Systematics of genus Ocimum L. (Lamiaceae) in GUL herbarium and its economic importance

In recent years, a new and comprehensive book titled 'Illustrated Flora of Turkey' has been prepared and published. This thesis was prepared to introduce the systematic, geographical, ecological and economic characteristics of the Ocimum L. genus in Türkiye for the aforementioned book. The studies were carried out in 2023- 2025 under field conditions (MAREM, Eğirdir), in the GUL Herbarium and in the Ecological Products Laboratory. The study covers all Ocimum L. taxa found to be grown in Türkiye. Members of the genus are known in Türkiye as; 'Basil, Fesliyen, Festikan, Reyhan, İreyhan, Peslan, Rahan'. Its name is not directly mentioned in the Holy Book Qur'an. It is frequently mentioned when talking about beauty and positive activities in religious sources. It is of Persian origin and Arabic means delicate, elegant, pleasant, fragrant. Reyhan; 'rayiha', meaning 'giving pleasant smell'. The Latin word Ocimum is also derived from the Greek word 'Okimon' meaning 'pleasant smell, aromatic herb'. It is widely used in food, medicine and cosmetics. In some countries, some species are considered sacred and are planted in gardens of places of worship and their consumption for food purposes is prohibited. In Islamic sources, it is the name of one of the gates of heaven that only fasting people can enter. The total number of different samples examined is approximately 50; the total number of collection samples is 150, and the number of cultivars is 35. As a result of the systematic examination of the relevant plants, a total of 15 taxa belonging to 8 species belonging to genus Ocimum are named as cultivars in Türkiye. All samples are preserved in GUL Herbarium (in SDÜ, Isparta). The richest collection in terms of the Ocimum genus among Turkish herbaria is in GUL Herbarium. These samples were identified by us from various systematic sources, some of the unidentified ones were named by us and for the first time. All of them are cultivars in Türkiye, they do not have natural forms. A detailed revision study of this genus is required for Türkiye. According to the order of importance in terms of taxonomy; bract shape, leaf shape, corolla color, hair condition on the plant, color and branching of the inflorescence are important distinguishing characters. The names of some cultivars have been scientifically determined, while some have not been determined. All Ocimum taxa are divided into 2 large groups, Basil and Reyhan, and 8 species. The names given by the public were taken as basis, and appropriate Turkish names were suggested for those whose names were not given. The examined taxa, their Turkish names and distribution numbers according to taxa are as follows: Species are: Ocimum basilicum L., Ocimum minumum L. Ocimum forskolei Benth.,Ocimum americanum L., Ocimum tenuiflorum L. and Ocimum gratissimum L. Ocimum L. sp.-AOcimum L. sp.-B In basil group:Sweet basil (Ocimum basilicum L.: 4, Globe basil (Ocimum minimum L.: 2, Basil Sweet-Thai bacil (Ocimum x thyrsiflorum L.: 2) Yediveren basil (Ocimum forskolei Benth.): 3, Kış basil/Holy basil (Ocimum tenuiflorum L.): 2, Lemon Basil, Hoary Basil (Ocimum americanum L.: 3; in total 4 species, 6 taxa and a total of 16 different cultivars. In Purple Basil group:Arapgir purple basil (Ocimum basilicum L. cf. var. purpurascens: 2, Shiny purple basil: 1, Variegated purple basil: 3, Hairy basil (Ocimum L. sp.) 4, total 10 cultivars. Yanardöner basil (Ocimum L. sp.-A): 1, Ocimum L. sp.-B basil: 1; in total 2 different cultivars related to 2 species. Number of samples of exotic (from abroad) Ocimum taxa: Total 5, the others are local cultivars. All taxa except O. basilicum are new records for Türkiye. Morphological and taxonomic characteristics of the Ocimum genus, species, and culture varieties named in the study were determined, their definitions were made and an identification key was prepared. We have not produced each genotype from seed. According to the results of germination experiments conducted by us; the highest seed germination rate is as follows, respectively: Arapgir basil (73%), Variegated basil 78%; Cinnamon basil (60%); Sweet basil (69%), Globe basil (65%), Yediveren basil (63%) and Winter basil/Holy basil (43%). It grows well in sunny and humid soils with high humidity, up to 1500 m altitude. Its smell decreases in autumn and its biological activity weakens. When the temperature starts to drop below 10°C, it sheds its leaves and dries. In this thesis, the use of Ocimum taxa for economic purposes is also suggested. Local people call the purple ones "Basil" and the green ones "Basil". There is a wide variation among Ocimum taxa both morphologically and chemically. Their odors are diverse. This chemotypic diversity varies according to the cultivar and the habitat. This difference in chemotypic diversity is due to the difference in the composition of the volatile oil. The amount and composition of the volatile oil may vary according to the harvest period. The amount and type of odor change in autumn and summer harvests. The odor of all genotypes decreases in Autumn. In the basil group, the odor is generally low and mostly unpleasant when fresh. However, after drying, the odor intensifies and generally gives a pleasant odor: weet basil, Globe basil, Yediveren basil and Winter basil and Cinnamon basil are deliciously fragrant and strongly aromatic. These taxa are the main genotypes of the genus, their ancestral lineages. It is estimated that the other cultivars emerged by crossbreeding the ancestral lines specified here. The amount of odor is higher in hybrids. In hybridization, whichever ancestral lineage is dominant, the hybrid offspring resembles that genotype in the ancestral lineage more. The oily water obtained by distilling the basil mixed into the cauldron has a pH of 5.40 (acidic); and its oil is light yellow; strong and delicious smelling, easy to drink and appetizing. The essential oil obtained from the purple basil herb is black and the oil ratio is 0.05%. In our experiment, 10 g of essential oil was obtained from 20 kg of herb. Its essential oil is strongly acidic; its oil is black, its oily water is slightly blackish. The oily water of the Yediveren basil is off-white. Both its oily water and its essential oil are strongly aromatic and have high fluidity.