Giboshi (ornamental railing top, and flower name) (擬宝珠)

A giboshi or giboshu is: 1) an ornament that is attached to balustrades of bridges, temples or shrines and whose shape resembles that of item 2.
(Described later)

2) The flowers of a leek.
The stem of a leek

3) A herbaceous perennial of the lily family. It is because the bud resembles that shown in item 1. Referring to "Giboshi."

A giboshi is a traditional ornamental feature, which decorates the top of posts or balustrades (handrails, banisters) of bridges, shrines or temples. It is also called "sodai"(leek-shaped post) because it resembles the flowers of a leek.

Giboshi are attached to newel posts (major posts placed at both ends of a balustrade and at constant intervals), and such posts are called "hojubashira" (literally, post of a sacred ball-shaped gem). When a newel post is made of a piece of wood, the giboshi is most often made of a metal, such as brass or bronze, in order to make the wood less susceptible to damage such as due to rain water. When a newel post is made of stone, its giboshi is sometimes made of stone as well. There are rare cases where only wood is used. Giboshi made of tiles in ancient times earlier than the wood ones have also been found.

This is not to be confused with the decoration attached to the top of a Buddhist pagoda, such as a five-storied pagoda or gorinto (a gravestone composed of five pieces piled up one upon another). This is not a giboshi but a hoju (sacred ball-shape gem).

Origin

There are many theories concerning the origin of giboshi, and one of them suggests that it comes from hoju in Buddhism. It is said that the shape of a hoju represents those of urns for Buddha bones or that a hoju is the beautiful ball-shaped gem that was said to have come out of a dragon god, and that a hoju is placed on a palm of Buddhist statues, for example those of Jizo Bosatsu (Jizo Bodhisattva).

One theory is that it was named giboshi (literally, imitated hoju) because it was made in imitation of hoju.

According to another theory, the foul odour characteristic of leeks was believed to ward off evil spirits and the hoju shape came to be used to get help from the power they held. Based on this theory, it is said that the characters of 擬宝珠 (giboshi) were later used to replace the original 葱帽子 or 葱坊主 pronouced as giboshi and indicating the head of a leek. This theory can also explain the fact that giboshi are used in non-Buddhist builldings, such as bridges and shrines.

History
In shrines, the five-color hoju-shaped ornaments in the main building of Ise-jingu Shrine constitute their original shape. It appears that giboshi were initially used only in buildings related to the imperial court.

Ancient examples of decorations resembling giboshi can be found in picture-etched stones from the age of the Han dynasty in China and wall pictures in Dunhuang City. Within Japan, giboshi using tiles, which are said to have been utilized for Nijo Ohashi Bridge, have been found in the site of the former Heijo-kyo Capital.

Incriptions relating to the origin of giboshi are sometimes present on those used in bridges. Of the existing giboshi with an inscription, the one that remains partially in Sanjo Ohashi Bridge in Kyoto is the oldest. It is said that the giboshi was made when the bridge was rebuilt in the Tensho era (1573 - 1585) according to an order of Hideyoshi TOYOTOMI. Gojo Ohashi Bridge was also constructed in the same era, and it is said that the giboshi of the bridge were the first ones used in bridges (however, the present giboshi of the bridge are not the original ones). In addition, the giboshi of the upper bridge and of the lower bridge in Morioka City in the early Edo Period were made in imitation of the ones described above.

Shapes of giboshi and the name of each part

The hoju-like part at the top alone is sometimes called "giboshi." The part looking like a bowl with its open side down is called a "fukubachi" (a rounded base), and the part connecting them a "kakikubi" (neck-like part under a bulbous-topped post, giboshi). The cylindrical part under the fukubachi is called "do" (a cylindrical column).

The shapes of giboshi have changed according to the age, and as an example, giboshi whose hoju part is relatively small, with a diameter larger than the height, is called "Kamakura type." The size of the hoju part has mostly become larger over time.