Contribution to the biosystematics of the wild Vaccinium species distributed in Turkey

The genus Vaccinium L. (Ericaceae) consists of shrubs or dwarf shrubs species widely distributed in Southeast Asia, America, and Europe. In the present paper, members of the genus (V. arctostaphylos, V. myrtillus, V. uliginosum, V. vitis-idaea) naturally grown in Northeast Anatolia were compared in terms of leaf venation, seed micromorphology, and palynological properties based on 16 populations in detail. Present findings revealed that number of areoles (the small area bounded by secondary veinlet) is 8–9 for V. arctostaphylos, 5–7 for V. myrtillus, 3–4 for V. uliginosum and V. vitis-idaea. Scanning electron microscope observation shows that the leaf adaxial surface is fiber-fluted in V. arctostaphylos, ruminate in V. myrtillus, V. uliginosum, and V. vitis-idaea due to epicuticular waxes. In addition, the seed shape of V. arctostaphylos in outline varies from triangular, tetragonal to oval, whereas they are lunate to reniform or falcate in the rest of the examined taxa. Epidermal cells of the seed are quadrilateral with straight anticlinal walls in V. arctostaphylos, however, they are most elongate rectangle with weakly undulate anticlinal walls in the rest species. The mean tetrad diameter (D) of pollen belonging to all examined species is 29.89 (21.47–43.22) μm while the lowest mean D was found in V. uliginosum (24.59 μm) and the highest mean D was found in V. arctostaphylos (36.74 μm). Principal component analysis based on 47 traits (flower: 9, leaf: 18, seed and fruit: 9 and pollen: 11) showed that the leaf length and width, teeth numbers, tetrad diameter, equatorial axis, and polar axis were the most valuable characters to distinguish the examined taxa in the present paper.