We've all heard about the most endangered animals. Creatures like the critically endangered black rhinoceros are famous, and in some cases have been reduced to just a handful of individuals. But what are the most endangered plants? They might not be as exciting or loveable as animals, but they are just as important to the ecosystem – and humanity relies on that ecosystem. Here are nine of the most threatened plants today. They are almost all classed as critically endangered by the International Union for Conservation of Nature (IUCN). These plants occupy some of the most inaccessible, remote parts of our planet. They are threatened by habitat destruction, illegal collection, poaching, and competition with invading species. Attenborough's pitcher plant (Nepenthes attenboroughii) Attenborough's pitcher plant is known only from the relatively inaccessible summit of Mount Victoria in Palawan in the Philippines. There are thought to be only a few hundred of them. Pitcher plants are carnivorous plants that trap animals in liquid-filled bowls called pitchers. Attenborough's pitcher plant is one of the biggest, with pitchers up to 30cm in height that can trap insects and rats. It was only discovered in 2007 when a team of botanists, tipped off by two Christian missionaries, scaled Mount Victoria. It is named after British natural history broadcaster David Attenborough.

Ancient sturgeon in China's Yangtze 'nearly extinct' This picture taken on 13 April 2014 shows artificially bred Chinese sturgeons released into the Yangtze river in Yichang, central China's Hubei province The Chinese sturgeon, thought to have existed for more than 140 million years, is now on the brink of extinction, according to local media. Xinhua reported that no wild sturgeon reproduced naturally last year in the Yangtze river. It was the first time since researchers began recording levels 32 years ago. Chinese researches say the fall is due to rising levels of pollution in the Yangtze river and the construction of dozens of dams. Researchers from the Chinese Academy of Fishery Sciences also found that no young sturgeons were found swimming along the Yangtze toward the sea during the period they usually do so. A researcher told Xinhua that in the 1980s, at least several thousand sturgeon could be found in the river. It is estimated only around 100 fish remain. "Without natural reproduction, the fish population cannot replenish itself. If there are no further steps taken to strengthen conservation, the wild sturgeon faces the danger of extinction," he said. The finless porpoise, another native species to the Yangtze river, is said to be at risk as well. In recent decades the Chinese authorities have built numerous dams along the 6,300km-long Yangtze river to boost the country's electricity supply. Such moves have drawn criticism of environmental degradation and displacement of villagers.