The taxonomy of rice (Oryza spp.)
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The taxonomy of rice (Oryza spp.) |
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2n |
Genome |
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24 |
GG |
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24 |
GG |
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24 |
GG |
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48 |
HHJJ |
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48 |
HHJJ |
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48 |
HHKK |
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24 |
FF |
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48 |
CCDD |
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24, 48 |
CC |
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48 |
CCDD |
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48 |
CCDD |
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48 |
BBCC |
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24, 48 |
CC |
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24, 48 |
BB, BBCC |
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24 |
CC |
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24 |
EE |
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24 |
AA |
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24 |
AA |
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24 |
AA |
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24 |
AA |
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24 |
AA |
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24 |
AA |
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24 |
AA |
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24 |
AA |
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Key to wild species of rice (Oryza spp.)
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1a |
Spikelets <2mm long, nodes hairy |
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| 1b | Spikelets >2mm long, nodes usually not hairy |  2 |
| 2a | Spikelets awnless, surface of lemma and palea granulate or with hooked hairs | 3 |
| 2b | Spikelets with awns or short apiculus at the tip of lemma, not granulate | 5 |
| 3a | Surface of lemma and palea with hooked hairs | O. neocaledonica |
| 3b | Surface of lemma and palea granulate | 4 |
| 4a | Spikelets slender, >6.5 mm long | O. meyeriana |
| 4b | Spikelets more or less rounded, <6.5 mm long | O. granulata |
| 5a | Sterile lemma subulate or setaceous | 6 |
| 5b | Sterile lemma linear or linear-lanceolate | 8 |
| 6a | Annual, small plants, spikelets <1.6 mm wide | O. brachyantha |
| 6b | Perennial, large plants, spikelets > 1.8 mm wide | 7 |
| 7a | Spikelet 7.6-12.7 mm long, sterile lemma 0.3-0.8 times as long as spikelets | O. ridleyi |
| 7b | Spikelets about 7-8.2 mm long, sterile lemma 0.8-1.3 times as long as spikelets | O. longiglumis |
| 8a | Spikelets with comma-shaped rachilla, oblique articulation, mucronate lemma | 9 |
| 8b | Spikelets with straight rachilla, horizontal or slightly oblique articulation, non-mucronate lemma | 14 |
| 9a | Ligule of lower leaves usually <10 mm long, tip rounded or truncate, panicle rarely has secondary branching | O. barthii |
| 9b | Ligule of lower leaves >10 mm long, tip acute or two-cleft, panicle usually has secondary branching | 10 |
| 10a | Annual, anthers usually <2.5 mm long | 11 |
| 10b | Perennial, anthers usually >3 mm long | 12 |
| 11a | Spikelets slender, usually <2mm wide, base of awns thick | O. meridionalis |
| 11b | Spikelets broad, usually >2 mm wide, base of awns not thick | O. nivara |
| 12a | Rhizomatous habit | O. longistaminata |
| 12b | Plant usually not rhizomatous | 13 |
| 13a | Plants with brittle culm near the base, spikelets 6.6-11 long, anthers occupying 2/3 or 3/4 of the spikelets | O. glumaepatula |
| 13b | Plants with high nodal tillering, spikelets 4.5-10.6 long, anthers occupying the entire length of the spikelets | O. rufipogon |
| 14a | Rhizomatous, axis of the panicles hispid-scabrous towards the tip | O. australiensis |
| 14b | Sometimes rhizomatous, axis of the panicle branches glabrous or hairy | 15 |
| 15a | Plants large, leaf blades >2 cm wide | 16 |
| 15b | Plants relatively small, leaf blades <2 cm wide | 18 |
| 16a | Sterile lemma almost as long as the fertile lemma | O. grandiglumis |
| 16b | Sterile lemma much shorter than the fertile lemma | 17 |
| 17a | Leaf blades <5 cm wide, spikelets <7 mm long | O. latifolia |
| 17b | Leaf blades >5 cm wide, spikelets >7 mm long | O. alta |
| 18a | Panicle base usually with 2 or more (often 3-5) equally long branches | 19 |
| 18b | Panicle base lacking whorl of branches, usually 1-2 branches | 20 |
| 19a | Tufted habit, awns usually >2 cm long | O. punctata |
| 19b | Usually shortly rhizomatous, awns <2 cm or absent | O. officinalis |
| 20a | Rhizomatous, open panicles, spikelets usually >6 mm long | O. rhizomatis |
| 20b | Non-rhizomatous, semi-open panicles, spikelet <6 mm long | 21 |
| 21a | Tufted habit, spikelets usually >5 mm long | O. eichingeri |
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21b |
Creeping habit, spikelets usually <5 mm long |
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Related genera in the tribe Oryzeae
| Genus | No. of species | Distribution | 2n |
| Chikusiochloa | 3 | China, Japan (t) | 24 |
| Hygroryza | 1 | Asia (t + T) | 24 |
| Leersia | 17 | Worldwide (t + T) | 48, 60, 96 |
| Luziola | 11 | North and south America (t + T) | 24 |
| Maltebrunia | 5 | Tropical and Southern Africa (T) | Unknown |
| Oryza | 24 | Pan-tropical (T) | 24, 48 |
| Porteresia | 1 | South Asia (T) | 48 |
| Prosphytochloa | 1 | Southern Africa (t) | Unknown |
| Potamophila | 1 | Australia (t + T) | 24 |
| Rhynchoryza | 1 | South America (t) | 24 |
| Zizania | 3 | Europe, Asia, N. America (t + T) | 30, 34 |
| Zizaniopsis | 5 | North and South America (t + T) | 24 |
| T = tropical area, t = temperate area | |||
