Baluster

Baluster

Balusters are vertical vase-like pieces used to support a toprail. A series of balusters is called balustrade. The name baluster originates from the Italian word "balaustro", meaning "pomegranate trees' flower buds" (1) because balusters have very similar shapes to such buds.
Although commonly observed in classical-styled buildings, balusters did not appear in either Greek or Roman architecture (3) because ancient Roman buildings are recorded to commonly use lattices motifs with crisscross panels rather than vase-like railings; one of the earliest examples of balusters are of the Tempietto, constructed in 1502 (1). Later Palladio used this as a reference in his famous work. Today, a baluster is considered a feature of early Renaissance architecture.
There are two common types of balusters: single baluster and single baluster and double (or symmetrical) baluster. A single baluster consists of only one belly in a vase form. A double baluster is vertical symmetric with two shapes of vases stacked vertically opposite one another.

References:
(1) Classicist.org (10 April 2022).
(2) Buffaloah.com (10 April 2022).
(3) Wikipedia (10 April 2022).

Le Nguyen Diem Ha