Pollination habits of endangered Texas rice revealed to help preservation

A type of wild rice that only grows in a small stretch of the San Marcos River is likely so rare because it plays the sexual reproduction game poorly, a study led by the Lady Bird Johnson Wildflower Center at The University of Texas at Austin has revealed.

The first study of breeding habits of this endangered, aquatic grass (Zizania texana) found that the pollen of Texas wild-rice can only travel about 30 inches away from a parent plant. If pollen doesn't land on a receptive female flower within that distance, no seeds will be produced. No seeds means no new plants to replenish a population that faces other survival threats.

"It would be great to introduce more of these plants into the San Marcos River so that we can build up its population, said Flo Oxley, conservation director at the Wildflower Center, and lead author of the study.

"This information will be useful when reintroduction efforts begin, because we now know that lots of new plants must be planted close together in order for seeds to be produced."

The findings were published in June in The Southwestern Naturalist journal of the Southwestern Association of Naturalists, and shared with staff at the U.S. Fish and Wildlife Service and the Texas Parks and Wildlife Department.

The U.S. Fish and Wildlife Service is the principal federal agency responsible for federally listed species conservation. Texas has about 25 percent of the plant biodiversity nationally, including 23 endangered and five threatened plant species.

Texas wild-rice prefers the clean, clear water of the San Marcos River and is not found anywhere else. The plant spends most of its life submerged, emerging only to flower. Recreation on the river can stir up sediments that prevent sunlight from reaching the plants, and swimmers, tubers and canoers often submerge the plants' flowers so they can't pollinate. This foot traffic isn't expected to go away soon, and the flow of underground water into springs that feed the river is also decreasing as the Central Texas population expands and drinking water needs increase.

"Nobody intends to shut down access to the river because of these plants" Oxley said, "and I've been surprised at how respectful of the plant people are when they learn that it is an endangered species that grows only in the San Marcos River and nowhere else in the world. Texans are very proud and protective of their natural history, and I believe they will take care of Texas wild-rice if we just let them know about it."

It doesn't hurt, she added, that Texas wild-rice serves as home for tiny invertebrates that have nasty feeding habits.

"People who swim through Texas wild-rice risk picking up these aquatic hitchhikers and may end up with itchy behinds for their efforts," she said.

Texas wild-rice is a food source and home for endangered fish called fountain darters, and is a cousin to several rice species cultivated for food purposes. But it is among more than 200 plant species of concern in Texas whose fundamental value isn't understood because so little information has been available to guide conservation or other decisions.

"We don't know what overall purpose this plant serves in the ecosystem, and we don't know what's going to happen if this plant goes away," Oxley said.

Source: University of Texas at Austin

Related stories:

Texas' coastal ecosystem could take a generation to recover from Ike's damage
It was a violent dose of nature to a coast already hammered by decades of pollution, population growth and habitat loss. As scientists and land managers start to assess the storm's impacts on beaches, dunes and marshes, they are seeing signs of present damage and future worries.
Botanists identify new species of North American bamboo
Two Iowa State University botanists and their colleague at the University of North Carolina have discovered a new species of North American bamboo in the hills of Appalachia. It is the third known native species of the hardy grass. The other two were discovered more than 200 years ago.
AP Investigation: Ike environmental toll apparent
(AP) -- Hurricane Ike's winds and massive waves destroyed oil platforms, tossed storage tanks and punctured pipelines. The environmental damage only now is becoming apparent: At least a half million gallons of crude oil spilled into the Gulf of Mexico and the marshes, bayous and bays of Louisiana and Texas, according to an analysis of federal data by The Associated Press.
Beaches once thick with birds quiet thanks to Ike
(AP) -- One of North America's renowned bird migration and bird watching areas is strangely silent. Blame Hurricane Ike.
Bays on US Gulf Coast vulnerable to flooding
The most comprehensive geological review ever undertaken of the upper U.S. Gulf Coast suggests that a combination of rising seas and dammed rivers could flood large swaths of wetlands this century in one or more bays from Alabama to Texas.
From mothballs to mobilization: Taking the salt out of sea water
The United Nations estimates that 1.1 billion people across the globe lack access to sustainable, clean drinking water and that 1.6 million children will die each year because of that lack of access. How can science help provide more drinkable water for a growing population on an Earth with limited fresh surface-water and groundwater resources?
Stalagmites may predict next Big One along the New Madrid Seismic Zone
Small white stalagmites lining caves in the Midwest may help scientists chronicle the history of the New Madrid Seismic Zone (NMSZ) – and even predict when the next big earthquake may strike, say researchers at the Illinois State Geological Survey and the University of Illinois at Urbana-Champaign.
Understanding Algae As An Alternative Fuel Source: Will The Real Algae X Please Stand Up
The recent creation of AXI, LLC is an alliance between Allied Minds, Inc. a seed investment company and the University of Washington. The alliance came about because of Professor Rose Ann Cattolico PhD, an algae-to-fuel expert. Professor Cattolico has been on the faculty and conducting algae research since 1975. Her research includes, chloroplast genome architecture and gene function in non-chlorophy b containing algae and functional genetic diversity within stramenopile population. Professor Cattolico has discovered a unique patented technology, she calls Algae X.

News discussion:

General Science news