In Christmas’s past we’ve explored almonds and marzipan, sugar and glace fruits, frankincense and myrrh, Christmas trees and the rather gothic interpretations of Santa and his flying reindeer. For this Christmas Tchaikovsky’s Nutcracker ballet, a rare celebration of economic botany, provides the botany of Christmas.
First performed in St Petersburg in 1892 the Nutcracker is now a Christmas stalwart. While admittedly unlikely Tchaikovsky’s intention, The Nutcracker devotes a significant part of the stage to economic botany in act two. Here the dancers are associated with the countries of origin of the crops being danced, most obviously with Chinese dancers for tea and Arabian dancers for coffee. Russian dancers for candy canes illustrate that, at least in Russia in the nineteenth century, sugar from sugar beet was cheaper than imported cane sugar, while the Spanish dancers for chocolate reflect the origins of chocolate in Spain’s American empire. Cocoa was first imported to Spain by Hernando Cortez in 1528 and while early Spanish endeavours to cultivate cocoa in the Caribbean failed, Spanish Capuchins successfully cultivated in cocoa in Ecuador in 1635. Even the sugar plum fairy has a richer story than a sweet prune – the plum referring to a prize sweet. Sugar plums were constructed from layers of sugar syrup built around a caraway or cardamom seed and were considered the pièce de résistance of the confectioner’s art. The famous Waltz of the Flowers, the gingerbread mother and even the reed flutes, might all be linked to this first economic botany ballet.
Of course the nutcracker has top billing and deserves the focus of attention. The ballet’s nutcracker is rather more sophisticated than the basic second class lever in most kitchen drawers (- a most unlikely object to insinuate itself into a dream). However, the purpose is the same – to crack the hard shells of the nuts on our Christmas table. Indeed, Christmas was the only time our family had a bowl of unshelled tree nuts and a nutcracker on the table. From memory the mixed nut selection comprised almonds, brazil nuts, hazel nuts and walnuts and, following a substantial Christmas dinner, there was more interest in cracking the nuts than in actually eating the seeds – at least for the kids.
The botany of these nuts deserves some elaboration.
Almonds, Prunus dulcis, are in the rose family with stonefruits and apples and pears, are familiar and grow well in Adelaide – and have been explored previously in the botany of Christmas. The nutcracker has an easy job here.
Brazil nuts are my favourite from a botanical perspective. With some care with the nutcracker the shell cracks sweetly to reveal a large seed. Brazil nuts, Bertholletia excelsis, are in the Lecythidaceae, a family that includes Barringtonia acutangula, a freshwater mangrove from northern Australia and Couroupita guinanensis, the spectacular cannonball tree from Guyana. The Brazil nut tree grows to 50 m, and reputedly to 1,000 years old in tropical rainforests in the Amazon basin and across the Guiana shield.
The Brazil nut tree’s large yellow flowers can only be pollinated by a bee large enough to lift the hood on the flower and with tongues long enough to negotiate the complex coiled flower. Such bees require access to rainforest for survival. For example the small male of the bee Eulaema mocsaryi obtains fragrances which it stores in cavities in its hind legs from the rainforest orchid Cattleya eldorado – this fragrance is essential for attracting females for mating. The large long-tongued female bee is the pollinator for the Brazil nut tree. So the orchids and the bees are required to allow the Brazil nut’s flowers to be pollinated The resulting fruit is a large globose capsule takes 14 months to mature weighing in at up to 2 kg and 15 cm in diameter with a 1 cm thick woody fruit wall. Each fruit contains 8-24 Brazil nuts packed something like the segments of an orange, and after falling to the forest floor are only likely to be opened by an agouti which can chew through the woody fruit wall. The agouti, a small rodent, eats the nuts and stores the surplus by burying them – the lost or excess nuts allowing the establishment of new trees. The complexity of the Brazil nut tree’s ecology means that Brazil nuts are essentially still sourced from wild trees rather than plantations.
Hazelnuts, Corylus avellana, are native to Europe and Western Asia and along with the Corylaceae are now included in the Betulaceae or birch family. Curiously the Betulaceae’s closest relative is considered by molecular taxonomists to be most closely related to the Casuarinaceae – the Australian she-oaks. Hazelnuts are closely related to the filbert, Corylus maxima. Hazelnuts are deciduous and flower in wind pollinated catkins. Hazelnuts grow to 10 m but are perhaps more familiar hedged in European hedgerows. The industry in South Australia is in its early days – most of the world’s production is in Turkey.
The final nut for the nutcracker is the common walnut, Juglans regia in the Juglandaceae or walnut family. The trees are deciduous and flower in catkins that are wind pollinated. The walnut is native from the Turkey through central Asia and as far as south western China. The famed walnut forests of Kyrgyzstan see walnuts growing to 35 m with a trunk up to 2 m in diameter in almost pure stands up to 1,000 years old. China and Iran top the world’s production. In South Australia some walnuts are grown commercially in the Adelaide Hills and Riverland.
If you want to grow any of these nuts pollination’s an important issue. While the Brazil nut’s requirements illustrate an extreme specialisation for pollination, the requirements for the almond, hazel and walnut still require consideration. These nuts are effectively self-incompatible meaning a single tree won’t be sufficient for fruit production – another variety is required for cross pollination.
Our connection with plants infiltrates every part of our lives – well illustrated in The Nutcracker and at the Christmas table!
Stephen Forbes, Director, Botanic Gardens of South Australia
Originally published in The Adelaide Review (Issue 430, December 2015).