Die Markfleckigkeit des Coigue-Holzes [Nothofagus dombeyi (Mirb.) Oerst.]

A Comparative Account of the Pith Flecks ofAnnona squamosaLinn. andWalsura piscidiaRoxb.

“…Unfilled or partially filled mines, noticed in Annona squamosa, were also recorded in Nothofagus dornbeyii (Knigge and Bonnemann 1969). In the latter instance, they were formed in the late wood and were fully occluded in the following vegetative period; in Annona, however, they remained unfilled or partially filled.…”

“…In Acer saccharum, Gregory and Wallner (1979) observed no structural abnormality in the wood adjacent to pith flecks, but they attributed this to the non-extension of mining effects to the elements of vascular cambium. Knigge and Bonnemann (1969) and Gregory and Wallner (1979) considered the vascular ray parenchyma or its precursors s the source of all cells that filled the mined tunnel to form flecks. Although, it may be true of the taxa they investigated, in both species studied by us, fleck cells are derived both from ray and axial parenchyma of the differentiating xylem zone; but the contribution from ray is always greater in both species.…”

“…Pith flecks have been reported in plants of at least thirty five families of dicotyledons (Krishnamurthy et al 1986). The structure and development of pith flecks have been known in a few cases (Kulman 1964;Knigge and Bonnemann 1969;Gregory and Wallner 1979;Vasudeva Rao and Krishnamurthy 1980;and Tanaka and Matsuzaki 1983), but still their effect on the structure of adjacent wood area has not been properly documented. Therefore, the present work on the pith flecks of Annona squamosa and Walsura piscidia was undertaken.…”