The arums are, as I know them, summer dormant winter growing plants notable for lush foliage and foul-smelling "flowers". Most of the members of this genus produce foliage in the autumn; in our climate this foliage sometimes persists through the winter but is more often than not destroyed. I tried this species years ago in the open garden, and it lasted about three years before it finally gave up. Four years ago a tiny offset appeared at one of the local plant exchanges and I decided to give it a try again. This time it was planted in the protected cold frame. It's blooming this year for the first time.
Arum dioscoridis is notable for the color pattern of the interior of its spathe. Something nicked this one just as the spathe was unfurling, and so the spathe is not quite as striking as it might have been. But you can easily get the idea from what's there.
This one produces a pervasive, reeking, stealth stench: I could smell it from inside the house (there was an open window near the plant).