Spotlight on Science: Tom Croat

A monthly look at the people behind plant science at the Missouri Botanical Garden

Dr. Tom Croat
P.A. Schulze Curator of Botany

Tom Croat has been called the Indiana Jones of botany, and when you hear him describe his collecting journeys to the Tropics, it fits.

Croat, 80, has spent about a third of his 51 year-career at the Missouri Botanical Garden in faraway places, mostly Central and South America, where he climbs trees gathering plant samples, often setting records in how many he collects. The trips can get dangerous. Croat’s fallen out of trees several times. He’s fallen off a cliff. He’s come face-to-face with a wasp nest. He once cut the tip of his finger off with a machete (doctors were able to reattach it later.) And there was the time he was on a collecting trip in Mexico and found himself surrounded by men in trucks with guns claiming to be law enforcement—Croat didn’t buy it, but managed to get out of the situation unscathed.

Croat loves to share the stories of his adventures, but he prefers to call himself a “mega collector” rather than Indiana Jones. By his definition, a mega collector has collected plants for a long time, from many different places and with a specific motive, like an interest in a certain species or plant family. Croat easily meets all three stipulations with his work on aroids.


The Aroid Authority 

Croat has collected countless aroid specimens and described more than 3,000 new species, perhaps more than anyone alive. He’s visited 100 countries and collected in 40 countries. His journeys have taken him to every country in Central and South America, as well as other places like Madagascar. “I have the best job in the world and I wouldn’t trade it for any job in the world,” he says.

View rarely seen specimens from the Garden’s world-renowned aroid collection on display for a limited time

Even before Croat’s long career at the Garden began, plants were a part of his life. He grew up on a farm in Iowa, taking on most of the work at age 11 after his father passed away.  But he only knew the common names for plants, like rye grass and smart weed, until he went to college. There, his professor, Jack Carter, impressed Croat with a vast knowledge of scientific plant names and prompted his infatuation with plant classification. He wasn’t able to take Carter’s plant taxonomy class, but he did go on a few field trips with him, observing topography and wildlife.

After Croat graduated with a teaching degree, he moved to the Virgin Islands and taught high school. It was on the islands that he first started collecting plants, drying the specimens in the oven of the tiny efficiency apartment he shared with a music teacher. Teaching, it turned out, wasn’t Croat’s calling, so after he wrapped up the school year he embarked on a three month journey through South America, visiting all kinds of botanical gardens and seeing unique vegetation in the 18,000 miles of landscape he covered.

Croat’s extensive travels, along with his ability to speak fluent Spanish, landed him a spot in graduate school at the University of Kansas, where he studied botany. KU is also where he met his wife, Patricia. Although Croat was most fascinated by tropical plants, he ended up working on goldenrods, native to the Great Plains of North America, for his PhD. To collect the plants, he travelled to every county of the Great Plains in his Volkswagen Bug, drying plants on the back of the motor and sleeping in the car (he’d removed the passenger’s seat and replaced it with an air mattress).

Photo by Phoebe Mussman

Croat enjoyed the work, but his interest in tropical plants remained, so as graduation approached, he contacted the Missouri Botanical Garden to see if there were any opportunities to work on their Flora of Panama project. The Garden ultimately hired him to work on a new project, Flora of Barro Colorado Island, sending him to the island in Gatun Lake in the middle of the Panama Canal.

While the island is only 6 square miles, it is home to more than 1,500 plant species—more than in all of the Great Plains—which provided ample opportunity for collection and discovery.

Croat continued to explore and collect in tropical areas throughout his career, taking collecting trips nearly every one of his 51 years at the Garden. Due largely to his work, the Garden now has the largest collection of herbarium material for aroids and the largest living collection of aroids. About 98 percent of the Garden’s three research greenhouses, which contain about 8,000 plants, are species of aroids devoted to Croat.

Photo by Kat Niehaus

“The greenhouse has been marvelous,” Croat says, adding that he was able to request exactly how much space he needed for his collection.

The support and resources from the Garden make it an ideal place for Croat to do his research. He also enjoys a great deal of autonomy, and can pick when and where he goes to collect. Most recently, he spent time in Colombia, Peru and Mexico last year. Although he is 80, Croat isn’t planning to slow down too much. He claims he’s thought about going to “part-time,” but to him that means cutting an 80-hour work week down to 40 hours.

“I can’t afford to quit because of the amount of work that is left.”

Croat thinks there could be as many as 10,000 or 20,000 undescribed aroids in South and Central America.


Dr. Tom Croat presents the 2018 John Dwyer Public Lecture in Biology at the Missouri Botanical Garden.


Catherine Martin
Public Information Specialist

2 Comments Add yours

  1. Ellen Croat Celsi says:

    To my dearest brother Tom: What a great story and so informative. You make me so proud!!

  2. Sid says:

    You are an inspiration to every Aroid lover out there! Wish we could grab a drink and talk through a few of your collection adventures.

Leave a Reply