Black Elderberry 100 Seeds The oppositely arranged leaves are pinnate with 5-9 leaflets (rarely 3 or 11). Each leaf is 5-30 cm (2.0-11.8 in) long, and the leaflets have serrated margins. They bear large clusters of small white or cream-colored flowers in late spring; these are followed by clusters of small black, blue-black, or red berries (rarely yellow or white). Seeds need to be stratified.