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.
Division Marchantiophyta&#151Liverworts, genus Marchantia. : The thallus of the haploid gametophyte (n) grows flat on moist ground, and it is many-cells thick. Pores to permit gas exchange are in the top surface, and there are air spaces within the top zone of the thallus. Water is absorbed throughout the surface.
Eucalyptus /ËjuËkÉËlÉªptÉs/ L'Heritier 1789 is a diverse genus of flowering trees and shrubs (including a distinct group with a multiple-stem mallee growth habit) in the myrtle family, Myrtaceae. Members of the genus dominate the tree flora of Australia. small genus of similar trees, Angophora, has also been known since the 18th century. In 1995 new evidence, largely genetic, indicated that some prominent eucalyptus species were actually more closely related to Angophora than to the other eucalypts; they were split off into the new genus Corymbia.