A number of conifers are called “cedar,” both formally and colloquially, which makes for some taxonomic confusion. True cedars, however, are a small handful of magnificent evergreens native to the Mediterranean basin and the Himalayas. The two North American conifers called “white-cedars” are unrelated relatives of junipers and bald-cypresses.
There are four trees comprising the genus Cedrus, the true cedars, and all are native to mountains of the Old World: the deodar cedar of the western Himalayan Mountains; the cedar of Lebanon from the highlands of Syria, Turkey and Lebanon; the Cyprus cedar of that island’s mountains; and the Atlas cedar of North Africa’s Atlas and Rif ranges. All are large, burly trees of stiff, whorled needles; thick tight-scaled cones borne upright on the twig; and broad branches often forming a tiered, flat-topped canopy. Massive old veterans of the deodar, Lebanese and Atlas species may exceed 11 feet in diameter and soar beyond 130 feet tall.
Several species of conifers in the cypress family are called “white-cedars” in North America, though their physical resemblance to true cedars is marginal. The northern white-cedar, also called eastern arborvitae, is native to eastern Canada, the Midwest and the Northeast, with scattered populations trending southwestward along the Appalachian Mountains. Frequently it grows as a small- to medium-sized trees 50 feet or less in height, but exceptional specimens may exceed 100 feet tall. The Atlantic white-cedar grows along the Atlantic-Gulf Coastal Plain east and south of typical northern white-cedar range. Both have tight-packed, scaly leaves and fibrous bark.
True cedars often grow in pure stands in mid- to high-elevation forests. For example, the deodar cedar historically formed groves above lower-elevation belts of pine forest in the Hindu Kush Mountains of Afghanistan and Pakistan, extending up the slope past 10,000 feet. In Morocco’s Atlas Mountains, the Atlas cedar often grows at between 4,000 and 8,200 feet in elevation. In North America, Atlantic white-cedar swamps are common along backwaters and floodplain bottoms of the coastal plain. Ancient specimens of northern white-cedar, exceeding 1,000 years in age, grow scraggly and tough from cliffs edging Lake Superior. The same tree in a different ecological setting forms swamps in the boreal and mixed hardwood forests of the Upper Midwest; these white-cedar swamps are some of the wildest spots in the region, sheltering moose and black bear.
White-cedars belong to the diverse family Cuppressaceae, a truly remarkable collection of conifers that collectively inhabit the broadest range of the gymnosperms -- the “naked-seed” plants -- distinct from the angiosperms, or flowering plants. The family includes the biggest trees in the world, the giant sequoias of California’s Sierra Nevada, as well as the tallest, the coast redwoods of that state’s Pacific coast (and a small slice of southwestern Oregon). True cedars, meanwhile, are members of the pine family, Pinaceae.