Deep in a lush remote valley in the Dominican Republic, the discovery of a single very special tree spawned a new species of avocado.

Called the Carla, it has since emerged as a rock star of the avocado world, combining the buttery richness of the popular-but-small California-grown Hass with the prodigious size of Florida varieties. The Carla created a sensation when a high-end British retailer began stocking it.

Now, the Carla's patent holder is in Miami federal court suing to protect its exclusive rights to sell a valuable product sought by trendy foodies. With allegations of tree-branch theft, clandestine cloning and DNA tests on competitors' produce, it's not your everyday patent infringement case.

Agroindustria Ocoeña, the Dominican company that holds a U.S. patent for the Carla, is suing a Miami produce distributor, Fresh Directions International, claiming that it is illegally selling Carlas in south Florida from another grower. They aren't knockoff avocados either, the lawsuit argues. DNA tests show they are virtual Carla clones, which the suit suggests can mean only a grifted graft — somebody pruned and pilfered Carla tree branches to recreate their own orchard.

Fresh Directions did not return a call for comment.

The lawsuit comes with demand for avocados skyrocketing in many international markets, including America, where avocado toast now rivals guacamole in popularity. California leads the United States in avocado production. Florida is second.

The single tree that produced the first Carla avocados was discovered by Carlos Antonio Castillo Pimentel in 1994 in his orchard in the Ocoa River Valley. Why he named the fruit Carla isn't explained in court or patent documents but there are several traits that made it attractive to the grower. For one, the tree produces fruit later and longer than similar species and can be harvested from February into early June, well after the Florida growing season.

"It helps fill a gap in the calendar year," said Peter Leifermann of produce shipper Brooks Tropicals. "We are able to supply the market with green-skin avocados nearly 12 months a year."