This is an important feature for chemical control in late fall and winter. Himalaya blackberry has showy flowers that form in large clusters at the end of shoots. Each flower is about 1 inch across with five white or pink petals. The fruits are black and tasty when ripe. New plants start from crown regrowth, rhizomes, and seeds that germinate in fall and spring.
Reproduction is similar for the other three species.
The scrambling habit of Himalaya and the other vining wild blackberries smothers existing plant growth. In addition, the tangled mass of thorny stems blocks access of humans, livestock, equipment, and vehicles to pastures and waterways. In forest areas, timber logging operations create large open areas that are often invaded by wild blackberries. When grazed, the thorny stems can injure the nasal passages of livestock. Another undesirable aspect of vining blackberry plants is that they are a good source of food and shelter for rats.