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Cornus florida (flowering dogwood) is a species of flowering plant in the family Cornaceae native to eastern North America, from southern Maine west to southern Ontario, Illinois, and eastern Kansas, and south to northern Florida and eastern Texas, with a disjunct population in Nuevo León and Veracruz in eastern Mexico. In Ontario, this tree species has been assessed and is now listed as endangered

Cornus florida is easily propagated by seeds, which are sown in the fall into prepared rows of sawdust or sand, and emerge in the spring. Germination rates for good clean seed should be near 100% if seed dormancy is first overcome by cold stratification treatments for 90 to 120 days at 4 °C (39 °F).[4] [5] Flowering dogwood demonstrates gametophytic self-incompatibility, meaning that the plants can’t self-fertilize. This is important for breeding programs as it means that it is not necessary to emasculate (remove the anthers from) C. florida flowers before making controlled cross-pollinations. These pollinations should be repeated every other day, as the flowers must be cross-pollinated within one or two days of opening for pollinations to be effective.[6

Description[edit]
Cornus florida inflorescence, showing four large white bracts and central flower clusterFlowering dogwood is a small deciduous tree growing to 10 m (33 ft) high, often wider than it is tall when mature, with a trunk diameter of up to 30 cm (1 ft). A 10-year-old tree will stand about 5 m (16 ft) tall. The leaves are opposite, simple, ovate, 6–13 cm (2.4–5.1 in) long and 4–6 cm (1.6–2.4 in) broad, with an apparently entire margin (actually very finely toothed, under a lens); they turn a rich red-brown in fall.

The flowers are individually small and inconspicuous, with four greenish-yellow bracts 4 mm (0.16 in) long. Around 20 flowers are produced in a dense, rounded, umbel-shaped inflorescence, or flower-head, 1–2 cm (0.39–0.79 in) in diameter. The flower-head is surrounded by four conspicuous large white, pink or red "petals" (actually bracts), each bract 3 cm (1.2 in) long and 2.5 cm (0.98 in) broad, rounded, and often with a distinct notch at the apex. The flowers are bisexual.

When in the wild they can typically be found at the forest edge and popular on dry ridges. While most of the wild trees have white bracts, some selected cultivars of this tree also have pink bracts, some even almost a true red. They typically flower in early April in the southern part of their range, to late April or early May in northern and high altitude areas. The similar Kousa dogwood (Cornus kousa), native to Asia, flowers about a month later.

The fruit is a cluster of two to ten drupes, each 10–15 mm (0.39–0.59 in) long and about 8 mm (0.31 in) wide, which ripen in the late summer and the early fall to a bright red, or occasionally yellow with a rosy blush. They are an important food source for dozens of species of birds, which then distribute the seeds.

References[edit]

 * 1) Jump up ^ Cappiello, P and D Shadow. 2005. Dogwoods: The Genus Cornus. Timber Press, Portland. pp 98-100.
 * 2) Jump up ^ Anderson, RL, JL Knighten, M Windham, K Langdon, F Hendrix, R Roncadori. 1994. Dogwood anthracnose and its spread in the South. Project Report R8-PR 26. USDA Forest Service, Atlanta, GA. 10pp.
 * 3) Jump up ^ "RHS Plant Selector - Cornus florida 'Cherokee Chief ' ". Retrieved 17 July 2013.
 * 4) Jump up ^ Cappiello, P and D Shadow. 2005. Dogwoods: The Genus Cornus. Timber Press, Portland. pp 100-102.
 * 5) ^ Jump up to: a b Hartmann, HT, DE Kester, FT Davies, RL Geneve. 2002. Hartmann and Kester’s Plant Propagation: Principles and Practices, 7th Edition. Prentice Hall, Upper Saddle River, NJ. pp. 769.
 * 6) Jump up ^ Reed, SM. 2004. Self-incompatibility in Cornus florida. HortScience 39(2): 335-338.
 * 7) Jump up ^ Cappiello, P and D Shadow. 2005. Dogwoods: The Genus Cornus. Timber Press, Portland. pp 102.
 * 8) Jump up ^ Kaveriappa, KM, LM Phillips, RN Trigiano. 1997. Micropropagation of flowering dogwood (Cornus florida) from seedlings. Plant Cell Reports 16: 485-489.
 * 9) Jump up ^ Sharma, AR, RN Trigiano, WT Witte, OJ Schwarz. 2005. In vitro adventitious rooting of Cornus florida microshoots. Scientia Horticulturae 103: 381-385.
 * 10) Jump up ^ Petrides, George A. 1972. A field guide to trees and shrubs; field marks of all trees, shrubs, and woody vines that grow wild in the northeastern and north-central United States and in southeastern and south-central Canada. The Peterson field guide series, 11. Boston: Houghton Mifflin. page 106.
 * 11) Jump up ^ Cappiello, P and D Shadow. 2005. Dogwoods: The Genus Cornus. Timber Press, Portland. pp 100.
 * 12) Jump up ^ "White Dogwood". Virginia Department of Forestry. Retrieved April 7, 2012.
 * 13) Jump up ^ "Cornus florida". Missouri Botanical Garden. Retrieved April 7, 2012.
 * 14) ^ Jump up to: a b "State Flower--Dogwood" (PDF). North Carolina Museum of History. Retrieved April 7, 2012.
 * 15) Jump up ^ "Dogwood Questions and Answers". United States National Arboretum, United States Department of Agriculture. Retrieved April 7, 2012.
 * 16) Jump up ^ "U.S. eyes 3,000 dogwoods for 'sakura' anniversary. The Japan Times. Posted: Jan. 17, 2012". Japantimes.co.jp. Retrieved 2014-03-28.
 * mnr.gov.on.ca