Torch Ginger (Etlingera elatior) matches in some aspects the plant on fol. 38r of the Voynich manuscript - with the flowers in the base of the plant with the palm-like leaves above. The torch ginger is east Asian flower and is somewhat unlikely to be starring in 15th century European (as I believe) manuscript so I am adding it to my list reluctantly.
It is possible that the VMs artist used the defect in the parchment to imply flames and the whole composition is torch-like. Also there is a dot inside each 'drop' which reminds of the Yin/Yang symbol - I saw few people suggesting this on the net, I apologize, I couldn't figure out who came up with the Yin/Yand association first.
The VMs drawing has some resemblance with the Juniper picture in The Tudor Pattern Book (MS Ashmole 1504), but Juniperus id does not explain the flowers at the base of the plant.