Morphologically typical fruit bodies of Coriolus versicolor were consistently produced within 8–12 weeks on short lengths cut from living birch or hazel stems by allowing the latter to be colonized from dikaryotic cultures and placing them, with their bases submerged in water, in closed horticultural propagators. The fruit bodies expanded at a radial rate of up to 3–5 mm per day for 4–5 days before slowing down, reaching maximum size 15–20 days after the onset of rapid primordium development. Environmental factors, particularly light, markedly affected the degree of pigmentation and zonation of the fruit bodies. C. versicolor fruit bodies also developed readily in the field on inoculated birch logs placed on swampy ground, and on freshly exposed cut surfaces of decaying stumps. The developmental characteristics of such fruit bodies were similar to those of artificially propagated ones.