American elm,Orme d'amérique,White elm,Soft elm,Water elm,Common elm,American Water Elm
The American elm is a deciduous hermaphroditic tree which, before the introduction of DED, commonly grew to more than 100 feet (30 m) tall with a trunk whose diameter at breast height was more than 4 feet (1.2 m) and whose circumference was more than 150 inches (380 cm) when supporting a high, spreading umbrella-like canopy. The leaves are alternate, 7–20 cm long, with double-serrate margins and an oblique base. The perfect flowers are small, purple-brown and, being wind-pollinated, apetalous. The flowers are also protogynous, the female parts maturing before the male, thus reducing, but not eliminating, self-fertilization, and emerge in early spring before the leaves. The fruit is a flat samara 2 cm long by 1.5 cm broad, with a circular papery wing surrounding the single 4–5 mm seed. As in the closely related European White Elm Ulmus laevis, the flowers and seeds are borne on 1–3 cm long stems. American Elm is wholly insensitive to daylight length (photoperiod), and will continue to grow well into autumn until injured by frost. Ploidy is 2n = 56, or more rarely, 2n = 28. U. americana, Toronto, c.1914 Bark Leaf Foliage Seedlings
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Ulmus - Elms
Winter, Feb, Mar, Apr
Trees, Native Plant, Tree
The American elm has insignificant small green flowers that appear in spring before the foliage emerges. In North Carolina, flowers are available from February to March., Drooping clusters of 3-4, appearing before the leaves, small, hairy.
The flowers give way to single-seeded wafer-like samaras (each tiny seed is surrounded by a flattened oval-rounded papery wing). The seeds mature in April-May as the leaves reach full size. In North Carolina, fruits are available from March to April., Samaras ovate to oval, veiny, flat, smooth on the faces but densely ciliate along the edges, with a small perforation near the top.
How to Grow
Full Sun, Full sun (6 or more hours of direct sunlight a day), Partial Shade (Direct sunlight only part of the day, 2-6 hours), Sun, Part Shade
Moist, fertile soils. Sandy, Sandy Loam, Medium Loam, Clay Loam, Clay, Limestone-based
Shade tree, Fast growing, Attractive, Fall conspicuous