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succulent leaves of the closely related T. turgidifolia F. Muell., where at least part of the leaves on 
every plant also show a narrow translucent band on the abaxial side (Figure 4). In connection with 
the different position of the water-storing tissue and the chlorenchymc also the innervation of the 
leaves as seen in cross-section is different. In the first case, where a chlorenchymc is absent on the 
abaxial side of the leaves, vascular bundles arc also absent in this part. In the second case, however, 
the primary and secondary vascular bundles lie more or less inside the central water-storing tissue, 
whereas the higher order bundles are arranged circularly at the periphery of the central 
water-storing tissue. This difference in pattern is not surprising, as all Trianthema species arc 
characterized by Kranz anatomy, and the chlorenchymc and the kranzcells lie around the leaf veins 
(Figure 3). In both leaf types a very narrow translucent stripe in the middle of the adaxial side of 
the leaves often is visible, as the vascular bundles (with the chlorcnchyme around) cross only 
occasionally here. It is interesting that both leaf types can also be found in African members of the 
species group. 
A formal taxonomic treatment of the new form of Trianthema triquetra is still hardly possible, 
as long as the whole species group is insufficiently known. It is, however, probably identical with 
T. glaucifolia F. Muell. (type MEL 99963 from Queensland), treated as a synonym of T. triquetra 
by Prescott (1984), but this is difficult to decide on the basis of herbarium material. T. triquetra in 
Australia is variable in other characters (epidermis of leaves and stems, number of flowers per 
inflorescence, seed sculpture, length of the perianth tube, chromosome number), too, which need 
further investigation. At present it is even uncertain whether the name T. triquetra will persist in 
future, as the earlier described species T. salsoloides Fcnzl ex Oliver is rather similar and might be 
an earlier name for the same taxon. In the future, attention should be paid to the differences 
described above in order to obtain more information about the distribution of the different forms. 
Acknowledgements 
This research work was supported by a grant from the Deutsche Forschungsgemeinschaft, for 
which I am very grateful. I should like to thank Dr J. Kadcrcit for improving the English text and 
M. Struck for critically reading the manuscript. 
References 
Bittrich, V. & Hartmann, H.E.K. (19S8). The Aizoaceae - a new approach. Bot. J. Linn. Soc. 97: 239-254. 
Jeffrey, C. (1960). Notes on tropical African Aizoaceae. Kew Bull. 14: 235-238. 
Prescott, A. (1984). Trianthema. In George, A. S. (ed.), "Flora of Australia”, vol. 4, pp. 52-60. 
