Acer (maple) species and their horticultural varieties are world-famous ornamental trees with colored leaves that are widely used in natural and potted landscaping, as well as gardening (Lin et al., 2015). Japan and the United States breed the most maple varieties, which are hybridized or selected from A. palmatum, A. saccharum, A. rubrum, A. japonicum, A. shirasawanum, A. buergerianum, and A. morifolium (Gao et al., 2015). In recent years, China has become more involved in the cultivation of maple varieties (Zhu et al., 2018). According to the National Forestry and Grassland Administration, nearly 50 new Acer cultivars have been certified in recent years. After more than 10 years of continuous work, more than 30 horticultural cultivars with specific fruit shapes, leaf colors, and branches from A. elegantulum, A. palmatum, and A. pubipalmatum have been bred at Ningbo City College of Vocational Technology, and 10 have been registered as new cultivars by the National Forestry and Grassland Administration. In particular, ‘Fendai’, ‘Simmeiwu’, and ‘Caizhe’ stand out with a bright, unique leaf color and have greater ornamental potential than the origin species of A. elegantulum.
Acer elegantulum is a deciduous tree distributed in East Asia (Xu et al., 2008). Trees are up to 15 m tall. Foliage is thick and papery, with short hairs on the middle vein. Mature leaves are 5 to 13 cm long and 7 to 16 cm wide, with a base that is truncate or broadly cordate. The leaf apex is acuminate and serrated. Leaves have 5 or 7 lobes located deep to one-half to three-fourths the leaf length, and the petiole is 2.8 to 6 cm long. Inflorescences are paniculate and terminal on a two-leaf branchlet (Lin et al., 2017). The formula is K5/C5A8 (Xu, 1998): five sepals that are ovate to oblong and ≈2 mm, five petals that are obovate and ≈2 mm, and eight stamen that are Samara glabrous and ≈6 × 5 mm with obtusely spreading wings. The ornamental value of A. elegantulum is not as high as A. palmatum, so this species is often used as the grafting stock of A. palmatum varieties, such as A. palmatum ‘Dissectum’, A. palmatum ‘Atropurpureum’, and A. palmatum ‘Aureum’. This is an effective way to improve the ornamental value and economic benefits of A. elegantulum.
Lin, L.J., Lin, L. & Zhu, Z.Y. 2015 ISSR analysis of the genetic relationships among 25 Acer plants germplasm resources Guihaia 35 1 9 14
Lin, L., Lin, L.J., Zhu, Z.Y., Ding, Y.L. & Kuai, B.K. 2017 Study on the taxonomy and molecular phylogeny of Acer in China Acta Hort. Sin. 44 8 1535 1547