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23. Poaceae Tribe CYNODONTEAE
虎尾草族 hu wei cao zu
Authors: Bi-xing Sun, Shou-liang Chen, Zhen-lan Wu & Sylvia M. Phillips
Annual or perennial herbs. Leaf blades linear to ovate; ligule a short membrane with ciliate or ciliolate margin. Inflorescence composed of racemes; racemes solitary, digitate or scattered along an axis, tough, unilateral (bilateral and axis fragile in Lepturus), persistent, or sometimes racemes very short, contracted into a cylindrical spikelike inflorescence and falling entire from main axis, or spikelets borne directly on main axis. Spikelets with 1 fertile floret, with or without additional sterile florets, disarticulating above glumes but not between florets or falling entire; glumes herbaceous, 1–3-veined (5–12-veined in Lepturus), shorter than floret or exceeding and enclosing it, sometimes lower glume absent; lemma membranous to leathery, keeled or rounded, 1–3-veined, lateral veins near margins and often ciliate, apex entire or 2–3(–5)-lobed, awned or awnless. Caryopsis sometimes with free pericarp. Leaf anatomy: Kranz PS type; microhairs short and stout. x = 9, 10.
About 60 genera: throughout the tropics and subtropics, extending into North America; 12 genera (three introduced) and 27 species (six introduced) in China.
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| 1 |
Spikelets sunk in cavities of rachis; rachis fragile; inflorescence a single bilateral raceme. |
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141 Lepturus |
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Spikelets not in cavities; rachis tough; inflorescence not a single bilateral raceme |
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(2) |
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| 2 (1) |
Inflorescences unisexual, plant monoecious or dioecious; female inflorescence a tough globular burr in inflated upper leaf sheaths. |
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149 Buchloe |
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Inflorescences bisexual, all alike |
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(3) |
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| 3 (2) |
Inflorescence cylindrical; racemes very short, borne along central axis, deciduous, or deciduous spikelets borne singly |
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(4) |
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Inflorescence not cylindrical; racemes digitate, scattered or solitary, persistent or rarely deciduous |
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(6) |
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| 4 (3) |
Spikelets with long flexuous awns. |
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152 Perotis |
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Spikelets awnless or mucronate |
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(5) |
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| 5 (4) |
Spikelets 2 or more on short racemelets; glume with rows of hooked spines. |
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150 Tragus |
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Spikelets borne singly on the central axis; glume smooth, glossy. |
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151 Zoysia |
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| 6 (3) |
Racemes borne along an axis |
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(7) |
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Racemes digitate, subdigitate or solitary |
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(8) |
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| 7 (6) |
Lemma 3-awned; sterile floret and rachilla extension present. |
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148 Bouteloua |
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Lemma acute; sterile floret and rachilla extension absent. |
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147 Spartina |
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| 8 (6) |
Fertile floret solitary |
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(9) |
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Fertile floret accompanied by male or sterile florets |
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(10) |
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| 9 (8) |
Raceme solitary; glumes longer than and enclosing floret. |
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145 Microchloa |
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Racemes digitate; glumes shorter than the exposed floret. |
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146 Cynodon |
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| 10 (8) |
Spikelets dark brown; upper glume with stout subapical awn. |
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144 Eustachys |
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Spikelets pallid or purplish; upper glume at most with fine mucro |
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(11) |
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| 11 (10) |
Lemma keeled, caryopsis subterete. |
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142 Chloris |
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Lemma back flat, caryopsis dorsally compressed. |
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143 Enteropogon |
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List of lower taxa
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