|Habitat||Betula nana tundra|
Cross-section round. Outline smooth. Culm center hollow. No visual difference between epidermis cells and sclerenchyma cells. Continuous peripheral sclerenchymatic belt. Large vascular bundles in one row. Small vascular bundles integrated in the sclerench
Outline wavy. Upper and lower epidermis cells of equal size and shape. Vascular bundles centered between the upper and lower side of the leaf. Girders extending from the vascular bundle to both sides of the leaf.