We are so pleased this week to present a special, and wholly unexpected, ‘Takes on Thomson’ submission from Christine Nicholson at Glasgow Botanic Gardens. The Gardens, who also celebrate their bicentenary this year, have registered two new orchid species with the Royal Horticultural Society, delightfully named Dendrobium Bicentenary and Pleione Alexander Greek Thomson.
The Society are hugely grateful to Christine and her colleagues for choosing to recognise Thomson in this way, and it is an honour that we believe to be particularly apt. Thomson was fascinated by nature from a young age, as a child he and his brothers would study books on the natural world and make studious notes and observations during their walks to and from the city. Meanwhile, Thomson’s brother and former business partner, George Thomson, also has an orchid named after him, Pachystoma thomsonianum (George Thomson gave up architecture following an illness and became a missionary, and during his time in Africa he collected plants and sent them to the Royal Botanic Gardens and the British Museum).
Thomson often drew inspiration for his designs from his love of nature, adorning both the interior and exterior surfaces of his buildings with beautiful botanic motifs. It wasn’t just in carved stonework where we see flowers being portrayed, he also incorporated them into cast ironwork and even, as is shown below (left) on the front door of his villa Castlehill, etched onto glass. In fact, the flowers at the top of the etched glass design below are distinctly similar to the new aptly named Pleione Alexander Greek Thomson.
The above images are taken from the Alexander Thomson Society’s survey of Thomson’s residential buildings in Glasgow.
Christine has also very kindly provided us with some notes both on the process of creating a hybrid species and why the Gardens undertaken this, as well as some specific notes on the Thomson orchid, which I append below. Whilst the orchid is not currently in bloom, it is hoped that it will flower in the autumn and be available to view in the orchid house, we will of course provide an update when it is possible to go along and see it. We must take this opportunity to again thank Christine for informing us of her work, for her informative responses and, of course, for helping us to celebrate Thomson’s bicentenary in this wholly unique and charming manner.
Orchid Propagation at GBG
Orchid propagation at GBG is done to back up, conserve and expand the orchid collection. Orchid seed is the smallest in the world and does not have an endosperm – the part of the seed that nourishes the developing embryo in other plants. In the wild orchid seed is dependent on mycorrhizal fungi to provide it with nutrients to enable it to germinate and grow. In cultivation orchid seed has to be sown in sterile, laboratory conditions in flasks of agar based growing medium to provide the nutrients that the mycorrhizal fungi does in the wild.
Many orchids are reliant in the wild on just one species of insect to pollinate them. In cultivation the orchids have to be pollinated by hand to obtain seed. The seed pods can take anything from a few months to a year and a half to ripen. It can take between 3-5 years from seed sowing to flowering.
An application is made to the RHS to register a new hybrid providing details of the seed and pollen parents, when the cross was made, date of first flowering, a description of the plant and photos. Once a hybrid has been registered any subsequent crosses of the same seed and pollen parent will bear that hybrid name.
Glasgow Botanic Gardens has registered orchid hybrids in the past including Dendrobium Festive Glasgow in 1988 and Paphiopedilum Sauchiehall in 1969.
Pleione Alexander Greek Thomson is named to celebrate the bicentenary this year of the Glasgow architect’s birth. The cross, between the hybrid P. Liz Shan x the species P. praecox was made by Glasgow Botanic Gardens former orchid propagator, Mariano Medda and the former curator, Paul Mathews. The seed was sown by Christine Nicholson in December 2011, the first seedlings de-flasked May 2015 and the first plants flowered in 2016.
The seed parent, Pleione Liz Shan is a hybrid between P. lagenaria and P. maculata.
P. lagenaria is a naturally occurring hybrid between P. maculta x P. praecox
P. maculata is found in Yunnan China, Assam India, eastern Himalayas, Nepal, Laos, Myanmar, Thailand and Vietnam. It is a terrestrial growing orchid in cloud forests.
P. praecox is from Yunnan China, India, Nepal, Vietnam, north Thailand and Myanmar. It grows as a lithophyte or epiphyte on mossy rocks and trees in cloud forest.
At GBG the parent plants and the hybrid are grown in cool conditions – minimum 10oC -in a free draining bark based compost with added leaf mould. The plants flower in autumn then have a cool dry rest over winter until new shoots have developed in the spring.
by Scott Abercrombie and Zoë Herbert