).
2. 2
   Cultivars of other species with a similar appearance and scent, especially the creeping species Thymus pulegioides.