Guaiacum From Santalum Album. Guaiacum consists mostly of wavy interwoven wood-fibres, numerous 1-rowed medullary rays, large single ducts and narrow lines of wood, parenchyma in 1-2 rows of irregular and interrupted circles - all cells contain resin; santalum album has ducts single, moderate size, wood-parenchyma narrow, contains volatile oil or calcium oxalate, medullary rays narrow, in 1-2 rows. See pages 167, 334.
Santalum Rubrum From Haematoxylon. Santalum rubrum has large ducts, 1-rowed medullary rays, wood-parenchyma 4-rowed in interrupted, irregular circles, cells with red resinous coloring matter, parenchyma with calcium oxalate crystals; haematoxylon has large ducts, often in groups of 2, medullary rays 2-rowed, wood-parenchyma in broad, wavy, circular lines, coloring matter in wood-fibres and ducts. See pages 294, 308.