The city of Chicago just welcomed a set of enormous twins, and everyone’s waiting for them to stink up the joint.

To put it slightly more politely, the Chicago Botanic Garden (CBG) has moved two ready-to-bloom corpse flowers out from the production greenhouses and into the Semitropical Greenhouse, where they are now on display.

Corpse flowers, of course, are the famously odoriferous celebrity plants that—the past few years especially—have caused greenhouse sensations everywhere from London to New York. Native to the island of Sumatra, they spend much of their lives cycling between dormancy and a leafy period. Once every half-decade or so, though, they go through a flower cycle, during which they grow a human-sized, extremely rank bloom.

Botanic gardens around the world began collecting corpse flowers in the early 2000s as part of an effort to preserve the species, which is under threat from habitat destruction. These two, named Java and Sumatra, came from the same parent plant, which was propagated at the University of California, Berkeley, but they’re easily distinguished. Java is tall and lean—nearly 52 inches tall and 34 inches wide, reports DNAInfo—while Sumatra is squat and powerful, at 45 inches tall and 40 inches wide.

“This is one of a few times that two corpse flowers in their bloom cycles have gone on public display at the same time,” the CBG writes in their official and very informative Corpse Flower FAQ. The CBG has a lot riding on the twins. Back in the summer of 2015, the garden’s then-prized corpse flower, Spike, failed to bloom at all, despite the cheers of tens of thousands of visitors.

Although they have since had two successfully smelly blooms—Alice, in September 2015, and Sprout, in April 2016—the memory of Spike’s refusal has everyone on edge. “Whether the plants bloom, or when they bloom, is always an open question,” the CBG writes. (If you want to stay in the know, you can sign up for email bloom alerts or track #CBGTitanTwins on Twitter.)

Regardless of what happens, the CBG has twelve more corpse flowers in the production greenhouses, waiting for their time in the spotlight. Fear not, Chicago: Your city will stink for years to come.

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