I have planted green pole beans successfully before. I planted these green beans in early May. I harvested only 4 normal beans two days ago. But I found that most of the flowers (around 1 cm long) have black and dry petals without stamens and pistils. I pulled out the bud (or seed) and took a closer look as shown in my attachment. Are they normal, or they are infected?
Those look like Scarlet Runner beans, which I've been growing for many years. The first flowers and flower spikes are always sterile, but I haven't looked at them closely to see if they lack stamens and pistils. I wouldn't worry about them unless they've been flowering longer than a few weeks and continue not to produce any usable beans.