genus. The entries under the genus Abelia, for 

 example, include the species chinensis, followed 

 by the cultivar 'Edward Goucher', the hybrid 

 Xgrandiflora, and the cultivars 'Prostrata' and 

 'Sherwoodii'. 



In horticultural works, authorities for cultivar 

 names are not required according to the Culti- 

 vated Code. In nursery lists and in many publi- 

 cations on landscape plants, authorities for 

 botanical names are usually omitted, but this is 

 a mistake and leads to confusion. The citation of 

 authorities clearly identifies the botanical name 

 with its correct author(s), for example, Aesculus 

 Jlava Solander, not of Aiton. In another example, 

 the name Acer parviflorum was applied by 

 Ehrhart in 1789 to A. spicatum Lamarck (1786) 

 and later by Franchet & Savatier in 1879 to the 

 plant now known as A. nipponicum Hara. Be- 

 cause of Ehrhart's earlier use of the specific 

 epithet (though illegitimate because of Lamarck's 

 priority) , the Franchet & Savatier name was a 

 "later homonym" and therefore illegitimate. 

 Without an author citation, a reference to the 

 name A. parviflorum would not inform the reader 

 whether A. spicatum or A. nipponicum was 

 meant. 



Subspecies 



The subspecies, abbreviated ssp. or subsp., 

 follows the rank of species and is often used to 

 categorize geographic or ecological variants of a 

 polymorphic species into generally disjunct 

 morphological units. These units may be iso- 

 lated from each other by latitude, longitude, 

 altitude, and by ecological or geographical fac- 

 tors, as well as by morphological characters. 

 Botanists still disagree on the application of the 

 subspecies category, especially when the distinc- 

 tions among variants are ill defined. Examples of 

 subspecies in the catalog include Acer negundo 

 L. ssp. mexicanum (DC.) Wesmael, Hydrangea 

 anomala D. Don ssp. petiolaris (Sieb. & Zucc.) 

 McClint., and Koelreuteria elegans (Seemann) 

 A.C. Sm. ssp. formosana (Hayata) F.G. Meyer. 



Varietas 



The category varietas, or botanical variety (abbre- 

 viated var.) was long used as the only infraspe- 

 cific category generally recognized by botanists. 

 Because of difficulties in evaluating morphologi- 

 cal characters in plants, the categories subspe- 

 cies and varietas have been used interchangeably 

 by different workers. There is no common agree- 

 ment among botanists on the application of these 



categories. As indicatedjDy Cronquist, "Nowa- 

 days one taxonomist's subspecies is likely to be 

 another's variety" (1988, p. 99). Varieties are 

 recognized in many genera in this catalog. In the 

 genus Acer, for example, we recognize Acer 

 rubrum L. var. trilobum T. & G. ex K. Koch, A. 

 rubrum L. var. drummondii (Nutt.) Sarg., A. 

 palmatum Thunb. ex JA. Murr. var. amoenum 

 (Carr.) Ohwi, and A. saccharum Marsh, var. 

 rugelii (Pax) Rehd. 



Forma 



The category forma (abbreviated f.) has long been 

 applied to distinguish transitory variation with- 

 out persistent biological significance that is 

 found randomly within populations of wild 

 plants. Such variation includes flower color, leaf 

 size, leaf shape, plant habit, vesture (hairiness, 

 for example), and other characters. The following 

 examples illustrate the use of forma in three well- 

 known native woody plants cultivated in the 

 southeastern United States: pink flowering 

 dogwood (Cornus florida L. f. rubra (Weston) 

 Schelle), yellow-fruited flowering dogwood 

 {Cornus florida L. f. xanthocarpa Rehd.), and the 

 yellow- fruited American holly [Rex opaca Ait. f. 

 xanthocarpa Rehd.). 



Before the term cultivar was adopted by the 

 Cultivated Code in 1953, the category forma had 

 long been in use for many garden plants and also 

 for some wild plants. Examples include Sophora 

 japonica L. f. pendula (Sweet) Zabel and 

 Pseudotsuga menziesii (Mirb.) Franco var. glauca 

 (Beissn.) Franco f. glauca pendula Rueppel that 

 were automatically given cultivar status after 

 1953. These plants are now properly cited as 

 Sophora japonica L. 'Pendula' and Pseudotsuga 

 menziesii (Mirb.) Franco var. glauca (Beissn.) 

 Franco 'Glauca Pendula'. 



Cultivar 



The 1980 edition of the Cultivated Code provides 

 guidelines "to promote uniformity, accuracy, and 

 fixity in the naming of agricultural, horticultural, 

 and silvicultural cultivars (varieties)." The term 

 cultivar (derived from cultivated variety) was 

 included when the Cultivated Code was drawn 

 up in 1953; it denotes "an assemblage of culti- 

 vated plants which is clearly distinguished by 

 any characters (morphological, physiological, 

 cytological, chemical, or others) and which, when 

 reproduced (sexually or asexually), retains its 

 distinguishing characters." 



