Lignum is Latin for wood and may refer to: Gmelina lignum-vitreum, plant endemic to New Caledonia; Lignum, common name of Muehlenbeckia florulenta, plant native to inland Australia; Lignum Crucis, remnants of the True Cross; Lignum Ltd, see John C. Kerr; Lignum vitae, trade wood from trees of the genus Guaiacum; Lignumvitae Key, island in the ...