Dogwood [Latin cornu, horn, alluding to the hard wood] Dogwood [Latin cornu, horn, alluding to the hard wood]

Herbs, shrubs, or trees, clonal from rhizomes, rooting from decumbent branches, or aclonal; hairs 1-celled, arms either short and ornamented with micropapillae and calcium carbonate crystals, or long, erect, curling, and twisted. Leaves: blade lanceolate to broadly ovate; abaxial surface often papillate. Inflorescences: bracts adnate to inflorescence branches, distal portion either minute and caducous or expanding into showy, nonchlorophyllous involucres. Pedicels present or absent. Flowers: hypanthium turbinate or urceolate; petals spreading or recurved, usually cream, rarely purple; stamens exserted; anthers dorsifixed, versatile. Drupes globose, subglobose, or ellipsoid, slightly fleshy. x = 11.

Species ca. 60 (20 in the flora): North America, Mexico, Central America, n, w South America, Eurasia, Africa; predominately northern boreal and temperate regions, also high elevations in subtropical and tropical regions.

Cornus as treated here is a monophyletic genus (Z. E. Murrell 1993; Xiang Q. Y. et al. 2006) that has at various times been more narrowly circumscribed by other authors who have chosen to recognize morphological variation in this diverse group as worthy of generic segregation [for example, Arctocrania (Endlicher) Nakai, Benthamia Lindley (not A. Richard), Benthamidia Spach, Chamaepericlymenum Hill, Cynoxylon (Rafinesque) Small, Eukrania Rafinesque, Macrocarpium (Spach) Nakai, Swida Opiz, and Thelycrania (Dumortier) Fourreau]. Cornus is retained here as a coherent group, maintaining subgenera as more appropriate biological units for recognition of this variation.

Some North American members of Cornus are susceptible to fungal pathogens that may cause severe species decline, such as Dogwood Anthracnose (Discula destructiva) in association with C. florida and C. nuttallii, or the less virulent but still destructive Cryptodiaporthe Canker (Cryptodiaporthe corni), which is restricted to C. alternifolia.

SELECTED REFERENCES Eyde, R. H. 1988. Comprehending Cornus: Puzzles and progress in the systematics of dogwoods. Bot. Rev. (Lancaster) 54: 233–351. Ferguson, I. K. 1966. Notes on the nomenclature of Cornus. J. Arnold Arbor. 47: 100–105. Ferguson, I. K. 1966b. The Cornaceae of the southeastern United States. J. Arnold Arbor. 47: 106–116. Murrell, Z. E. 1992. Systematics of the Genus Cornus (Cornaceae). Ph.D. dissertation. Duke University. Murrell, Z. E. 1993. Phylogenetic relationships in Cornus (Cornaceae). Syst. Bot. 18: 469–495.