Morphological studies on the genusClematis linn

In four-sepaled flowers ofClematis the sepal is supplied by three main traces. The basic pattern of the vascular supply to sepals is found inC. alpina var.ochotensis which invariably has six-bundled pedicels. It is as follows: the median traces to the first pair of opposite sepals, as well as all the lateral traces, arise directly from pedicel bundles, while those to the second pair are formed secondarily, after fusion and subsequent division of two adjacent pedicel bundles. As to the manner of origin of the median traces, the pattern is similar to that of the vascular supply to foliage leaves. This gives further evidence for the generally accepted view that the sepals ofClematis, like foliage leaves, are decussately arranged. In most other species such asC. apiifolia, C. stans, etc. the number of pedicel bundles tends to be reduced from six to four so as to coincide with that of the sepals, so patterns are much simplified and specialized: all the traces arise directly from pedicel bundles. InC. japonica an iconsistent pattern is observed, since the number of pedicel bundles from which sepal traces arise is much higher and varied.