| Betula pendula var. lapponica (Lindq.) Hämet-Ahti | |
| Publ. & Syn. | Hämet-Ahti, Mem. Soc. Fauna Fl. Fenn. 65, 1: 9 (1989). - Betula verrucosa Ehrh. var. lapponica Lindq., Svensk Bot. Tidskr. 41: 62 (1947). Described from northern Europe and western Siberia: "Habitat in Suecia, Norvegia et Fennia septentrionalis, versimiliter in Russia septentrionalis et Siberia occidentalis". No type indicated but an illustrated specimen (Sweden: Lappland, Kengis, 1856, leg. L.L. Laestadius, S) would be a suitable lectotype. |
| Notes | Shemberg (1992) mapped Betula pendula at the arctic boundary along the lower Ob River in northwestern Siberia. Lindquist (1947) described a northeastern Fennoscandian race, var. lapponica, separable from the more southern var. verrucosa (= var. pendula) in 6-7 characters. However, the majority of these characters concern bark, branching pattern, and floral scale and fruit characters not usually available in herbarium specimens, and a revision of existing material is very difficult. The variety seems to be the exclusive race in the northern and northeastern parts of the range of the species. Hämet-Ahti et al. (1998) accepted it but Jonsell (2003c) only discussed it. We consider it a recognizable race. |
| Chromosomes | (1) 28 (2x). - Europe. - Numerous reports. (2) 42 (3x). - Europe (Fennoscandia). - Jonsell (2000c, secondary report from three provinces). All chromosome count reports from Fennoscandia refer to the southern var. pendula (Jonsell 2000c). The triploids recorded from Scandinavia may be due to hybridization between diploid B. pendula and tetraploid B. pubescens. Such hybrids are frequent (e.g., Jonsell 2000c; Elven et al. 2005). |
| Geography | European (N) - Asian (W): (SIB). |
| Distribution | N = F E = b YG = b [ key ] |
| Parent taxon | Betula pendula Roth |
| PAF ID | 610201a |