Lycium L.
Lycium is a genus of ca. 80 species, native in warm-temperate areas of both hemispheres (but predominantly in the New World). Some species are cultivated as ornamentals, especially for hedging in coastal areas.
All current knowledge on the genus is gathered by "Project Lycieae" at http://www3.amherst.edu/~jsmiller/LycieaeWeb/Project_Lycieae.html.
- Corolla tube longer than the corolla lobes (corolla divided less than ½ way to base), cylindrical. Corolla usually less than 17 mm across, its lobes sparsely ciliate at margin or not at all. Largest leaves narrowly elliptic, very gradually narrowed at both ends, widest at the middle. Plant always spiny === 1. Lycium barbarum
- Corolla tube shorter than the corolla lobes (corolla divided at least ½ way to base), campanulate. Corolla usually more than 17 mm across, its lobes densely ciliate at margin. Largest leaves ovate, abruptly rounded at both ends, widest below middle. Plant sometimes less spiny === 2. L. chinense
Literature:
Bernardello L.M. (1986) Revisión taxonómica de las especies sudamericanas de Lycium (Solanaceae). Bol. Acad. Nac. Cien. 57(3-4): 173-356.
Chater A. (2006) Identification of Lycium. BSBI News 102: 50-51.
Feinbrun N. (1968) The genus Lycium in the Flora Orientalis region. Collect. Bot. 7: 359-379.
Haegi L. (1976) Taxonomic account of Lycium (Solanaceae) in Australia. Austr. J. Bot. 24: 669-679.
Hitchcock C.L. (1932) A monographic study of the genus Lycium of the western hemisphere. Ann. Missouri Bot. Gard. 19: 179-374.
Krausch H.-D. (2007) Bocksdorne in Mitteleuropa: Zur Taxonomie und Chorologie der Gattung Lycium L. Beiträge zur Gehölzkunde 2007: 98-105.
McKean D.R. (2000) Lycium. In: Cullen J. & al. (eds.), The European Garden Flora, vol. 6. Cambridge University Press, Cambridge: 251-252.
Stace C. (2010) New flora of the British Isles, 3th ed.: XXXII + 1232 p. Cambridge University Press.
Zhi-Yun, Z., An-Ming, L. & D,Arcy, W.G. (1994) Lycium. In Raven, P. H and Wu, Z. Y. (eds.) Flora of China. 17. -Science Press, Beijing and Missouri Botanical Garden: 301-304.