Ribes fujisanense (Grossulariaceae): A New Obligate Epiphytic Species of Gooseberry Discovered in Central Japan

Abstract

Ribes fujisanense S. Sakag. & Mit. Oishi (Grossulariaceae), an obligate epiphytic gooseberry, is de- scribed here for the first time. It is narrowly endemic in the cool-temperate forests of Mt. Fuji and adja- cent areas of central Japan. Ribes fujisanense is morphologically most similar to R. ambiguum Maxim., but is distinguished by the reddish apex of the calyx lobes, branchlets armed with prickles, petioles with long glandular trichomes and more deeply lobed leaf blades. Phylogenetic analysis based on genome- wide markers showed that the two species are considerably divergent, even though R. fujisanense fully overlaps the distribution of the wide-ranging R. ambiguum, indicating that they are biologically isolated species.