The plant doesn't look as if it had an unusual story to tell. A type of sedge, it tops out at a foot (0.3 meters) tall and has leaves that look just like blades of green grass.
But after this plant turned up in a Mississippi cemetery four years ago, botanists put on their detective hats to figure out how it got there. The weedy species had never been found in North America before then.
Their main theory centered around a grave belonging to the so-called "Queen of the Gypsies."
Charles Bryson, a research botanist with the United States Department of Agriculture, recalls how he became involved in the mystery. In 2007, a graduate student named Lucas Majure came across an unknown type of sedge in Rose Hill Cemetery in the city of Meridian. He asked Bryson, who worked for the federal department's Agricultural Research Service, to help identify the plant.
"He showed it to me, and I immediately knew it was something new to science or something I had never seen in the U.S.," Bryson told LiveScience. "I have studied sedges for almost 40 years. I know them well enough to know if there is something different or unusual or new."
The plant turned out to be Carex breviculmis, or blue sedge, a widespread weed found in Asia, Australia and New Zealand.
Now they knew what it was, the botanists needed to figure out how it arrived in Rose Hill Cemetery. It first turned up in a shaded area near the fence, and it later became more widely distributed in turf and around grave markers.
Besides Rose Hill, it was also found near a railroad, in a vacant lot behind a fast-food restaurant, and growing by the thousands in a larger cemetery, Magnolia Cemetery Perpetual Care. It has now been identified in eight sites.
There are the usual suspects when investigating the appearance of a foreign species: railroads, air travel, interstate highways, plant nurseries. But surveys of Key Field, the location of a regional airport, and Meridian's Naval Air Station didn't turn up any more plants. The highways and nurseries also turned out to be unlikely culprits.
Rose Hill Cemetery offered the best explanation. In 1915, a woman known as Queen of the Gypsies, Kelly Mitchell, received a royal burial there — Rose Hill is known locally as Gypsy Cemetery — after dying of complications from childbirth.
Mitchell belonged to the Roma, a people believed to have originated in northern India, but who now live throughout the world. They are also widely known as "gypsies," a derogatory term.
A 2007 column in the local newspaper, the Meridian Star, republished part of a century-old account of Mitchell's passing and described the combination of Romani customs and Episcopal services that led to her burial on Feb. 17, 1915. Mitchell's death was believed to have brought 20,000 people to the small town, and more than 5,000 came to the cemetery to attend the last rites.
"Members of the Mitchell Tribe, at the time one of the largest in the country, came to Meridian from all parts of the United States to pay tribute: a newsreel was made and exhibited throughout the country relating the mystery and homage paid to a woman of high esteem as she made her final journey to be laid to rest," columnist Anne McKee wrote.
Even now homage continues to be paid to the Queen, who has since been joined by other notable Roma individuals, McKee noted. The columnist quoted the cemetery director as saying he has found gifts, including a diet Coke and a sack from Burger King, left for her. [Top 10 Weird Ways We Deal With the Dead]
Bryson believes visitors to the cemetery also brought the sedge along, unintentionally.
"It could have come in as a contaminant on clothing, on a cuff of a pant leg or a pocket, or mud on the sole of a shoe. Or it could have been somebody bringing soil from their native land and sprinkling it over the grave site, or it could have come from a plant that was brought in and set out at the graveside, if it had seeds in the soil," Bryson said. "All these are possibilities."
While the sedge was also found by railroad tracks, it was only in places near campgrounds used by vagrants and other transients.
The plants appear to have been established in the Meridian area for several decades, and it's possible they were spread between cemeteries by maintenance equipment, according to Bryson.
He fears the sedge has the potential to become a U.S. weed that will create problems for lawns, turf and fruit and nut tree seedlings.
The research was featured in the October 2011 issue of the USDA's Agricultural Research magazine.
Editor's note: This article was updated on Jan. 12, 2017, to correct language that provided inaccurate representations of Roma people.