Elms are deciduous and semi-deciduous trees comprising the flowering plant genus Ulmus in the plant family Ulmaceae. The genus first appeared in the Miocene geological period about 20 million years ago, originating in what is now central Asia.[1] These trees flourished and spread over most of the Northern Hemisphere, inhabiting the temperate and tropical-montane regions of North America and Eurasia, presently ranging southward in the Middle East to Lebanon, and Israel,[2] and across the Equator in the Far East into Indonesia. Elms are components of many kinds of natural forests. Moreover, during the 19th and early 20th centuries many species and cultivars were also planted as ornamental street, garden, and park trees in Europe, North America. END
Pin oak is a medium-sized deciduous tree growing to 18–22 m (59–72 ft) tall, with a trunk up to 1 m (3.3 ft) diameter. It has an 8–14 m (26–46 ft) spread. A 10-year-old tree grown in full sun will be about 8 m (26 ft) tall. Young trees have a straight, columnar trunk with smooth bark and a pyramidal canopy. By the time the tree is 40 years old, it develops more rough bark with a loose, spreading canopy. This canopy is considered one of the most distinctive features of the pin oak: the upper branches point upwards, the middle branches are at right angles to the trunk, and the lower branches droop downwards. The leaves are 5–16 cm (2–6+1⁄4 in) long and 5–12 cm (2–4+3⁄4 in) broad, lobed, with five or seven lobes. Each lobe has five to seven bristle-tipped teeth. The sinuses are typically u-shaped and extremely deep cut. In fact, roughly the same amount of sinus area exists as actual leaf area. The leaf is mostly hairless, except for a very characteristic tuft of pale orange-brown down on the lower surface where each lobe vein joins the central vein. Overall autumn leaf coloration is generally bronze, though individual leaves may be red for a time, and is not considered particularly distinctive.[6] The acorns, borne in a shallow, thin cap, are hemispherical, 10–16 mm (13⁄32–5⁄8 in) long and 9–15 mm (11⁄32–19⁄32 in) broad, green maturing pale brown about 18 months after pollination.[8] Unless processed using traditional methods, the acorn is unpalatable because the kernel is very bitter
Live oak or evergreen oak is any of a number of oaks in several different sections of the genus Quercus that share the characteristic of evergreen foliage.[1] These oaks are not more closely related to each other than they are to other oaks. The name live oak comes from the fact that evergreen oaks remain green and "live" throughout winter, when other oaks are dormant and leafless. The name is used mainly in North America, where evergreen oaks are widespread in warmer areas along the Atlantic coast from southeast Virginia to Florida, west along the Gulf Coast to Louisiana and Mexico, and across the southwest to California. Evergreen oak species are also common in parts of southern Europe and south Asia, and are included in this list for the sake of completeness. These species, although not having "live" in their common names in their countries of origin, are colloquially called live oaks when cultivated in North America. When the term live oak is used in a specific rather than general sense. END
