There was found a new karyotype in a diploid female clone of Rumex acetosa collected from Matsuyama city. The 12 autosomes (Fig. 1., I-XII) but two X-chromosomes were classified into five main groups. One consists of a large secondary-constricted chromosome (Ibid. III) by which the new karyotype is readily distinguishable from any other karyotype noted formerly. At prophase (Fig. 3), the outer segment adjacent to the secondary constriction (Ibid. III) is very darkly stained in contrast to the inner segment which is just as light as the short arm of ordinary subterminal-typed chromosome. Another group includes one small median-typed (Fig. 1, XI) and one small submedian-typed chromosome (Ibid. XII). At prophase, the former (Fig. 3, XI) has an outer region stained darkly in one arm, and such a dark region is lacking in the latter (Ibid. XII). It is probable that, as shown in Fig. 4, the secondary-constricted chromosome (Fig. 4, A) has arisen after the short arm of ordinary subterminal-typed chromosome (Ibid. B) had accepted the outer region stained darkly from one (Ibid. C) of two small median-typed chromosomes. The secondary constriction has not yet developed into a nucleolus organizer.
Annual growth cycle and seasonal changes of carbohydrate reserves in various organs were studied with populations of Pteridophyllum racemosum, an evergreen perennial herb of Papaveraceae, grown as an undergrowth of the subalpine Abies forest (2, 250m in altitude) of northern Yatsugatake Mountains, central Japan. The plants unfolded late in May, soon after snow melting. The growth of new organs in dry weight was inclined to leaves and flower stalks in early growing season and to roots in late summer and autumn. The annual growth of new organs of the population reached 51.5g d. w./m2. Seasonal changes of sugar, starch and hemicellulose contents in leaves, roots and rhizomes were pursued. Carbohydrate reserves in the old organs decreased in the early growing season till the end of June, corresponding to the period of rapid development of new leaves and flower stalks. The old leaves as well as roots and rhizomes exported considerable amount of reserves in this period showing that they played in winter a role as the reserve organ. Reserves were filled again in overwintering old organs till the end of the growing season. By combining monthly dry weight increments in new organs and the consumption or accumulation of reserves in old organs, monthly and annual net production of the population were calculated. The latter was 40.5g/m2•yr which corresponded to 3.6% of the annual net production of the canopy Abies trees. During the initial two and a half months of the growing season, till the end of July, the plant produced 72% of the annual net production.
Seedlings were examined in 13 species of Pittosporum with special reference to the number of the cotyledon and to the vascular supply for the cotyledon. Those species may be divided into three groups (Table 1) in respect of the cotyledonary features. Group I includes the species in which dicotyly seems to be stable; Group II, the species in which seedlings show sometimes syncotyly and monocotyly although normal ones are dicotyledonous; and Group III includes the species in which polycotyly is quite normal, dicotyly being never found. The roots of all the species are usually tetrarch, and in the transition region each metaxylem and phloem are respectively divided laterally into two, the original protoxylem pole of the root being nearly unchanged in its position. Thus eight collateral bundles are formed in the hypocotyl axis (Fig. 1) Each cotyledon is supplied with one pair of these buddies together with one protoxylem pole of the root, as its median strand of the double bundle nature. As a consequence, all primary vascular strands in the hypocotyl are supplied for the cotyledons in the case of the seedlings with four cotyledons. In the seedlings with one or two cotyledons, hypocotylar bundles except those supplied for the cotyledon die out below the cotyledonary node. Seedlings with three or five cotyledons have the root with triarch or pentarch xylem respectively. The pattern of the vascular behaviour in the seedling gives no evidence of the fact that the monocotyly and tetracotyly in Pittosporum have resulted respectively from the fusion and bifurcation of the original two cotyledons.