Morphological variation of cleistogamous (CL) flowers were examined in Lespedeza tomentosa (Thunb.) Siebold ex Maxim. The CL flowers always have five petals although their size is reduced, and they vary in numbers of stamens and pollen sacs due to reduction. The numbers of stamens per flower and pollen sacs per anther vary from ten to six and from four to zero, respectively. The inner whorl (antepetalous) stamens tend to be reduced more conspicuously than the outer whorl (antesepalous) ones and the abaxial stamens than the adaxial ones within the same whorl in the CL flower. The two antesepalous stamens located on the most adaxial position are always retained and produce fertile pollen sacs in CL flowers. The position of these stamens is closely related to self-pollination, because the stigma comes to contact with them by the adaxially curved style. Moreover, degree of such reduction in the CL flower is closely related to the form of inflorescence to which the flower is attributed and to the position within the inflorescence.

This paper focuses on the following three evolutionary facets of the Helonias group (incl. Helonias, Ypsilandra and Heloniopsis): (1) process of the phylogenetic differentiation, (2) trends in the floral evolution, and (3) historical aspect of the geographical distribution. As regards (1), a phylogram of this plant group is presented based chiefly on the morphological data. Both Helonias and Ypsilandra are paraphyletic, while Heloniopsis is monophyletic. Heloniopsis is divided tentatively into two subgroups, HP-1 and HP-2. In this paper HP-1 is suggested to paraphyletic, while HP-2 monophyletic. The phylogenetic evolution is be presumed to have proceeded in the following sequence; Helonias → Ypsilandra → HP-1 → HP-2. Concerning (2), there exists a trend toward the development of some specific structures that appear to be suited for pollination by insects foraging for nectar. There is also another remarkable trend toward the development of the elongate style. As for (3), the most primitive genus, Helonias, is distributed in North America, while the two descendant genera (Ypsilandra and Heloniopsis) are distributed in Asia. Considering the evolutionary sequence shown above, it seems likely that in Asia the range of the Helonias group has extended from west to east and then to northeast, as the phylogenetic evolution proceeded.

Seven flavonol and eleven flavone glycosides were isolated from the leaves of Aucuba japonica including var. borealis and Helwingia japonica including subsp. liukiuensis, respectively. They were identified or partially characterized as quercetin 3,7-di-O-glucoside, quercetin 3-O-sambubioside, quercetin 7-O-glucoside, quercetin 3-O-xyloside-7-O-glucoside, quercetin 3-O-xyloside-7-O-xylosylglucoside, kaempferol 3-O-xylosylglucoside, kaempferol 3-O-xyloside-7-O-glucoside (from Aucuba japonica), apigenin 7-O-glucoside, apigenin 7-O-diglucoside, apigenin 7-O-neohesperidoside, apigenin 7-O-xylosylglucoside, luteolin 7-O-glucoside, luteolin 7-O-diglucoside, luteolin 7-O-neohesperidoside, luteolin 7-O-xylosylglucoside, 6,8-di-C-glycosylapigenin, 6,8-di-C-glycosylluteolin and vitexin (from Helwingia japonica) by PC, FAB-MS, ¹H- and ¹³H-NMR etc. The flavonoid characters were chemotaxonomically compared among Aucuba, Helwingia and Cornus. As the results, it was shown that Helwingia keeps aloof from Cornus and Aucuba.

Phyllodium elegans (Lour.) Desv. var. javanicum Schindl. was regarded as identical with var. elegans, but is recognized as a distinct variety. It was described from Java and Madura, but is found also in Thailand. A key to both varieties and a related species, and a distribution map of both variety are prepared.

Frequency and morphological characters of the natural hybrid between Taraxacum platycarpum and T. laevigatum were examined in Aichi Prefecture, central Honshu, Japan. In contrast with the case of "T. officinale" reported in the previous paper, only a little parts of "T. laevigatum" had allele b or c of GOT common to T. paltycarpum. The plants having allele b or c were morphologically intermediate between T. platycarpum and pure T. laevigatum in the number of marginal hairs in outer involucral bract, the length of corniculate appendage on the apex of outer involucral bract and the size of achene, and were supposed to be the hybrid between the two species.