Modern corn,
Zea mays ssp. mays, is considered to be derived from
Zea mays ssp, parviglumis, a wild grass native to southern Mexico. About 9000 years ago, early farmers' generations of selective seed-saving finally resulted in something resembling modern maize. The rest is history-- the crop became the staple of Mesoamerican empires, fed European mouths after the Spanish conquest (or Spanish-Aztec War, if you prefer), and serves humankind today as the critical constituent of tortilla chips and a certain motor fuel additive.
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| Teosinte as a pseudo-ornamental. Its vigor was, perhaps, underestimated. |
But what business has a 21st-century gardener in growing the ancient
parviglumis? First, considering the grain as a potential food source: the hard exterior case surrounding the kernel necessitates a good bit of processing, and the yield, is, of course, quite small. John Doebley and his lab have written excellent articles on teosinte
here; addressing teosinte's use as a food crop, Doebley writes of one of his experiments, "The yield [of edible grain] over all of my plot was 467 kg/ hectare." One
survey of farms in 16 nations, with yield data from 2013, reports average corn yield as 7239 kg/ hectare-- rendering the yield of teosinte simply pitiful by comparison (Lunik & Langemeier). This is a bit unfair, though-- pitting a wild grass against some of the most heavily-modified plants in agriculture-- so Doebley notes that teosinte's yield is "
is not too far off yields of 1000 to 2000 kg/hectare of early US open pollinated maize varieties (Troyer and Mascia 1999)." On the whole, though, no person should plant teosinte expecting any substantial amount of grain in return.
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| "Teosinte ear (Zea mays ssp mexicana) on the left, maize ear on the right, and ear of their F1 hybrid in the center." Photograph and caption by John Doebley; used with permission. |
Corn is not very high on any list of ornamental plants. But I can think of two cultivar groups that are used ornamentally-- the multi-colored "Indian corn" often sold as an autumn decoration, and the two or three varieties of variegated corn sold by specialty seed purveyors (the ornamental variegation being that of the leaves). Both maintain the general habit of modern maize, however-- a single tall stalk. This is advantageous for densely-planted fields, but in the wild, natural selection would never favor such an uncompromisingly compact, bolt-upright architecture. Teosinte emerges as modern corn does, with a single leader shoot, but eventually issues side shoots from the base, resulting in much fuller grassy clump than would otherwise be expected from corn-- and ornamentally speaking, a nice clump is preferable to a tall, ramrod-straight stem.
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| Secondary growths begin to emerge from the base of teosinte. |
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| "Zea mays ssp. parviglumis plants growing in a ravine near Teloloapan in the Balsas river drainage, Guererro, Mexico." Photo by Hugh Iltis, caption by John Doebley. The tassels look quite nice here-- the lanky base is mercifully clothed in foliage. Maybe there's some potential... |
Is teosinte passable as an ornamental, then? No doubt most would consider it more ornamental than modern corn-- but that is a pretty low standard, admittedly. The average gardener, I expect, would declare it to resemble an untidy and unproductive patch of corn, curiously located in a flower bed rather than in a vegetable garden. The novelty of having such a historic plant-- one quite central to agriculture, genetically speaking, yet obscure in itself-- makes it worth having, in my view, even when it looks like johnson grass that's invaded the rose border. Hopefully, when day length shortens, my own patch will oblige me with flowers and seed.
