Nothing on fol. 18v of the Voynich Manuscript screams 'Edelweiss!', but then the only thing that screams 'Edelweiss!' in the 10th century Pseudo-Apuleius French manuscript in the National Library of Netherlands here is the written author's intention. Edelweiss or Leontopodium (Lion's Paw) is also hard to recognize in the 13-14th century Italian manuscript (Egerton 747, British Library here ).
So, can the fol. 18v of the VMs represent Edelweiss? Why not?
Distant real life possibility for this VMs page is the Passion Flower (Passiflora). The earliest known European depiction was the 16th century Van Cleve Madonna until it was proven that the Passion Flower was added to the painting at later date.