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.
For the 2015 Canadian film, see Calla Lily (film). For the Philippine TV series starring Sharlene San Pedro, see Calla Lily (TV series). For the Filipino band, see Callalily. Calla lily is a common name for a type of plant. It may specifically refer to: Calla, a genus of common flowering plant in the family Araceae, containing the single species Calla palustris, native to cool temperate regions of the Northern Hemisphere.