The Zingiberaceae family numbers around 1300 species distributed in 50 genera. They come from tropical and subtropical areas, mostly from the Old World and with the greatest diversity in Asia (South and South-East). This family used to count the Costus genera which has recently been upgraded into a family of its own, the Costaceae which also encompasses the genera Dimerocostus, Monocostus and Tapeinochilo. Those two families are grouped in what is called a superfamily, the Zingeberiae created in 1990 by W. John Kress. Gingers are close relatives of the genera Musa (banana trees), Canna, Heliconia and Maranta.
What comes immediately to mind for most people who hear ‘ginger' is the image (or taste for that matter) of the rhizome of Zingiber officinale, a world-wide known and used spice with its particular spicy and strong flavour. It is nowadays a common sight in many supermarkets or even street markets as it is use more and more by westerners and a daily ingredient for many an emigrate from tropical countries and its reputation of aphrodisiac plant certainly helped a lot! The aromatic properties of edible ginger as well as of other plants of the family come from essential oils that contain terpenoids and phenylpropanoids. Those properties have been put to use since very old times by people in Asia so various species are used either as food, drugs, colouring agents and even shampoo (Zingiber zerumbet). Another use that will certainly be the favourite of most readers is of course the decorative one, either by growing the plants in the garden or greenhouse of by using cut flowers for bouquets. All species of the family have a common feature; they grow from a rhizome which is an underground stem just like for irises.
The Mascareignes archipelago does not have any endemic species of the ginger family but one is indigenous in Mauritius, Aframomum angustifolium. It belongs to a genera of some 50 species from Madagascar and Africa, this one species is found along streams and shaded areas on the sister island but I never saw it on Reunion. All other gingers have been brought by people coming from Asia for decorative purposes and some have run wild, amongst those the Hedychium have become very invasive plants that are a real threat for local flora, the very same picture as in Hawaii and other tropical locations.
Two species are of commercial importance, Zingiber officinale which as stated above is an every day spice for many Creole people as local food is a mix of European, Chinese, Malagasy and Indian recipes, and turmeric, Curcuma longa, locally known as ‘safran'. The true ‘safran' is saffron, a completely different thing as it is made of the stamens of Crocus sativus but as both give a deep orange colour to food the name is used, sometimes added ‘péï' Creole for the French ‘pays' which means local. Sooo, the part of Curcuma longa which is put to use is the rhizome just like for ginger. It is dug out, put to dry in the sun, sliced and ground until it turns into a bright orange powder that will give a yellow colour to food as well as a particular taste, it also has medicinal properties and researchers have found that users of turmeric have a much lesser rate of bowel cancers than non-users. It is also made into syrups that are an effective remedy to treat colds.
Besides those two commercial gingers we can partake the other ones in two categories; the ones found in the wild and the ones found only in gardens. As stated above several Hedychium which were originally introduced as ornamentals have run out of gardens and established themselves in many parts of the island, mainly wet and partly shaded places like forests understories, creeks banks, ravines and so on. As they do produce a thick creeping rhizome they soon cover large areas thus impeding local plants to grow. They also produce many seeds that are dispersed by streams and birds. Four of them can be seen on the island; Hedychium coccineum which has red inflorescences and blue-green leaves shaped like thin blade, H. flavescens with yellow flowers exhaling a wonderful perfume reminding of Plumeria, H. coronarium has pure white flowers and H. gardnerianum or kahili gingers produces massive flower spikes about a foot long, flowers are yellow with a bright red protruding stamen filament up to 7 cm long. This same species has also invaded Hawaii, Madeira, the Azores, parts of Australia and New Zealand, it seems that once established somewhere it is but impossible to eradicate. They originate from the Himalayan and can withstand temperatures as low as -10°C so they are now grown in Europe and many hybrids have been created. All those will produce a capsule-like fruit with three walls that will open to reveal seeds embedded in a bright red aril very attractive to birds. Another run-wild one is Elettaria cardamomum, the well-known cardamom spice used for tea and cakes. This one has not spread as much as the above plants and is found only rain forests of the Southeast of the island. It produces stems up to 4m (12 feet) high and the minute flowers are to be found at the very base of the plant that is of course where the seeded capsules will be harvested as they are the ones to bear the aroma.
Ornamental species which have kept themselves (so far!) to gardens are Alpinia and Nicolaia. Alpinia purpurata is a very nice plant forming clumps and producing bright red bracts arranged as a cone and hiding the true flowers. A. zerumbet and its variegated form are bigger plants up to 3m (9 feet) with large deep green leaves (white stripped for the variegated) and long pendulous clusters of flowers white with a yellow or red stripped throat. And last but probably one of the most stunning plants, the torch-ginger or porcelain flower, Etlingera elatior (synonymous Nicolaia elatior, Phaeomeria magnifica). This genera includes some 60 species but the porcelain flower is by far the most widely grown of all or cut flowers. It comes from Indonesia, Malaysia and the Sulawesi and is a massive plants with heavy rhizomes producing leafed stems up to 5m (15 feet) high and flowers on leafless stems 1m (3 feet) high, made of red or pink bracts with a white margin, about the size of a grapefruit and lasting for weeks. Young flower shoots are a special dish in Malaysia and Singapore.
I hope you enjoyed this aromatic tour, wish I could hand out some crystallized ginger to make your day sweeter...