In a previous edition under the heading of P. pseudocerasus, I gave a short description of a cherry, based on a specimen labelled by that name, which is preserved in the Lindley herbarium at Cambridge University. I there observed that the true P. pseudocerasus was probably not then in cultivation and that the trees grown under the name in gardens were mostly forms of P. serrulata. In February 1917 there flowered in the Cambridge Botanic Garden a cherry which, after being critically examined by the late Mr R. I. Lynch, the Curator, and compared with Lindley’s specimen, was considered by him to be the true thing (see Gardeners’ Chronicle, August 4, 1917, p. 47). I was afterwards furnished with flowering and leaf-bearing shoots and concurred with Mr Lynch’s verdict. The flowers are pink, 3⁄4 to 1 in. wide, produced on shortly stalked racemes three to six together; petals scoop-shaped, 3⁄8 in. long, scarcely as wide, notched at the apex; anthers yellow; style and ovary glabrous. Calyx-tube 3⁄16 in. long and, like the flower-stalks, slightly hairy. The fruit is bright red, rather larger than the British wild cherry. The Cambridge tree is reputed to date back to Lindley’s time and as the specimen in the herbarium is labelled “P. pseudocerasus” in Lindley’s own handwriting, it was by most people concluded that the mystery of the cherry of that name was solved.
A flowering spray from the Cambridge tree has lately been figured in the Botanical Magazine, t. 9129, and Dr Stapf, the editor, whilst agreeing in the accompanying text that it matches Lindley’s specimen, refused to agree that the latter is the true P. pseudocerasus, although it is labelled by Lindley himself. He pointed out that it does not match the Botanical Register plate (t. 800) which, in the absence of a co-related specimen, constitutes the only available evidence of what P. pseudocerasus really is. (It may be pointed out that although the Botanical Register picture is legended as “Prunus paniculata, Thunberg”, the plant so called by Thunberg is really Symplocos crataegoides and not a prunus at all. It was to replace this erroneous name that Lindley substituted “P. pseudocerasus” for it. The figure, therefore, constitutes the standard on which the identity of the species is based.) Dr Stapf calls the Cambridge tree P. cantabrigiensis, and, if he is right, P. pseudocerasus remains as forlorn a mystery as ever, having appeared in the year 1819 as an introduction from China by a nurseryman called Samuel Brooks of Ball’s Pond, Newington Green, London; flowered in the spring of 1824 in the Horticultural Society’s Garden at Chiswick; been figured in the Botanical Register under a wrong name; and never been recognised since, either wild or cultivated.
P. cantabrigiensis is very hardy and flowers often in February. In the milder parts of the country where it had a chance to develop its flowers uninjured by frost it should be a handsome tree valuable for the exceptional earliness of its blossom.
To the above account, which is taken almost unchanged from previous editions, there is little that can usefully be added, except that two authorities on the oriental cherries, E. H. Wilson and C. Ingram, have both pointed out that the discrepancy between the Lindley specimen and the plate in the Botanical Register is of no account. The drawing in the plate was made from a plant which had flowered in the fruit-house of the Horticultural Society, and shows a shoot on which leaves and flowers appear together and the peduncle is much elongated, while in Lindley’s specimen the peduncle is very short and the flowers precocious. But the length of the peduncle in this group of cherries is a fluctuating character, depending on the conditions under which the plant is grown and the season, becoming abnormally elongated if the flowers are produced when the leaves are almost fully expanded. But the name P. pseudocerasus has been so widely used in the past for other cherries that it is best discarded as of uncertain application.
The Cambridge cherry is very closely allied to P. involucrata Koehne, a cherry cultivated in China for its fruits and described from a specimen collected by Wilson in W. Szechwan.