Neglected and forgotten: The fire lilies (Lilium bulbiferum agg.) of the NW European lowlands

Lower Saxony hosts numerous populations of Lilium bulbiferum L., which are grouped into four taxa based on different patterns of vegetative and generative reproduction. The groups are confirmed by quantitative differences in leaf and flower morphology. The taxa occupy the light soils of the old moraine (lowland) landscape and the Harz Mountains. Populations in the landscape and in farm gardens were investigated. In the latter, it was possible to establish differences in pollination biology by controlled pollinations within and between taxa. Based on the very different states of expression of the analyzed traits, four taxa were described: Lowland saffron lilies (L. croceum Chaix), Highland fire lilies (L. bulbiferum L.), and two additional Lowland fire lilies (L. buchenavii Focke ex R. J. Koch and L. buchenavii var. govelinense R. J. Koch). L. bulbiferum s.l. is thus treated here as an aggregate of four distinct taxa (L. bulbiferum agg.).