Similar to common thyme but normally with a longer flowering head, more aromatic and without non-flowering, creeping stems. It also tends to flower later but its most diagnostic feature is its stem which is more sharply angled and hairier than other species.
Large thyme is only found in the southern half of Britain, is more restricted to calcareous soils than common thyme, and is rarely found on sandy or gravely soils. It prefers short, open swards but can tolerate coarser, more competitive grasses than its cousin. Pollinated by numerous species of insect and is particularly attractive to bees.