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Carolus getting stinky

It’s not as powerful as inside. But Carolus is definitely starting to stink and draw in flies. Spathe has continued to unfurl.

A peek inside.

A peek inside.

Carolus opening tonight

Carolus this afternoon, just minutes before starting to open.

Carolus this afternoon, just minutes before starting to open.

A little before 4 p.m. this afternoon, Carolus started showing signs that tonight might be the night. Now, we’re confident that it is.

We’re anxiously watching to see whether or not it will bloom with the same vigor that our Titan arums have bloomed inside the controlled confines of the Conservatory and Kenneth Post Lab Greenhouses during previous flowerings. Or have the chilly Ithaca temperatures (compared to Sumatra) taken its toll on Carolus’s energy reserves. Time will tell whether or not the spathe will unfurl fully and how the stench will compare with earlier flowerings.

We’re also anxious to see what carrion-loving pollinators will be attracted by Carolus’s odor.

Stop by Minns Garden to join the fun. Map.

Parking on campus is restricted most weekdays during the day. But most lots near Minns Garden are unrestricted after 5 p.m. Please observe parking regulation signs.

During the day, the nearest public metered lot is the Peterson Lot at the corner of Tower Road and Judd Falls Road, across from Stocking Hall and the Cornell Dairy Bar.

Carolus less than an hour later, with the spathe pulling back from the spadix.

Carolus less than an hour later, with the spathe pulling back from the spadix.

Carolus getting close

Cornell University Agricultural Experiment Station greenhouse grower Trey Ramsey measures Carolus at 73.5 inches Sunday morning.

Cornell University Agricultural Experiment Station greenhouse grower Trey Ramsey measures Carolus at 73.5 inches Sunday morning.

After more than a week of robust 3- to 4-inch growth daily, Carolus’s has slowed down over the last two days to 2 inches or less. (View growth chart.)

That’s a good sign, along with changes in coloration, that flowering will come soon — possibly early this week.

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Carolus still going strong

carolus in minns

Over the last week, Carolus has grown 20 inches and now stands 56 inches tall in Minns Garden (map). And the towering Titan arum is still adding about 3 inches a day.

The last time Carolus bloomed in 2015 in the Kenneth Post Laboratory Greenhouses, it peaked at 76 inches tall.

When, exactly, will Carolus unfurl its spathe and begin emitting its pungent odor designed to draw in flies, beetles and other pollinators attracted by the prospect of finding a rotting animal carcass? That will be even more difficult to predict this time around due to Carolus being outside the controlled environment of a greenhouse.

But there are signs to look for, based on previous indoor flowerings.  A few days before peak, growth will begin to slow and the spathe will begin to show some reddish tinges. Then when the day arrives, late in the afternoon the spathe will start to pull away from the spadix and the show is on.

Hopefully. Even when flowering inside a cozy conservatory, Titan arums at other institutions have occasionally been known to simply run out of energy and never fully open. We’re prepared for that eventuality, as well. Either way, Carolus is already a showstopper in the garden.

If you’d like to be notified when Carolus starts to open, please sign up for email updates (right column or below on mobile).

Carolus stands 56 inches tall in Minns Garden on July 31.

Carolus stands 56 inches tall in Minns Garden on July 31.

Titan arum to bloom – outside

Carolus stands three feet tall in Minns Garden on July 24

Carolus stands three feet tall in Minns Garden on July 24

‘Carolus’ – one of two flowering-sized Titan arums (Amorphophallus titanum) in the Liberty Hyde Bailey Conservatory’s collection – has broken dormancy and is preparing to bloom this summer.

But instead of unfurling its pungent inflorescence in the confines of the Conservatory, this year’s flowering will take place outside in Minns Garden, between the Plant Science Building and Tower Road.

“As far as we are aware, this is the first time anyone has tried this outside in a temperate region,” says Kevin Nixon, professor in the Plant Biology Section of the School of Integrative Plant Science and the Conservatory’s curator.  Titan arums produce the largest unbranched inflorescences in the plant world.

Paul Cooper, the Cornell University Agricultural Experiment Station greenhouse grower who maintains the Conservatory’s collection, planted Carolus’s massive 100-pound corm – an underground structure similar to a flower bulb – on June 14 in a pot in Minns Garden.  As of July 25, Carolus stood 38.5 inches and was growing about three inches per day.  (See Carolus’s growth chart to follow the plant’s progress.)

When it last bloomed in 2015, Carolus topped out at 76 inches tall. But predicting exactly when the inflorescence will peak this time around will be especially difficult, as the cooler temperatures outside could slow its progress. Best estimate right now is early to mid-August.

And the plan is not without some risk due to the possibility of severe weather or the plant not acclimating well to outdoor conditions in Ithaca and failing to fully develop. “Whatever happens, we’ll learn something new this year,” says Karl Niklas, Liberty Hyde Bailey professor in the Plant Biology Section of the School of Integrative Plant Science.

Read more and follow Carolus’s progress at the Liberty Hyde Bailey Conservatory website.