My first association for fol. 18r of the Voynich manuscript (Beinecke 408) was Calendula. The overall impression I get is so strong that at this time I will go with it despite the fact that I like Edith Sherwood's proposal for Aster alpinus very much. Ethel Voynich was not able to decide between the Aster and the Calendula. O'Neill proposed Ringelblume, which is German for Calendula. Petersen went with Calendula officinalis. The leaves, the buds, the flower shape is so realistically drawn that I will go with Calendula. The coloring of every other petal in blue most likely has something to do with the text code. The same pattern is common all over the manuscript. Aster Alpinus, however, is a valid proposal - with its blueish-purple flowers and many people may like it better than Calendula.