baluster
noun
[ ˈbaləstə ]
• a short decorative pillar forming part of a series supporting a rail or coping.
Origin:
early 17th century: from French balustre, from Italian balaustro, from balaust(r)a ‘wild pomegranate flower’ (via Latin from Greek balaustion ), so named because part of the pillar resembles the curving calyx tube of the flower.