WOOD ANATOMY OF FOUR DWARF SHRUB SPECIES OF ERICACEAE IN TURKEY: ECOLOGICAL AND PHYLETIC ASPECTS

摘要

Wood anatomical features of 4 dwarf shrub species of Ericaceae in Turkey (Andromeda polifolia L., Bruckenthalia spiculifolia (Salisb.) Reichenb., Epigaea gaultherioides (Boiss. & Ball.) Takht., and Rhodothamnus sessilifolius P.H. Davis) were studied, and wood anatomical characters of the last species were given as a new record. Growth rings vary from indistinct (in upper part of the mountains) to distinct. Vessels are predominantly solitary, and vessel elements are relatively short with scalariform perforation plates having numerous bars, except Bruckenthalia which has simple perforations. Lateral wall pitting of vessels, both intervascular and between vessels and rays, is scalariform to opposite in Rhodothamnus Reich, and Epigaea L., opposite to alternate in Andromeda L., and alternate in Bruckenthalia Reichb. Helical thickenings are not observed in vessel walls of any of these species. Imperforate tracheary elements are fibre-tracheids with fully bordered pits in the radial and tangential walls. Axial parenchyma is abundantly paratracheal (scanty paratracheal, paratracheal-vasicentric), and sometimes apotracheal-diffuse. Rays are homocellular with a predominance of upright cells. Multiseriate rays are few or absent. The wood anatomy of these species, particularly of Rhodothamnus and Andromeda, shows evidence of adaptation to alpine habitats. The woods of the species exhibit both primitive and evolved wood anatomical characteristics.