Knud Ib Christensen

Revision of Crataegus Sect. Crataegus and Nothosect. Crataeguineae (Rosaceae-Maloideae) in the Old World

Knud Ib Christensen · Systematic Botany Monographs · 1992 · 160 citations

Evidence for genetic association between East Asian and western North American Crataegus L. (Rosaceae) and rapid divergence of the eastern North American lineages based on multiple DNA sequences

Eugenia Lo, Saša Stefanović, Knud Ib Christensen et al. · Molecular Phylogenetics and Evolution · 2009 · 69 citations

Biology, Genetic Diversity, East Asian +13

A morphometric analysis of spontaneous and artificial hybrids of Pinus mugo ×sylvestris (Pinaceae)

Knud Ib Christensen, Ghulam Hassan Dar · Nordic Journal of Botany · 1997 · 43 citations · Full text

Botany, Genetics, Weighted Characters +19

A morphometric study of the <i>Pinus mugo</i> Turra complex and its natural hybridization with <i>P. sylvestris</i> L. (Pinaceae)

Knud Ib Christensen · Feddes Repertorium · 1987 · 34 citations

Botany, Genetics, Reciprocal Introgressive Hybridization +21

Farjon, A. 1998. World Checklist and Bibliography of Conifers

Knud Ib Christensen · Nordic Journal of Botany · 1999 · 32 citations

World Checklist, Natural Resource Management, Vegetation History +1