Radial Variation of Rays in two Commercial Softwoods Grown in Korea

Radial variation of the height and number of uniseriate and fusiform rays within the stems of two typical Korean softwoods, Pinus koraiensis and Larix kaempferi , was studied. The average height of uniseriate rays was about six cells in Pinus koraiensis and nine cells in Larix kaempferi. The height of fusiform rays, including radial resin canals, was on average 20 cells in both species. The height of fusiform rays was greater than that of uniseriate rays: about 3.2 times for Pinus koraiensis and about 2.3 for Larix kaempferi. The height of uniseriate and fusiform rays was lowest near the pith and increased with age to about ring 10 - 20 and then became constant toward the bark. The number of uniseriate rays in a 0.5 × 0.5 mm area was about 6.5 for Pinus koraiensis and 9.5 for Larix kaempferi. The number of uniseriate rays was at a maximum near the pith and decreased to about ring 10 - 20 and was nearly constant for subsequent rings. The ratio of fusiform to uniseriate rays was 1:45 in Pinus koraiensis and 1:53 in Larix kaempferi. Consequently, it was considered that the results obtained might provide useful information for evaluating juvenile and adult wood as well as identifying both species.