A very rare type of hybrid formed between plants of two different genera. It is indicated by the symbol × before the genus name. For example, the Leyland cypress, × Cupressocyparis leylandii, is a cross between Cupressus macrocarpa and Chamaecyparis nootkatensis.

Taylor's Dictionary for Gardeners, by Frances Tenenbaum. Copyright © 1997 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.