My 4 year old SHISANDRA rubriflora has produced lots of red flowers for the past two Springs but to my disappointment, I have never had any berries from it. The vine is lush and extremely healthy in a sheltered partly shaded area of my garden. I have been reading that I need a male and female for berries (which was not pointed out to me when I bought it unfortunately), but I'm not sure which sex this vine is. Can anyone help me out?