This species is discussed under R. degronianum, page 646. It is figured in Bot. Mag., n.s., t.771, from a plant at Wakehurst Place, Sussex raised from Doleshy's seed-number 10 and presented to the garden by the late Geoffrey Gorer in 1970.
subsp. makinoi (Tagg) Chamberlain R. makinoi Tagg – See R. degronianum f. angustifolium, page 645.