Back at the Orchid Show, visitors swooned before the ghostly Miltonidium Fall in Love “White Fairy,” with its magenta heart, nestled in the crooks of trees. Others ducked beneath the scraggly, tentacled roots of an archway of spotted purple and pink Vandas or gazed at their reflections in a dark pool lined by blazing Cymbidium Golden Boy “Nevada.” Some stopped to marvel at a mountain of Oncidiums, Epidendrums, Cattleyas and Phalaenopsis in a sweetly autumnal palette, perched on a bamboo grid that echoed the conservatory’s glassy panes.

If the line between nature’s magnificence and human intervention was blurred, that was how Daniël Ost, the Belgian floral designer who curated this year’s show, intended it.

“I didn’t want to see this exhibition as a wedding or a party, where you put 100 or 2,000 or 10,000 Phalaenopsis together, which I already did in my life,” he said in a telephone interview from his home in Sint-Niklaas, Belgium. “I thought it should remain a botanical garden and show the collection they had.”