Science & Nature

Endangered Corpse Flowers in Botanical Collections Could Be Inbred to Extinction Due to Shoddy Recordkeeping: Study

Titan arum (Amorphophallus titanum) is a rock star in the plant world.

The infrequent and foul-smelling blooms of the so-called “corpse flower” — housed in botanic gardens and arboretums around the world — are the stuff of legend: livestreamed to a global audience while also attracting tens of thousands of admirers in person, many of them waiting in line around the clock to catch a glimpse of the towering spike but mostly a whiff of the scent described as “rotting flesh.”

The publicity surrounding these events — including the blooming of Sprout, Alice and Java in Chicago — has brought much-needed attention to the endangered status of Titan arum. But newly published research suggests that despite all the pampering these plants receive from their curators, conservation efforts have fallen short in one key area that threatens the species’ survival in captivity as much as in the wild.

When plant biologists from Northwestern University and the Chicago Botanic Garden conducted a study of data from nearly 1,200 individual Titan arum plants held in collections at 111 institutions, they found an alarming amount of inconsistency in the information provided.

In short: Poor record-keeping meant a lot of the plants lacked a proper family tree, and unhealthy inbreeding had run rampant as a result.

“The population needs variation to survive,” Olivia Murrell, lead author of the study, said in a statement. “If nothing changes, it could inbreed itself into extinction…. We don’t think people are consciously making the choice to inbreed their plants. They just don’t know what they have because the data are incomplete." (Murrell was a graduate student at the time of the study and is now pursuing a doctorate in the United Kingdom.)

Olivia Murrell (left) studying corpse flowers. (Courtesy of Olivia Murrell)

Only an estimated 162 individual Titan arum plants are thought to exist in the wild. Found solely on the island of Sumatra in Indonesia, the population of corpse flowers has declined due to habitat fragmentation and loss, climate change and overharvesting.

In addition to its endangered status, the plant is also considered “exceptional,” in that its seeds can’t be effectively saved in seed banks for future reproduction. It’s this exceptional status that places even greater importance on the specimens held in “living collections,” such as the ones found Chicago Botanic Garden, if Titan arum is ever to recover in the wild.

Murrell and her colleagues posited that plants such as Titan arum would benefit from the same sort of breeding programs zoos and aquariums have adopted for their own endangered species, in which swaps are recommended between institutions to maintain genetic diversity. The use of such a pedigree-based approach has led to the successful conservation and reintroduction of species including the California condor.

But in order to recommend the optimum pairings between males and females, it’s crucial to know the lineage of the individuals.

And that’s the data the researchers found missing for Titan arum. Often there was no information about a plant’s origin, parents or propagation.

“The highest rate of missing data occurred when plants were transferred to new locations,” Murrell said. “The plants moved, but their data didn’t move with them. So, records easily got lost over time as plants moved around.”

In the absence of pedigree information and the lack of a breeding program, researchers found that of the plants included in the Titan arum study, 24% were clones and 27% were offspring from two closely related individuals (i.e., inbred).

Low genetic diversity carries a number of risks. In addition to an overall decrease in fitness, inbred plants might produce less pollen or be more susceptible to disease and pests.

“One institution reported that, possibly as a result of inbreeding, all their corpse flower offspring were albino, so they didn’t survive because they didn’t have chlorophyll to photosynthesize,” Murrell said.

With 45% of all flowering plants threatened with extinction, the study concluded the preservation of remaining biodiversity should be prioritized within collections.

The researchers recommended that botanists begin to act and think more like their zoo and aquarium counterparts, with rigorous, standardized and centralized record-keeping being paramount.

“Not keeping data has clear conservation implications,” Murrell said.

Read the complete study in the Annals of Botany.

Contact Patty Wetli: @pattywetli | (773) 509-5623 |  [email protected]

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