Template:Italic title Template:Taxobox Template:Commonscat Template:Wikispecies Melampyrum nemorosum is an herbaceous flowering plant in the broomrape family, Orobanchaceae. It is native to Europe. In Sweden it is called natt och dag. (Night and Day)<ref name=cabi>Melampyrum nemorosum. Invasive Species Compendium. CABI.</ref> In Russia it is called Ivan-da-Marya. (Ivan and Maria)
This is an annual plant. The new leaves are blue, turning green as they mature. They are usually toothed at the bases.
This plant is a host to the fungus Cronartium flaccidum.<ref name=kai>Kaitera, J. and H. Nuorteva. (2003). Cronartium flaccidum produces uredinia and telia on Melampyrum nemorosum and on Finnish Vincetoxicum hirundinaria. Forest Pathology 33: 205–213. doi: 10.1046/j.1439-0329.2003.00321.x</ref>