redwoods listed by Monumental Trees are both in the Longwood Gardens of Kennett Square in Pennsylvania, United States. The widest has a girth at breast height of , average diameter , and is tall. The tallest is tall, and has a girth at breast height of , average diameter . Both trees were planted in 1948 and measured in 2018. Ecotypic variation Ecotypic variation has developed in a variety of microhabitats. Three variations have been observed based on the size of their cones, large, medium, and small. The large cone type is found growing on mountain slopes, develops a broad canopy, seeds more readily and is more drought tolerant. The small cone type is found near stream banks, is more sensitive to drought, and develops a more uniform trunk. Related species Together with Sequoia sempervirens (coast redwood) and Sequoiadendron giganteum (giant sequoia) of California, M. glyptostroboides is classified in the subfamily Sequoioideae of the family Cupressaceae. Although it is the only living species in its genus, three fossil species are known as well. The other Sequoioideae and several other genera have been transferred from the Taxodiaceae to the Cupressaceae based on DNA analysis. Conservation Studies carried out between 2007 and 2009 counted 5,371 trees primarily in Lichuan, Hubei, with much smaller groups in Shizhu, Chongqing and Longshan, Hunan. The floodplain of Metasequoia Valley in Hubei had already been turned to rice paddies by the time of the tree's discovery, but was once probably a more extensive dawn redwood forest. Such a forest would have been similar to bald cypress forests in the United States, with many similar species growing in association. Nearly 3,000 trunks were found in the floor of the valley, ranging from wide at the base. Additionally, houses made of Metasequoia wood 200–300 years old still exist and probably date back to the original settlement of the valley. Since its discovery, the dawn redwood has become something of a national point of pride, and it is protected under Chinese law and also planted widely. However, it is still listed as endangered in the wild. Cutting of trees or branches is illegal, but the demand for seedlings drives cone collection to the point that natural reproduction is no longer occurring in the dawn redwood forest. In addition, the landscape has been highly modified by human use, and a 1980 expedition found that the habitat has significantly degraded since the