Sorghum Moench
Sorghum is a relatively small genus of ca. 25-30 species. Most are confined to tropical and subtropical regions of the Old World (mainly Australia and Africa); a single species is native in the New World (Mexico; Mabberley 2008). None is native in Belgium.
Sorghum obviously is a heterogeneous assemblage. Numerous molecular phylogenetic studies have only partly resolved genetic relationships (Guo & al. 2006, Dillon & al. 2007).
Sorghum is an economically important genus. Several species are cultivated as cereal crops, especially in the warm-temperate and subtropical regions of the world. One of these, Sorghum bicolor, is the fourth most important cereal (Mabberley l.c.). Another species, Sorghum halepense, is both a widely grown fodder plant and a noxious agricultural weed.
As a result of intensive crossing the taxonomy of the cultivated species of Sorghum has become very complex, especially in the Sorghum bicolor complex. See further under that species.
- Annual grasses, rarely exceeding 100 cm. Leaves usually more than 25 mm wide. Bisexual (sessile) florets broadly ovate, up to 4(-6) mm wide, (rarely) awned or unawned, usually densely silky hairy, often not or tardily disarticulating. Male or sterile florets up to 6 mm long on pedicels of equal length. Panicle usually compact with short primary branches, usually broadly ovoid in outline === Sorghum bicolor
- Perennial grasses, often more than 150 cm tall. Leaves usually less than 20(-25) mm wide. Bisexual (sessile) florets narrowly ovate, up to 2 mm wide, awned or (rarely) unawned, not silky hairy, always disarticulating at maturity. Male or sterile florets much smaller on pedicels 1-1,5 mm long. Panicle more diffuse with longer primary branches, usually lanceolate in outline === S. halepense
References
Barkworth M.E. (2003) Sorghum. In: Barkworth M.E. & al. (eds.), Flora of North America north of Mexico, vol. 25: 626-630. Oxford University Press, New York-Oxford.
De Wet J.M.J. (1978) Systematics and evolution of Sorghum sect. Sorghum (Gramineae). Amer. J. Bot. 65: 477-484.
Dillon S.L., Lawrence P.K., Henry R.J. & Price H.J. (2007) Sorghum resolved as a distinct genus based on combined ITS1, ndhF and Adh1 analyses. Plant Syst. Evol. 268: 29-43.
Fernandes E.J.H. (2000) An ecogeographic survey of cultivated and wild species of Sorghum in Africa. Birmingham: University of Birmingham: 72 p.
Guo Q., Huang K., Yu Y., Huang Z. & Wu Z. (2006) Phylogenetic relationships of Sorghum and related species inferred from sequence analysis of the nrDNA ITS region. Agricultural Sciences in China 5: 250-256.
Hulse J.H., Laing E.M. & Pearson O.E. (1980) Sorghum and the millets: their composition and nutritive value. London etc., Academic Press: XVI+ 997 p.
Mabberley D.J. (2008) Mabberley’s plant-book (3th ed.). Cambridge University Press, Cambridge: XVIII + 1021 p.
Snowden J.D. (1936) The cultivatred races of Sorghum: VII+274 p.
Snowden J.D. (1955) The wild fodder Sorghums of the section Eu-Sorghum. Bot. Journ. Linn. Soc. 55: 191-260.
Spangler R.E. (2003) Taxonomy of Sarga, Sorghum and Vacoparis (Poaceae: Andropogoneae). Austral. Syst. Bot. 16(3): 279-299.
Tsvelev N.N. (1984) Grasses of the Soviet Union, part 1 and 2. A.A. Balkema, Rotterdam: XVI + 1196 p.