Cocculus

Abstract: Summary. The surface-patterns on the endocarps of Cocculus are described and illustrated with SEM photographs. The value of these patterns in the taxonomy of the genus is discussed. Important taxonomic characters are provided by the form of the fruit and endocarp in the Menispermaceae. In some parts of the family, especially in the tribes Cocculeae and Tinosporeae, a remarkable variety of raised ornamentation on the surface of the endocarp is developed and the patterns formed by these projections are often quite distinctive for different genera and species. These patterns, however, are hidden within the fruit and in order to reveal the surface of the endocarp some simple preparation is necessary. It is no doubt partly for this reason and partly because of the difficulty of describing details of the ornamentation precisely in words that this character has not been used as much as it might have been. Information about these ornaments can clearly be better conveyed by illustrations. Miers in his monograph of the family (Contrib. Bot. 3 (1871)) paid some attention to endocarp characters, which were illustrated in many of the plates. The finer detail, however, is not clearly or always accurately depicted. Some further illustrations were provided in Diels's monograph in Engler, Pflanzenr. IV, 94(1910). Features of the endocarp were used in the descriptions and keys in my account of the Malesian species of Stephania in Kew Bull. I I: 41-69 (1956). The present account offers an illustrated review of the endocarps of Cocculus DC. as an example of the range of endocarp patterns occurring in one genus. Concurrently with this investigation a survey of leafepidermal characters of Cocculus was carried out by Dr. D. K. Ferguson, the results of which appear on pp. 485-488. Illustrations of the endocarps and leaf-epidermis of this genus will be of particular interest to palaeobotanists in view of the fossils of these parts which have been referred to Cocculus and to related genera. METHODS The fruits were first boiled in water for a few minutes to soften the pericarp, which could then be removed with a fine pair of forceps. As much as possible of the soft tissue adhering to the surface of the endocarp was picked off with the forceps. Then the endocarp was brushed clean with a stiff nylon brush of the type used in a dentist's drill; plenty of water should be used in this operation. (It should be noted that this brushing technique is only suitable for endocarps which do not bear delicate processes which can easily be broken off by the stiff bristles.) The endocarps were left to dry exposed to the air for an hour or so before being placed in paper envelopes. They were then left to dry further for at least several days in the dry atmosphere of the Kew Herbarium. In order to obtain photographs with a large enough depth of focus, a scanning electron-microscope was used. The relatively large size of the