Eurasian Geophytes: A Review

 Geophytes, the specialised stems, are classified as true bulbs, onion bulbs, tubers, corms, and rhizomes. Their scientific exploration heightened attention due to their economic and evolutionary significance. Their morphology and cultivation methods show a wide diversity all over the world. Depending on species and genera, their environmental requirements show differences. Improving cultivation practices and conservation efforts for geophytes is important due to anthropogenic pressure. By recognizing the value of geophytes and implementing effective conservation measures, we can safeguard these botanical treasures for future generations.

The Araceae family comprises a diverse group of plants, the majority of which are found in tropical and subtropical regions. As of yet, 144 genera and 3,645 species have been identified. These plants often exhibit geophytic characteristics, with underground stems such as tubers and rhizomes.

The timing of flowering and fruiting varies among species and climates. Some species flower without leaves at the end of dry seasons, while others follow seasonal precipitation patterns. Although no Araceae species have been reported in true deserts, some, such as Eminium spiculatum subsp. negevense, are found in dry regions, demonstrating the family's adaptability. Despite the limited research conducted thus far, preliminary studies have indicated the potential anticancer properties of certain Araceae plants, including Anthurium, Philodendron, and Dieffenbachia. However, further research is necessary to confirm their efficacy and safety in cancer treatment.

The use of herbal medicine, which employs a variety of plant parts, has a long history in folk medicine. There is a growing interest in the biological effects of these plants. Phytochemicals derived from traditional medicinal plants, including those from the Araceae family, show promise in disease management, including cancer.

This chapter provides comprehensive information on the geophytic properties of plants in the Araceae family and their activity against cancer.

The Amaryllidaceae family is significant, as it includes ornamental and medicinal species. The most common genera found in the Mediterranean are Allium, Galanthus, Leucojum, Narcissus, Pancratium, and Sternbergia. Allium, the largest genus in the Amaryllidaceae family, is distributed in the Mediterranean, Asia, Europe, and North America. The genus Galanthus comprises 19 species native to Europe and Asia. Both Allium and Galanthus are rich in alkaloids and are economically important worldwide. In conclusion, this chapter emphasises the importance of cultivating these species and their endemism rate in Türkiye.

Colchicaceae is a family of angiosperm plants with 16 genera and 161 accepted species, widely distributed in temperate and Mediterranean climates. It has a basal leaf aggregation, reproducing by corms or rhizomes, parallel vein leaves, sessile, petiolate, lamina with stomata, and mesophyll cells with calcium oxalate crystals. Colchicum spp. is a non-cyanogenic plant with toxic alkaloids that are active against gout, have anti-inflammatory and anti-cancer properties, and are used in folk medicines. Corms of all species are nutritive due to low alkaloids and high starch/carbohydrates. Colchicine is a pseudocrocus that is biosynthetically extracted through condensation of tyrosine and phenylalanine to a phenethylisoquinoline precursor. Gloriosa is a perennial climbing tuberous herb that grows in tropical, subtropical areas and Himalayan foothills. It is used to extract colchicine and to treat cancer neuralgic pains, rheumatism, and other diseases. It is also used in horticulture as a cut and garden flower. Chapter 4 reviews the taxonomy of two species and the general characteristics of the plants in this family. 

The Iridaceae family, with 92 genera, is distributed globally, and the family is more common in the southern hemisphere. The main genera are gladiolus, iris, sisyrinchium, crocus, romulea, geissorhiza, babiana, and hesperantha. These genera are important for phytochemical extracts and ornamental value. The Crocus and Gladiolus are mentioned in this chapter. Crocus is a genus of plants that grows naturally in a variety of environments. Türkiye has the largest diversity of Crocus, with more than 80 different species, but they can also be found in regions ranging from Western Europe and North Western Africa to Western China. Gladiolus is currently one of the most significant bulbous ornamental flowers in the world. There are 11 taxa of Gladiolus found in Türkiye. Most of the taxa prevailing in nature are in danger of extinction. Identification of these taxa and their cultivation and protection are important for the genetic pool. This chapter underlines the cultivation of Crocus sativus and Gladiolus cultivation.

Liliacea family consists of 15 genera, which are distributed in the Northern Hemisphere and Eurasia. Fritillaria and Tulip are the most famous genera known all over the world. Fritillaria and Tulipa are the most common ornamental plants. Fritillaria is also valued for its chemical components and is used in conventional medicine. Protection of the wild genus of Fritillaria and Tulip is important for new germplasm against some of the important pests and diseases of these plants. Fritillaria and Tulip cultivation, especially fritillaria cultivation and its development, is important to prevent collection from nature. In this chapter, their taxa in Türkiye, as well as their importance and cultivation, are discussed.

The Orchidaceae family is the world's largest family of flowering plants. Species belonging to the Orchidaceae family have great economic importance as ornamental plants and food raw materials. Orchid species grow naturally in Türkiye. Orchid tubers attract great attention, especially in sahlep production. Collecting orchid tubers from nature for sahlep production causes the extinction of the species. For this reason, it is of great importance to increase knowledge and awareness about the cultivation of sahlep orchids. In this section, information is given about the characteristics of orchid species and the species distributed in Türkiye.

The Zingiberaceae family has many economically important genera. This family contains agriculturally important spices and medicinal plants. Turmeric, ginger, galangal, and cardamom are among the medicinal and aromatic plants that attract great interest worldwide. Although the Zingiberaceae family has different genera, they have similar structures botanically. There are minor distinctive differences between the species. Differences in flowers, leaves, stems, fruits, and active ingredients are important in distinguishing the species from each other. The most important common feature in the Zingiberaceae family is the rhizome root structure. Especially rhizomes, which are both propagation material and harvest products of cultivated species, have high starch content. Rhizomes are offered to the market as fresh, dried, ground, and oil solutions. This chapter includes botanical and agricultural information about some Zingiberaceae genera that have attracted great attention in recent years.