To establish a test guideline (TG) for new cultivar development and to provide baseline data for the varietal evaluation of C. decapetala var. japonica (S. et Z.) Qhashi., which is recognized as a valuable ornamental tree and medicinal plant resource,...
To establish a test guideline (TG) for new cultivar development and to provide baseline data for the varietal evaluation of C. decapetala var. japonica (S. et Z.) Qhashi., which is recognized as a valuable ornamental tree and medicinal plant resource, the habitat conditions and morphological traits of six selected populations were investigated and analyzed. The results are summarized as follows. The survey of habitat conditions for the selected populations of C. decapetala var. japonica (S. et Z.) Qhashi. indicated that temperature ranged from 18.3°C in the Jeju Hankyong group to 22.2°C in the Yeosu group (mean 21.1°C); daily sunlight ranged from 11.4 hours in the Yeosu group to 13.9 hours in the Jeju Hankyong group (mean 13 hours); soil types varied among populations, with clay loam soil in the Yeosu group and sand loam soil in the Wando, Geoje, Gujwa, and Hankyung groups, silt loam soil in the Buan group; and soil pH ranged from 5.3 to 5.7 (mean 5.5), similar to the average pH of forest soils in Korea (5.48) (Jeong Jin-hyeon et al., 2002). The survey of habitat and vegetation types revealed that C. decapetala var. japonica (S. et Z.) Qhashi. was found growing from the tree layer to the low-tree layer and shrub layer in deciduous broadleaf forests and mixed forests with medium to high light intensity and dry conditions at an altitude of 12–180 m, but the population density was very low, and the species was absent in the herbaceous layer. In particular, the Buan, Wando, and Geoje groups have been largely affected by human-induced disturbances, with only a few individuals remaining, suggesting a need for conservation efforts.The selected populations exhibited the following morphological traits: Trees upright, spreading, vine wood, 0.8∼8.0m tall. Stem bark dark brown, grey, grey brown, rough and has bumps, smooth and has bumps, smooth; 1st year branch grey green, green blue, orange brown, glabrous or pubescent. 2nd year branch green blue, dark green, orange brown, glabrous or pubescent. Leaves inter growth. even∼bipinnate leaf, Petiole 2.8∼9.2cm long, grey green, light green blue, grey brown, glabrous or pubescent. Petiolule 0.5∼2.0cm long, yellow green, green brown. Pinna 3.0∼15.0cm long, YG 146C, RP 64A. Leaf lobule 12∼22, 1.2∼3.0cm long, 0.5∼1.9cm width, grey green, light green, glabrous or pubescent. Leaf leaflet, blade obovate, oblong obovate, oblong. Base round, acute, margin entire, apex round. Inflorescences racemiform, cone, columnar, drum, 2∼10, racemiform, 12∼49cm long. Peduncle 1∼75mm long, green grey, yellow green, glabrous or pubescent. Pedicel 2.1∼4cm long, brown green, light green, glabrous or pubescent. Flowers 10∼58 flowers, 1.2∼2.2cm long, 1.7∼3.5cm width. Calyx lobe 3.73∼6.3cm width, YG N144C, light green. Petal 4∼5, 7.6∼15.97mm long, 7.4∼14.04mm width. Petal vexil 7.5∼11.49mm long, 5.2∼13.12mm width. Petal vexil pattern 1.7∼26mm long, dark color, neutral color, light color. Petal keel 4.73∼8.2mm long, 2.8∼4.8mm width. Stamens 8∼11, 0.7∼12mm long, RP 61B, glabrous or pubescent. Stamens anther 2.01∼4.1mm long, PR 63A, GO 165C. Pistil one, 0.7∼1.5mm long, YG 151C, GR 179B. Style stigma GR 179B, grey blue. Legume ellipsoid or oblong, 1∼8, 5.9∼13.6mm long, 2.1∼3.4mm diameter, B 200B, GO 177A, glabrous or pubescent. Seeds 3∼9, globose or ellipsoid, 0.24∼13mm long, 5.44∼9.41mm diameter, 0.12∼2.06g weight, GP N186B, B 200B, shine glabrous or pubescent