The genus Thymus contains about 350
species of aromatic perennial

Perennial plant

A perennial plant or simply perennial is a plant that lives for more than two years. The term is often used to differentiate a plant from shorter lived annuals and biennials. The term is sometimes misused by commercial gardeners or horticulturalists to describe only herbaceous perennials...

 herbaceous plant

Herbaceous plant

A herbaceous plant is a plant that has leaves and stems that die down at the end of the growing season to the soil level. They have no persistent woody stem above ground...

s and subshrub

Subshrub

A subshrub or dwarf shrub is a short woody plant. Prostrate shrub is a similar term.It is distinguished from a shrub by its ground-hugging stems and lower height, with overwintering perennial woody growth typically less than 10–20 cm tall, or by being only weakly woody and/or persisting...

s to 40 cm tall in the family Lamiaceae

Lamiaceae

The mints, taxonomically known as Lamiaceae or Labiatae, are a family of flowering plants. They have traditionally been considered closely related to Verbenaceae, but in the 1990s, phylogenetic studies suggested that many genera classified in Verbenaceae belong instead in Lamiaceae...

, native to temperate regions in Europe

Europe

Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

, North Africa

Africa

Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...

 and Asia

Asia

Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

.

Stems tend to be narrow or even wiry; leaves

Leaf

A leaf is an organ of a vascular plant, as defined in botanical terms, and in particular in plant morphology. Foliage is a mass noun that refers to leaves as a feature of plants....

 are evergreen

Evergreen

In botany, an evergreen plant is a plant that has leaves in all seasons. This contrasts with deciduous plants, which completely lose their foliage during the winter or dry season.There are many different kinds of evergreen plants, both trees and shrubs...

 in most species, arranged in opposite pairs, oval, entire, and small, 4–20 mm long, and usually aromatic. Thyme Flowers are in dense terminal heads, with an uneven calyx

Sepal

A sepal is a part of the flower of angiosperms . Collectively the sepals form the calyx, which is the outermost whorl of parts that form a flower. Usually green, sepals have the typical function of protecting the petals when the flower is in bud...

, with the upper lip three-lobed, yellow, white or purple.

Several members of the genus are cultivated as culinary herbs or ornamentals, when they are also called thyme

Thyme

Thyme is a culinary and medicinal herb of the genus Thymus.-History:Ancient Egyptians used thyme for embalming. The ancient Greeks used it in their baths and burnt it as incense in their temples, believing it was a source of courage...

 after its best-known species, Thymus vulgaris or Thyme Green.

Thymus species are used as food plants by the larva

Larva

A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...

e of some Lepidoptera

Lepidoptera

Lepidoptera is a large order of insects that includes moths and butterflies . It is one of the most widespread and widely recognizable insect orders in the world, encompassing moths and the three superfamilies of butterflies, skipper butterflies, and moth-butterflies...

 (butterfly

Butterfly

A butterfly is a mainly day-flying insect of the order Lepidoptera, which includes the butterflies and moths. Like other holometabolous insects, the butterfly's life cycle consists of four parts: egg, larva, pupa and adult. Most species are diurnal. Butterflies have large, often brightly coloured...

 and moth

Moth

A moth is an insect closely related to the butterfly, both being of the order Lepidoptera. Moths form the majority of this order; there are thought to be 150,000 to 250,000 different species of moth , with thousands of species yet to be described...

) insect species, including Chionodes distinctella

Chionodes

Chionodes is a genus of moths of the family Gelechiidae. Members of this group can be found in most parts of the world. Many species of this genus utilize Douglas-fir as a host plant for their larvae.-Species:Species in this genus include:...

 and the Coleophora

Coleophora

Coleophora is a very large genus of moths of the family Coleophoridae. It contains some 1,350 described species. The genus is represented on all continents, but the majority are found in the Nearctic and Palaearctic regions...

 case-bearers C. lixella, C. niveicostella, C. serpylletorum and C. struella (the latter three feed exclusively on Thymus).

Classification

There has been a considerable amount of confusion in the naming of thymes. Many nurseries use common names rather than the binomial name, which can lead to confusion. For example golden thyme, lemon thyme and creeping thyme can all refer to more than one cultivar. There is some confusion over the naming and taxonomy of some species, and Margaret Easter has compiled a list of synonyms for cultivated species and cultivar

Cultivar

A cultivar'Cultivar has two meanings as explained under Formal definition. When used in reference to a taxon, the word does not apply to an individual plant but to all those plants sharing the unique characteristics that define the cultivar. is a plant or group of plants selected for desirable...

s.
The commonest classification is that used by Jalas, in eight sections:

• Micantes: Iberian Peninsula and north Africa, includes T. caespititius
• Mastichina: Iberian Peninsula, includes T. mastichina
• Piperella: Monotypic section confined to the autonomous community of Valencia, Spain
• Teucrioides: Balkan Peninsula
• Pseudothymbra: Iberian Peninsula and north Africa, includes T. cephalotos, T. longiflorus and T. membranaceus
• Thymus: Western Mediterranean region, includes T. camphoratus, T. carnosus, T. hyemalis, T. vulgaris and T. zygis
• Hyphodromi: Throughout the Mediterranean region, includes T. cilicicus and T. comptus
• Serpyllum: The largest section, throughout whole region, apart from Madeira and Azores, includes T. comosus, T. doerfleri, T. herba-barona, T. longicaulis, T. pannonicus, T. praecox, T. pulegioides, T. quinquecostatus, T. richardii, T. serpyllum, T. sibthorpii and T. thracicus

Species

About 350 species, including:

Thymus adamovicii Thymus altaicus Thymus amurensis Thymus boissieri Thymus bracteosus Thymus broussonetii Thymus caespititius Thymus caespititius Thymus caespititius is dwarf, aromatic mat-forming groundcover shrub, It is native to Portugal, northwest Spain, and the Azores.The plant has narrow, spatula-shaped, smooth leaves to long, fringed with tiny hairs... Thymus camphoratus Thymus capitatus Thymus capitatus Thymus capitatus is a compact, woody perennial native to Mediterranean Europe and Turkey.The plant has with rising stems and narrow, fleshy, oil-gland-dotted, green leaves to long.... Thymus capitellatus Thymus camphoratus Thymus carnosus Thymus carnosus Thymus carnosus is a native endemic to southern Portugal. It is a woody, upright perennial to tall, with clusters of fleshy, oval, light green to grey-green leaves, furry on their undersides.... Thymus cephalotus Thymus cherlerioides Thymus ciliatus Thymus cilicicus Thymus cimicinus Thymus citriodorus Thymus citriodorus Thymus citriodorus, Citrus thyme is a species of the herb, Thyme .Cultivars are selected for aromas of different citrus fruits:...  (Thymus × citriodorus) syn. T. fragrantissimus, T. serpyllum citratus, T. serpyllum citriodorum. citrus thyme Thymus comosus Thymus comptus Thymus curtus Thymus decussatus Thymus disjunctus Thymus doerfleri Thymus fragrantissimus syn. T. citriodorus Thymus glabrescens Thymus herba-barona Thymus hirsutus Thymus hyemalis Thymus inaequalis Thymus integer Thymus lanuginosus Thymus pseudolanuginosus Thymus pseudolanuginosus - commonly called woolly thyme - is now also classified as Thymus serpyllum. It was also formerly known as Thymus lanuginosus. This low-growing creeping thyme with hairy or woolly leaves and stems, can be quite difficult to delineate between other hairy and non-hairy...  syn. T. serpyllum woolly thyme Thymus leucospermus

Thymus leucotrichus Thymus longicaulis Thymus longiflorus Thymus mandschuricus Thymus marschallianus Thymus mastichina Thymus mastichina Thymus mastichina is a species in the Lamiaceae family. It is endemic to the central Iberian Peninsula in Spain.The perennial herb can reach a height of .... Thymus membranaceus Thymus mongolicus Thymus montanus Thymus moroderi Thymus moroderi Thymus moroderi is a small plant from the Thymus genus. It is endemic to some areas in the southern, driest part of the Alicante province along with some isolated and similarly subarid locations in the contiguous Región de Murcia .Thymus moroderi must not be confused with the somewhat... Thymus nervulosus Thymus nummularis Thymus odoratissimus Thymus pallasianus Thymus pannonicus Thymus pannonicus Thymus pannonicus, known by its common name Hungarian thyme or Eurasian thyme is a perennial herbaceous plant, distributed in central and eastern Europe and Russia... Thymus praecox Thymus praecox Thymus praecox is a species of thyme. A common name is Mother-of-Thyme; "creeping thyme" and "wild thyme" may be used where Thymus serpyllum, normally called thus, is not found. This thyme has a strong scent similar to Oregano. It can be used in cuisine or as an evergreen ground cover for gardens.T... creeping thyme Thymus proximus Thymus pseudolanuginosus Thymus pseudolanuginosus Thymus pseudolanuginosus - commonly called woolly thyme - is now also classified as Thymus serpyllum. It was also formerly known as Thymus lanuginosus. This low-growing creeping thyme with hairy or woolly leaves and stems, can be quite difficult to delineate between other hairy and non-hairy...  syn. T. serpyllum woolly thyme Thymus pulegioides  lemon thyme Thymus quinquecostatus Thymus richardii Thymus serpyllum Thymus sibthorpii Thymus striatus Thymus thracicus lavender thyme Thymus villosus Thymus vulgaris Thymus vulgaris Thymus vulgaris or common thyme is a low growing herbaceous plant, sometimes becoming somewhat woody. It is native to southern Europe, where it is often cultivated as a culinary herb.... common thyme Thymus zygis

Sources

• L. H. Bailey; Manual of Cultivated Plants.
• Easter M. Thymus
• University of Melbourne: Thymus