Zingiberaceae, the ginger family, is a family of flowering plants containing 58 genera and about 1600 described species distributed globally in the tropics and subtropics. They are aromatic perennial herbs with creeping rhizomes, sometimes tuberous. Basal leaf sheathing forms a pseudostem taller than their true stems which emerge unbranched. Flowers are typically zygomorphic (bilaterally symmetrical) and inflorescence is raceme. Fruit is typically a dry capsule and seeds are arillate.
Ancient fossils and phylogenetics indicate the Zingiberaceae evolved in Africa during the mid-Cretaceous period. The dispersal of these plants across Asia, the Americas, and Australia followed the expansion of tropical rain forest habitat soon after this period.Habitat conservation is important for local cultures and economies in Thailand and its surrounding region, where Zingiberaceae species are grown for food, medicine, and socio-religious activities. thumb|Zingiber officinale rhizome]]
Leaves and stems
Members of the family are small to large herbaceous plants with distichous leaves connected to basal sheaths that overlap to form a pseudostem, or 'false stem'. True erect vegetative stems are short, thin-walled and always unbranched. Horizontal underground stems are rhizomes, see description and photo below. Leaves are alternate, 2-ranked, entire, elliptic, with prominent midribs.
Distribution
Zingiberaceae family members have pantropical distribution primarily in the tropics of south and Southeast Asia, however their entire distribution spans across Asia, Australia, Africa and the Americas. Most species can be found in forests and around 20 species are cultivated for domestic use.
Different genera show variance in their distribution across forested habitats and cultivated areas. A report in Thailand showed the genera Globba, Curcuma, and Kaempferia represented high diversity in both habitat types, whereas genera such as Cornukaempferia and Hedychium were absent in the forest. The earliest known fossils of the family belong to the Campanian age (late-Cretaceous) and are from the genera Spirematospermum in Germany,Tricostatocarpon and Striatornata in Mexico, and Momordiocarpon in India. Spirematospermum chandlerae from the Santonian of North Carolina was previously classified in the Zingiberaceae, but more recent studies support it belonging to the Musaceae.
Conservation
Tropical southeast Asia is an area of crucial importance for conservation efforts. Zingibereaceae species are threatened by deforestation and forest degradation in this region of high species diversity and endemism. A conservation report on the zingiberaceae recorded nearly 300 threatened species out of roughly 14,450 species assessed. Most of the threatened species put at risk by anthropogenic factors and few species that are threatened by natural disasters volcanic eruptions and tsunamis. The future of on-site conservation involves population monitoring and management to ensure the continued reproduction and adaptation of Zingiberaceae species. For the species close to extinction, ex situ conservation approaches such as propagating and sustaining species outside their natural ecosystem is a better approach. Botanical gardens and genebanks serve to increase the chance of survival by avoiding natural threats before restoring populations back in the wild. Many of these spices contain either of the bioactive compounds ginger or curcuminoid, both of which are used for therapeutic affects as anti-inflammatory and antimicrobial agents. Several commercially and culturally important aromatic medicinal plants in this family are native to India, including Alpinia calcarata and a wide diversity of 40 Curcuma species. In regions, such as Saraburi Province, Thailand, where many species of the Zingiberaceae are home to, these plants have cultivated rich cultural traditions and economic growth, propelling a need for their habitat conservation.
Ornamental genera include the shell gingers (Alpinia), Curcuma, Hedychium, Kaempferia, and torch-gingers (Etlingera). Some genera yield essential oils used in the perfume industry (Alpinia, Hedychium).