The Calyx

The Calyx was conceived to celebrate the bicentenary of the Royal Botanic Garden Sydney in 2016. It stands on Gadigal Country, on the site of the former Tropical Centre, whose glass pyramid of 1970–71 was demolished in 2015 to make room for it.

The commission went to PTW Architects through a limited design competition. The practice worked with Cockram Construction, which was also its client on the project, and with landscape architects McGregor Coxall, while BG&E provided structural engineering. Rather than clearing the site, the team kept the curved Arc glasshouse designed for the garden by Ken Woolley of Ancher Mortlock & Woolley. It is dated 1985 in Woolley's project list, 1987 for Architecture AU and 1988 for PTW. As part of the works it was reglazed and refurbished.

Opened in 2016, The Calyx presents itself as an ever-evolving horticultural and event space. Its successive exhibitions, among them 'Sweet Addiction' on the botanic story of chocolate, 'All About Flowers', 'Pollination', 'Plants with Bite' and 'Love your Nature', had drawn more than 280,000 visitors according to the garden. In August 2017 Architecture AU published an extended review of the building by Anthony Burke.

The building occupies a single level, with about 2,000 m² of gross floor area on a site of roughly 1,500 m². Its governing idea is to finish the figure begun by the Arc: a white colonnade, whose radially arrayed columns rise from the circumference of a circular plan and then bend inward to the horizontal, carries the curve of the older glasshouse round into a full circle around a forecourt set on a low stone dais.

In his review, Anthony Burke reads the project less as a building than as an assembly of light, glassy volumes, and likens the colonnade to a kind of camera for the garden, a device that frames its views. The only enclosed space added by the project is a modest curved foyer slipped between the Arc and the colonnade, holding services, the shop and ticketing. The exhibition spaces are designed to be reconfigured from one show to the next, and the pavilion can host up to 200 seated guests or 400 for a cocktail function.

The Calyx has no permanent collection in the traditional sense; instead it stages seasonal and themed horticultural displays, frequently focused on conservation and the environment. Its most striking fixed feature is a living green wall that the garden counts among the largest in the Southern Hemisphere.

The exhibition 'Alchemy of a Rainforest' brings together more than 18,000 tropical and subtropical rainforest plants, including rare and unusual species. It pairs them with installations made from recycled materials: a shimmering, undulating canopy by the company ERTH, sculptures by Jane Gillings crafted from repurposed plastic waste and depicting seeds, flowers, branches, fungi and butterflies, and an oversized satin bowerbird's bower built from upcycled materials.

The Calyx lies in the heart of the Royal Botanic Garden Sydney, close to the Palm Grove and the Australian rainforest planting, with the Domain stretching beyond the garden's southern edge. Its foyer holds the shop, and the Leaf Dept. café, located at The Calyx, offers outdoor seating. Exhibitions change regularly and the pavilion is also hired out for functions, with occasional closures, so the garden's programme is worth checking before setting out. The visit extends easily to the Fernery, the Palace Rose Garden and the harbour foreshore.