Cattails usually live in streams. Its mature  inflorescence looks like a candle, so it is called "water candle." The height can reach up to 2 meters. The straight and cylinder underground stems are in the mud. When Dragon Boat Festival, people usually take its leaves  and put them on the gate to drive bad luck away. The leaves can be used to make ropes, grass mats and fans. Its blossom is during April to September. If putting some oil on its female inflorescence, it really can be a candle! A male flower is on the top of a female flower, it used to be a popular material of flower arrangement art.  Its seeds can be spread by wind. It can propagate itself by its horizontal stems. The front value is that its roots can absorb and filter pollutants in the water.

<Hygrophila pogonocalyx Hayata> --by Yi-Kai, Jing-Jia and Yi-kai

     Look those plants blowing in the wind! They are Hygrophila pogonocalyx Hayata ('water palm-bark rain cape' in literary. ) Here is some information about them.

     Denominating origin: In 1920, a Japanese botanist called B. Hayata found it in Taichung County (in central Taiwan) and called it Hygrophila pogonocalyx Hayata. It is an Endemic species in Taiwan. It is not widely spread only in Da-an village and Qing-shui village where in Taichung. There are 2 types of Hygrophila pogonocalyx Hayata. Both of them are named after the places they grow--Da-an type and Qing-shiu type.

       Present Facts: The figures in 1972 said that there were only a thousand of wild Hygrophila pogonocalyx Hayata left. In Da_an village, although they were protected by local government office and Endemic Species Research Institute, the positive value of Hygrophila pogonocalyx Hayata still couldn't convince the owner of the land which is the habitat. So, wild Da-an type had been extinct. However, in Qing_shui village, people cultivated Hygrophila pogonocalyx Hayata by plugging their stems into the soil. This still maintains their exist with difficulty.

      Differences: In fact, both Da-an type and Qing-shui type are easy to plant with stems. According to the figures provided by Endemic Species Research Institute, the survival rate of cuttage can reach up to 95.4%. But why is this species still endangered? The reason is that they cannot spread their living range because of their inborn condition, which is that they can't fruit after blossom. They can just stay at their land defensing to propgate their species. Therefore, when the habitats are destroyed, they have no choice waiting for being extinct. This is why we use cuttage method to try to keep them.