3. Setaria italica (L. ) Beauv. [syn.: S. viridis subsp. italica (L.) Briquet] (cult.?) – A common birdseed component, seen every year as an ephemeral alien on tips, rubbish dumps, by motorways or as an urban weed. It was apparently first collected in Leuven in 1856, without further details.
Setaria italica is extremely variable (see Hubbard 1915, Scholz 1961, Rao 1987) and many forms are hardly distinguishable from S. viridis (very likely its ancestral species). Panicles can be very large, lobbed and nodding from near the base (under the weight of the ripe caryopses) as well as short and thick. The smooth, shining and persisting upper lemmas are perhaps the only reliable diacritic feature to distinguish Setaria italica with certainty from S. viridis. It is therefore maybe better regarded as a subspecies of the latter.
Selected literature:
Hubbard F.T. (1915) A taxonomic study of Setaria italica and its immediate allies. Amer. J. Bot. 2: 169-198.
Rao K.E.P. (1987) Infraspecific variation and systematics of cultivated Setaria italica, Foxtail Millet (Poaceae). Econ. Bot. 41: 108-116.
Scholz H. (1964) Zur Gramineeflora Mitteleuropas II. Ber. Dtsch. Bot. Ges. 77: 145-160.