A Calyx refers to the protective layer on a flower’s stem that encloses the petals and wraps the bud. Just like its namesake, the Calyx – as in, the new horticultural display at Sydney’s Royal Botanic Gardens – provides an architectural frame that both safeguards and showcases the displays within.

Designed by PTW Architects and McGregor Coxall landscape architects, the Calyx was installed to coincide with the Royal Botanic Gardens’ two-hundredth birthday celebrations last year. The architectural structure sits on a risen patch of lawn near the harbour. The impact of the structure’s striking geometry when approached through the landscape is enhanced by its extrinsic colour scheme: crisp white against crisp green.


The theatricality of the Calyx’s presence is a perfect fit for its form. Sharp, straight steel columns describe the circular circumference of the structure, abruptly changing from vertical to horizontal planes at the top where they fold in towards one another. Seen from above, it is like looking into a camera lens. Seen from within, it is like looking out of one.


The articulated thinness of the steel columns lends the structure an impression of fragility. Of course, this is all a façade, but the visual effect is a nice contrast with the dense organic plant forms that fill and frame the pavilion.



Although the façade represents the first and most important impression of any example of architecture, sometimes it is almost beside the point. In a setting such as the Royal Botanic Gardens, too much façade is a real issue; within this environment, the mission of Calyx almost becomes to undermine itself entirely. More air than material, the architecture successfully cedes its identity to the surrounding elements. As the sun moves through the sky and throws steel shadows in different directions, so too does the visitor’s experience of the pavilion change. This malleability is also what makes Calyx the ideal gallery for the gardens’ ever-changing roster of exhibitions.