1 The sun's rays are strongest during the hours of 10 a.m. to 4 p.m. The sun's rays are also stronger at higher altitudes and lower latitudes (closer to the tropics). Reflection off water, sand, or snow can make the sun's burning rays stronger.  Sun lamps can cause severe sunburn.
Marchantia polymorpha, sometimes known as the common liverwort or umbrella liverwort, is a large liverwort with a wide distribution around the world. It is variable in appearance and has several subspecies.
General Information on Liverworts. The Marchantiophyta is a category of bryophyte plants which are commonly known as hepatics or liverworts. Each of its cells carry a single group of genetic information ready for the reproduction.here are approximately 6000 â 8000 species of liverwort in total, however, scientists believe that once they take further research into the Neo-tropical regions (Mexican plateau including Central and South America and the West Indies), the number of liverwort species will increase to 10,000.