Activated charcoal and graphite for the micropropagation of Cattleya bicolor Lindl. and a orchid double-hybrid ‘BLC Pastoral Innocence’ - doi: 10.4025/actasciagron.v34i2.12257. Acta Sci. Agron. 2011;34(2):157-161. doi:10.4025/actasciagron.v34i2.12257