Dracunculus Vulgaris (Dragon Arum) is not a perfect match for the Voynich manuscript (Beinecke 408) fol.28r, but is my favorite placeholder ID for that drawing, mostly because of Arum's unique leaves formation and the 'hidden dragon' formed by its male and female flowers.
UPDATE. I found couple of representations of the plant from 10th century. The first one is Pseudo Hippocrates (BnF Latin 6862 here). The second is Pseudo Apuleius (The Hague, RMMW, 10D7 here).