A recent post on an international orchid forum dealt with the identification of Cymbidium erythraeum, in particular the form that goes under the name of C. erythraeum 'Paradise'. The poster questioned a plant he had in flower that was a supposed selfing of the 'Paradise' clone. As I had raised several seedling of this same selfing I agreed to put up a sample picture of one of the progeny. So here it is (left).
The 'paradise' clone varies from the ones commonly sold in Australia in that the flower spikes are gently arching or upright, the flowers are slightly smaller, the sidelobes of the lip are rounded and the flowers are widely spaced. The normal form has larger more shapely flowers, the side lobes of the lip are more or less sharply triangular, the flowers are more closely spaced and the flower spike is strongly arching.
The likely explanation for this divergence is the very wide range of the species in it's native habitat. According to Du Puy and Cribb (2007) "it extends from northern India from Kumaon, through Nepal, Sikkim and Bhutan to Myanmar and the western provinces of Shina (Sichuan, Xichang, Yunnan)". Their illustrations clearly show the differences of the plants found at the extremes of its range, Nepal and Yunnan.
One of the other confusing things in many cultivated plants, especially orchids, is the boggling array of hybrids, both natural and man-made, that blur the lines and cause many horticulturalists a great deal of angst. One of these hybrids, Cymbidium tracyanum x erythraeum, is commonly sold as either C. tracyanum or C. erythraeum. Although larger in size than C. erythraeum people not familiar with the 'wild' species can be terribly mislead. For a bit of clarity I have included pictures of C. tracyanum x erythraeum (left and below). This particular plant has as its parents the Indian form of C. erythraeum and C. tracyanum 'FCC'.
A friend of mine does 'artistic' pictures of my plants. You can find a couple of additional pictures of the original C. erythraeum 'Paradise' here. You can clearly see the arching stems and widely-spaced flowers. While C. erythraeum is not the largest or most spectacularly coloured of the Cymbidiums it does have a charm all of its own and a fragrance that is beautiful. One other point in it's favour is that the flowers last for months if the plant is kept cool and out of direct sunlight.
Another interesting site that has pictures of C. erythraeum and a range of other species is Stephen Early's webpage. You can find it here. Check out the individual species but also the "New and Doubtful" section where he deals specifically with the problem listed above. If you are willing to spend a heap of money on a book that is published mainly in Chinese check out The Genus Cymbidium in China by Liu Zhong-jian, Chen Sing-chi, Ru Zheng-zhong and Chen Li-jun in 2006 by www.sciencep.com. They have a few pictures of C. erythraeum as well. Some are mislabeled as C. flavum, which is in fact just an albino form of C. erythraeum.
Du Puy, D. and Cribb, P. (2007). The Genus Cymbidium. Kew Publishing, Royal Botanic Gardens, Kew.