Zea mays |
Zea diploperennis |
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corn, cultivated corn |
diploperennial teosinte |
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Habit | Plants annual. | Plants perennial; rhizomatous, rhizomes to 15 cm, internodes 0.2-0.6 cm, often forming scaly, tuberous short shoots 1-2 cm thick. | ||||||||||||
Culms | (0.5)1-3(6) m tall, (0.5)1-5 cm thick. |
1-3.5 m tall, (1)2-3 cm thick, solitary or in large clumps. |
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Blades | mostly 30-90 cm long, 2.5-12 cm wide. |
usually to 40 cm long, 4-5.5 cm wide, linear-lanceolate. |
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Caryopses | concealed in fruitcases (wild taxa) or exposed (domesticated taxon); fruitcases of wild taxa distichous, triangular in side view; domesticated taxon without fruitcases, glumes reduced and shallow or collapsed and embedded in the rachis. |
concealed by the lower glumes. |
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Pistillate | inflorescences rames or spikes, usually shortly pedunculate (sometimes sessile), solitary, 4-30(40) cm long, (0.5)1-10 cm thick, with 2 or more rows of paired spikelets, hence the spikelets 4 or more ranked, rarely terminating in an unbranched staminate inflorescence. |
peduncles (1)2-4(5) per node, 5-25(52) cm, the 3-5 longer peduncles extending far beyond the subtending leaf sheaths, each peduncle with 1(2) pistillate rames; pistillate rames 5-10 cm long, 4-5 mm thick, distichous, with 5-10 solitary spikelets, frequently not enclosed in a leaf sheath; fruitcases trapezoidal in side view, 6-9 mm on the long side, 2.5-4.5 mm on the short side, 4-5 mm in diameter. |
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Staminate | panicles 10-25+ cm, with 1-60(235) branches, internodes 1.5-8.2 mm; spikelets 9-14 mm long, 2.5-5 mm wide; lower glumes rounded dorsally, flexible, translucent, papery, loosely enclosing the upper glumes, the 2 lateral veins subequal to the others, not winged. |
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Terminal | staminate panicles 6-18 cm, with 2-15 branches; branches 6-15 cm, erect to divergent, internodes 2-6 mm; spikelets 8.5-11.5 mm long, about 3 mm wide, densely imbricate; lower glumes flat dorsally, stiff, not translucent, margins tightly enclosing the upper glumes, the 2 principal sublateral veins prominently keeled and apically winged. |
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2n | = 20. |
= 20. |
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Zea mays |
Zea diploperennis |
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Distribution |
AL; AR; AZ; CA; CO; CT; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; NE; NH; NJ; NM; NV; NY; OH; OR; PA; RI; SC; TN; TX; UT; VA; VT; WA; WI; WV; WY; PR; ON; QC; Virgin Islands
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Discussion | Of the five subspecies of Zea mays, only the domesticated subspecies, Z. mays subsp. mays, is widely grown outside of research programs. Three wild subspecies are treated here, albeit briefly, because of their importance as genetic resources for Z. mays subsp. mays. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Zea diploperennis, although locally abundant, is rare in the wild, being known only from a few populations in the Sierra de Manantlan, Jalisco, Mexico. It grows at elevations of 1400-2400 m, sometimes forming large clones or extensive colonies in old maize fields and on the edges of oak-pine cloud forests. It is grown for genetic research and plant breeding in many countries and occasionally as an ornamental plant in warmer parts of the contiguous United States. It hybridizes infrequently with Z. mays subsp. mays in its native range. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 25, p. 701. | FNA vol. 25, p. 699. | ||||||||||||
Parent taxa | Poaceae > subfam. Panicoideae > tribe Andropogoneae > Zea | Poaceae > subfam. Panicoideae > tribe Andropogoneae > Zea | ||||||||||||
Sibling taxa | ||||||||||||||
Subordinate taxa | ||||||||||||||
Name authority | L. | H.H. litis, Doebley & R. Guzman | ||||||||||||
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