A new species Cerasus kumanoensis discovered from the Kii Peninsula: promising as an ornamental cherry tree

A new species Cerasus kumanoensis from the southern Kii Peninsula, Japan

Toshio Katsuki

Tama Forest Science Garden, FFPRI, Hachioji, Tokyo, Japan.

Acta Phytotaxonomica et Geobotanica, 69(2):119-126, June 2018, DOI：10.18942/apg.201801( External link )

Nine species of Cerasus are native to Japan; in addition, there are many cultivars, including C. ×yedoensis 'Somei-yoshino' (* 1). We, at the Forestry and Forest Products Research Institute (FFPRI), are pursuing research to reveal the mutations in wildtype species with the goal of reconstructing the Cerasus taxonomic system. However, during an investigation of gene mutations in C. jamasakura, which was conducted by the FFPRI and other entities and published in 2014, some samples from the Kii Peninsula appeared to be different from the existing species. C. jamasakura plants in western Japan have more mutations, and local variants may have emerged in the Kii Peninsula. In addition, Cerasus with a high ornamental value is promising as a new resource. Therefore, we conducted a field survey in the Kii Peninsula and characterized an unknown Cerasus species in detail.

The FFPRI and Wakayama Prefecture Forestry Experiment Station jointly conducted a field survey from 2016 to 2017 and characterized cherry trees distributed in the Kii Peninsula. We found a Cerasus species that was distinct from the native C. jamasakura or C. leveilleana (Fig. 1, 2). It was characterized by short, hairless peduncles (Fig. 3) and narrowly ovate leaves, which were smaller than those of C. jamasakura or C. leveilleana (Fig. 4). In addition, its flowering period was earlier than that of the two native species, with no overlap (Fig. 5). Many wild trees of this unpublished species were found distributed across an area of 90 km from north to south and 60 km from east to west around the Kumano river basin (Fig. 6). Based on these characteristics, we concluded that this is a new species (* 2) and named it Kumano cherry (C. kumanoensis). The scientific name of this species was published in Acta Phytotaxonomica et Geobotanica, a journal of the Japanese Society for Plant Systematics, vol. 69, issue 2, in June 2018. This is the first new Cerasus species discovered in approximately 100 years after C. speciosa, which was published in 1915.

* 2 New species
The FFPRI concluded that C. kumanoensis is a new species. However, the Japanese Society for Plant Systematics has only accepted our paper for publication in its journal because it has no system for certifying new species. New species are widely accepted after being tested and agreed by botanical taxonomists.

 
Figure 1. C. kumanoensis tree Figure 2. Flowers of C. kumanoensis

Figure 3. Inflorescences of C. jamasakura (left), C. kumanoensis (center), and C. leveilleana (right; peduncles are indicated with red circles)

Figure 4. Mature leaves of C. jamasakura (left), C. kumanoensis (center), and C. leveilleana (right; leaf blades are indicated with blue circles)

Figure 5. Flowering periods in 2017 for C. kumanoensis and C. jamasakura (native), C. ×yedoensis 'Somei-yoshino', and C. leveilleana (planted) in Kozagawa-cho, Wakayama prefecture

Figure 6. Estimated distribution area of C. kumanoensis