Cornus kousa 'Rutpink' SCARLET FIRE® Japanese dogwood

Cornus

Cornus is a genus that botanists rightly regard as true aristocracy among woody plants. It comprises approximately 50–60 species of trees and shrubs distributed mainly across the temperate regions of the Northern Hemisphere, with centres of diversity in East Asia and North America. Fossil records confirm its presence as early as the Tertiary period, and the first scientific description of the genus was published by Carl Linnaeus (1707–1778) in 1753 in his Species Plantarum. For centuries, dogwoods have accompanied human culture not only as ornamental plants, but also as sources of exceptionally hard timber, medicinal substances and symbolic meaning in folk traditions, where they often represent strength, order and longevity.

Japanese dogwood (Cornus kousa) originates from East Asia, where it occurs naturally in Japan, Korea, and parts of China. It was scientifically described in the 19th century based on Asian plant material examined by Henry Fletcher Hance (1827–1886), who published it under the name Cornus kousa. The species was introduced into European and North American botanical collections, and later into nursery production, during the wave of botanical exploration and plant exchange at the turn of the 19th and 20th centuries. It was valued primarily for its pronounced seasonal interest, offering ornamental appeal from spring through autumn, and for its edible fruits. Japanese and Chinese botanists studied its variability in the wild and, in the past, described local forms that were treated as two subspecies, ssp. kousa and ssp. chinensis. While some authors regarded ssp. chinensis as a more vigorous, loosely flowering form with larger inflorescences and considered it worthy of formal recognition, modern taxonomy generally prefers to treat the species simply as Cornus kousa, without further infraspecific distinction.

After the invasion of the lethal anthracnose disease into the United States in the 1970s, dogwood breeders began focusing on hybridization aimed at developing cultivars that would not only be resistant to this disease but would also retain the rich flower colors characteristic of the native American flowering dogwood, Cornus florida, a goal that for many years seemed unattainable. In Japan, pink flowering dogwoods had already been available since around 1970, such as Satomi and Benifuji, but in the United States the first real breakthrough came in 1988, when after many attempts at interspecific hybridization between Cornus kousa and Cornus florida, Dr. Elwin Orton of Rutgers University in New Jersey introduced the cultivar Stellar Pink®, featuring pale pink bracts. His tireless work of planting and evaluating approximately 1,500 new plants each year was supported by one of his students, the enthusiastic young botanist Thomas Molnar, who continued the breeding program at the university’s test fields in New Brunswick after Orton’s retirement in 2008. During a spring visit in 2012, Molnar discovered a single shrub in full bloom whose color left him speechless. At last, what both breeders had long sought and what had taken 45 years of breeding effort was achieved: a Japanese dogwood bred in America with large pink flowers. Plant patent PP28311 was granted in 2015, and the first plants have been commercially available since 2017 under the trade name SCARLET FIRE®.