Mandarin trees, of which satsumas and tangerines form a part, are a class of orange originally native to South East Asia. Generally, mandarin trees are generally somewhat smaller than orange trees. However, they can reach 25 feet in height in the case of very old trees. Leaves can be either broad or slender pointed at the tip and rounded at the base. The fruit itself is classified as a berry (hesperidium) and is bright orange or reddish orange when ripe. Somewhat smaller than oranges, mandarins are also distinguished by a loose peel which can easily be pulled away from the flesh. The good news for home landscapers in marginal citrus-growing areas is that mandarins/tangerines/satsumas are some of the most cold-tolerant members of the citrus clan. The 'Changsa' variety of mandarin, for instance, has been recorded as surviving a temperature drop to 4ºF, remarkable for a citrus. However, this does not mean that precautions are not necessary when freezing conditions threaten. Consult a tree care specialist for the variety most appropriate for your climate and region.