Upon germinating, the tiny seedling must act quick earlier than its meager vitality reserves are exhausted. If fortunate, the rising seedling will come into contact with an oak root and start growing a wierd organ known as the nodule or tubercle. Thus begins its parasitic way of life. The tubercle continues to develop all through the lifetime of the plant, growing into an amorphous, woody blob that continues to envelope an increasing number of oak roots. Its inside the tubercle that all the parasitism takes place.
Cells inside the bearcorn tubercle penetrate into the vascular tissues of the oak root, stealing all of the water and vitamins the plant will ever want. Over time, the bearcorn tubercle coaxes the roots of the oak to fan outward just like the crown of a tiny tree. In doing so, bearcorn is successfully rising the quantity of floor space accessible to make extra parasitic connections. Apparently this all comes at nice value to the oak roots. Over time, oak root measurement inside the tubercle vastly diminishes till some fully perish. Contemplating the dimensions of some bearcorn populations, one might anticipate the oak host to battle again.
Certainly, it might seem that oaks should not helpless in opposition to bearcorn infestations. Examination of the cells inside bearcorn tubercles revealed that because the parasite grows, the oak will start flooding the contaminated cells with tannin-rich compounds. Apparently this serves to sluggish the stream of water and vitamins into the tubercle. There may be even proof that a few of these tannins are transferred into the bearcorn tubercle, main some to counsel that the oak is actually poisoning its bearcorn parasites, albeit slowly.