The Thymus Information Page |
The sectional divisions Section Mastichina is endemic to the Iberian Peninsula It comprises three taxa: T. mastichina, with two subspecies and T. albicans. T. mastichina subsp. mastichina is a very common plant in Spain and Portugal. Its popular name is "mejo-rana silvestre" or wild marjoram. It is a tetraploid (2n=58, 60). The subspecies donyanae occurs only in the southwest of the Iberian Peninsula around the Coto de Donana and in some locations in the Algarve. Its chromosome number is 2n=30. The other species, T. albicans (2n=30) is also found in the southwest in the pinewoods of Pinus pinea. These taxa (T. mastichina subsp. donyanae and T. albicans, 2n=30) are a good example of patroendemism (FAVARGER & CONTANDRIOPOULOS, 1961), and are probably the origin of the tetrapoid apoendemic T. mastichina subsp. mastichina. This new plant has spread throughout the entire Iberian Peninsula. Section Piperella is monotypic with the paleoendemic species T. piperella (2n=28), occuring in the province of Valencia and surrounding areas. Section Teucrioides is endemic to the Balkan Peninsula. It inhabits the mountains of Greece and Albania. Three species can be recognised within this section: T. teucrioides, T. rechingeri and T. leucospermus. These have been studied by HARTVIG (1987)(*) but the chromosome numbers are not yet known. Section Pseudothymbra is an interesting group of 9 Ibero-North-African species, which have very characteristic features: long corollas up to 2 cm, bracts rather different from the leaves and more or less subglobose inflorescences. This section is represented in north Africa by two species: T. bleicherianus and the common and very variable T. munbyanus, which inhabits a large area extending from the Middle Atlas and the Rif Mountains as far as the Algerian mountains. There are some problems with this species. Usually it is possible to recognise two subspecies. However in some cases it is very difficult. Probably hybridization takes place and there exist intermediate forms between this species and T. algeriensis from section Hyphodromi subsection Subbracteati and T. wilidenowii from section Thymus. T. bleicherianus is only know from three locations, one in Algeria and two more in the north of Morocco. The other species of this section are all Iberian. T. lotocephalus (2n=30) is an endemic of the Algarve. T. villosus occurs in southwest Spain (Cáceres, Toledo and Ciudad Real provinces) and Portugal. Four species are found in southeast Spain: T. longiflorus, T. membranaceus, T. moroderi and T. funkii. Their chromosome numbers are 2n=28. T. antoninae (2n=56), an apoendemic in the sense of FAVARGER & CONTANDRIOPOULOS (1961), is an anomalous thyme in this section (subsection Anomalae), without bracts and with lax inflorescences, but it has a very long calyx and corolla. Section Thymus is found only in the western Mediterranean region. The most important species are T. vulgaris, T. zygis and T. willdenowii. The first one is distributed in northern Italy, southern France and the eastern half of Spain. It usually occurs on basic soils. Its chromosome numbers are 2n=28, 30; or 2n=58 for the subspecies aestivus, which inhabits the Valencian region and Ibiza, and flowers later than the subspecies vulgaris. T. zygis is a very common species in the Iberian Peninsula, with three subspecies: subsp. gracilis (2n=28), that occurs in southeast Spain and also in Morocco; subsp. zygis (2n=28) from the north half of the Iberian Peninsula; and subsp. sylvestris (2n=56), a tetraploid, that occurs in the southwest quarter. T. willdenowii (2n=30) is common in north Africa (Morocco and Algeria) and also grows in Gibraltar, its only locality in Spain. This species probably produces hybrids with T. munbyanus and T. algeriensis. The other species of this section are: T. capitellatus and T. camphoratus of Portugal, both with a 2n=30 chromosome number, T. carnosus (2n=56), that only grows on coastal sand dunes in the southwest, T. orospedanus (2n=28) which is probably of hybridogenous origin, T. baeticus (2n=58), that occurs in the south of Spain, T. loscosii (2n=54), an endemic of the Ebro basin, and T. serpylloides, that grows in the Penibetic and Betic mountains. Only T. hyemalis occurs in the coastal regions of the southeast of Spain and also in northern Morocco. Section Hyphodromi extends throughout the Mediterranean area and comprises around 60 species. Three subsections can be distinguished in this section: Subbracteati, Serpyllastrum and Thymbropsis. Subsection Subbracteati is characterized by more or less revolute leaves and seems to be Oriental. Only one species occurs in north Africa, from Morocco to Libya: T. algeriensis (2n=30, 56), and another species occurs in Central Spain: T. mastigophorus (2n=28). T. spinulosus (2n=56) occurs in Sicily and Italy, and T. striatus (2n=26, 28, 42, 54, 56, 84) in the Italian and Balkan Peninsulas. Both species vary in shape. The leaves of the second species vary from linear to lanceolate. T. argaeus, T. brachychillus, T. cappadocicus, T. cherlerioides, T. convolutus, T. pulvinatus and T. revolutus occur only in Turkey; T. boissieri, T. dolopicus and T. plasonii only in the Balkan Peninsula; T. atticus, T. parnassicus and T. leucotrichus inhabit Turkey and the Balkan Peninsula. The latter species also grows in Syria and in the Lebanon. T. integer is only found on the island of Cyprus. This species is probably not different from T. leucotrichus. T. samius occurs in the Aegean islands. T. borsthenicus and T. pallasianus occur north of the Black Sea, T. persicus south of the Caucasus, but only one location for this species is known. Subsection Serpyllastrum is a group of species characterized by prostrate stems and flat leaves, the latter being more or less wide. It is well represented in Spain by five species: T. bracteatus (2n=56, 58), T. leptophyllus (2n=28, 56), with three subspecies, one of them (subsp. izcoi) is in some cases near to forms of T. praecox and very difficult to distinguish from it. The remaining three are T.fontqueri (2n=56), T. granatensis (2n=28) and T. lacaitae (2n=28). It is also well represented in the east, but no species occur in Italy and north Africa. T. aznavourii, T. bracteosus and T. comptus (2n=26, 28, 52) occur in the Balkan Peninsula; T. canoviridis, T. haussknechtii, T. pectinatus and T. sphatulifolius are found in Turkey. T. zygioides (2n=56, 60, 62, 90) extends from the Balkan Peninsula as far as the Crimean Peninsula and is also found in Turkey. This species and the Spanish endemic T. lacaitae are morphologically very similar. There is also a group of species that occur only in the Caucasus: T. dagestanicus (2n=28), T. hadzhievii (2n=28), T. helendzhicus, T. karjagnii, T. ladjanuricus, T. lipskyi, T. madjopiensis (2n=28) and T. sostiowskyi (2n=60). Seven species more from central Asia are considered as part of this subsection although there is some doubt. Subsection Thymbropsis includes the north African T. broussonetii, T. maroccanus, T. lanceolatus, T. numidicus, T. pallescens, and the two endemic species from Greece T. laconicus and T. holosericeus (2n=28). Five more species from this section are found in Turkey: T. cariensis, T. cilicicus, T. eigii, T. leucostomus and T. sipyleus. T. syriacus (incl. T. neurophyllus) ocurrs in the Lebanon, Syria and a location in northern Iraq; T. bovei is found in the Sinai Peninsula, Israel, Jordan, Iraq and Saudi Arabia; and T. decussatus in Sinai and Saudi Arabia. This subsection appears to be a group of species predominantly north African and west Asian. Section Serpyllum appears to be the oldest in the genus. Around 124 species belong to this section. They occur throughout the area of the genus, except in Madeira and the Azores. It is in this section that we find the biggest chromosomal variation. There are also woody species that grow in the mountains in arid areas e.g. T. origanoides in Lanzarote (Canary Islands), T. serrulatus and T. schimperi in Ethiopia and T. laevigatus in the southwest of the Arabian Peninsula. Another group of species are more or less herbaceous and occur in the Mediterranean mountains and the rest of Eurasia as far as Japan and also along the coasts of Greenland. The species of the last group seem to be younger in evolutionary terms and have probably been actively evolving since the last glaciation when this group colonized the new lands free of ice. This group is also very difficult taxonomically and corresponds to the three last subsections. Few species of these subsections are present in the Mediterranean area. JALAS ( 1971) divided this section into 7 subsections. Subsection Insulares comprises T. willkommii (2n=56), an endemic species which occurs in the mountains of the provinces of Castellón and Tarragona (eastern Spain), T. richardii, with three subspecies: subsp. richardii (2n=28, 30) from Mallorca and Yugoslavia, subsp. ebusitanus (2n=30) from Ibiza and subsp. nitidus (2n=28) from Marettimo island near Sicily. The subsection also includes the north African T. dreatensis and T. guyonii, the Canary Island T. origanoides and the endemic species of northwest Turkey T. bornmuellerii. Subsection Pseudopiperellae comprises T. herba-barona from Mallorca (2n=28), Corsica (2n=56) and Sardinia (2n=84) (MAYOL & al., 1990) and T. nitens (2n=28) from the South of France. Subsection Kotschyani includes many Asian species, but only T. fallax and T. transcaucasicus occur in Turkey. Other interesting species occuring outside the Mediterranean area are T. laevigatus from the mountains of Yemen and T. schimperi (2n=c.30) and T. serrulatus from the Ethiopian Mountains. Five species found in the Balkan Peninsula belong to the subsection Isolepides: T. bulgaricus, T. glabrescens (2n=28, 32, 52, 56, 58), T. longedentatus (2n=30, 90), T. pannonicus (2n=28, 35) and T. sibthorpii (2n=28). The following subsections are not well represented in the Mediterranean area; only they have a few species that usually are found in the mountains in this area. Subsection Alternantes includes the species T. pulegioides (2n=28, 30) and T. froelichianus (2n=56) from the European countries of the Mediterranean basin, T. alpestris (2n=28) from France and Spain, T. oehmianus from Yugoslavia; and T. bihoriensis and T, comosus (2n=28, 58) from Rumania. Subsection Pseudomarginati includes the species T. longicaulis (2n=26, 28, 30, 50, 56, 58) and T. praecox (2n=24, 28, 50, 54, 56, 58), present in all the northern countries of the Mediterranean basin and also in Turkey. T. nervosus (2n=28), an endemic of the Pyrenees and the French Massif Central, T. ocheus, T. stojanovii and T. thracicus are from the Balkan Peninsula, the latter also being found in Turkey. Subsection Serpyllum includes the European T. serpyllum and T. talijevii, T. quinquecostatus from Japan, and many species found in Asian Russia, it is not represented in the Mediterranean area. |