All Floras      Advanced Search
FOC Vol. 22 Page 499 Login | eFloras Home | Help
FOC | Family List | FOC Vol. 22 | Poaceae

24. Poaceae Tribe PANICEAE

黍族 shu zu

Authors: Shou-liang Chen, Sylvia M. Phillips & Stephen A. Renvoize

Perennial or annual. Leaf blades usually linear or lanceolate; ligule membranous, a line of hairs, or a short membrane with ciliate fringe (rarely absent in some Echinochloa). Inflorescence variable, an open to spikelike panicle or composed of unilateral racemes, these digitate or spread along a cental axis; spikelets single, paired or clustered, sometimes supported by spines or bristles. Spikelets all alike (sexes separate in Spinifex and Thuarea), florets 2, without a rachilla extension, lower floret staminate or barren, upper floret bisexual, spikelets dorsally or infrequently lightly laterally compressed, falling entire, usually awnless; glumes membranous or herbaceous, lower glume usually shorter than the spikelet and sometimes very small or rudimentary, upper glume often as long as the spikelet; lower lemma usually as long as the spikelet and resembling the upper glume, with or without a palea; upper floret commonly indurated, tightly enclosing the caryopsis, lemma margins narrow and inrolled or broad and hyaline. Caryopsis with a large embryo 1/3–1/2 its length, hilum punctiform (rarely linear in Acroceras, Oplismenus, and some Panicum). Leaf anatomy: mixed, including non-Kranz, Kranz MS, and Kranz PS types. x = 9, occasionally 10 (rarely other numbers reported).

About 100 genera and ca. 2000 species: tropical and subtropical regions of the world, extending into temperate regions especially in North America; 27 genera (one endemic, two introduced) and 145 species (16 endemic, 12 introduced) in China.

The Paniceae are a distinctive tribe on account of the uniform pattern of deciduous, 2-flowered spikelets with a staminate or barren lower floret and an indurated, fertile upper floret enclosing the caryopsis.

1 Plants dioecious; female inflorescence a large globose spiny head.   179 Spinifex
+ Plants bisexual; inflorescence not as above   (2)
2 (1) Spikelets of 2 kinds, the upper staminate portion of the raceme folding over 1–2 bisexual spikelets.   168 Thuarea
+ Spikelets all alike   (3)
3 (2) Spikelets (at least some of them) subtended by bristles or a spiny involucre; or raceme rachis prolonged into a bristle or short point beyond the uppermost spikelet   (4)
+ Spikelets not subtended by bristles; or raceme rachis terminating in a spikelet   (9)
4 (3) Inflorescence of racemes, only the uppermost spikelet of each raceme subtended by a bristle or short (often inconspicuous) point   (5)
+ Inflorescence paniculate, often spikelike, all or many of the spikelets subtended by bristles or a spiny involucre   (7)
5 (4) Racemes ending in a long bristle; upper glume acuminate-aristate.   176 Pseudoraphis
+ Racemes ending in an inconspicuous point; upper glume not awned   (6)
6 (5) Racemes very short, sunk in pockets on the broad or thick inflorescence axis; upper lemma smooth.   173 Stenotaphrum
+ Racemes not sunk in pockets, inflorescence axis slender; upper lemma rugose or granulate.   172 Paspalidium
7 (4) Bristles persisting on the axis after the spikelets have fallen.   171 Setaria
+ Bristles or spines falling as involucres around the spikelets   (8)
8 (7) Involucral bristles slender, free to the base.   177 Pennisetum
+ Involucral bristles and spines flattened and connate below, forming a cup.   178 Cenchrus
9 (3) Inflorescence an open, contracted or spikelike panicle; pedicels usually all slender and distinct   (10)
+ Inflorescence of unilateral racemes; spikelets usually single or paired; pedicels often very short, at least for one spikelet of a pair   (18)
10 (9) Spikelets laterally compressed   (11)
+ Spikelets dorsally compressed   (13)
11 (10) Glumes keeled; upper floret with wings or scars at the base.   155 Ichnanthus
+ Glumes not keeled; upper floret without basal wings or scars   (12)
12 (11) Lower lemma entire, awnless; upper lemma gibbously semiorbicular with a little greenish crest near the apex.   160 Cyrtococcum
+ Lower lemma bilobed or shortly awned; upper lemma elliptic, not crested.   174 Melinis
13 (10) Panicle spikelike   (14)
+ Panicle open, the spikelets evenly spaced or appressed along the primary branches   (15)
14 (13) Upper glume gibbous; culms hollow.   158 Sacciolepis
+ Upper glume not gibbous; culms filled with aerenchyma.   157 Hymenachne
15 (13) Upper glume as long as or only slightly shorter than the spikelet   (16)
+ Upper glume 2/3 spikelet length or less   (17)
16 (15) Margins of upper palea free toward apex; trailing semi-aquatic perennial   157 Hymenachne
+ Margins of upper palea clasped by upper lemma along whole length.   156 Panicum
17 (15) Upper glume 1/2–2/3 spikelet length, 3–5-veined; spikelets on short appressed secondary racemelets   159 Ottochloa
+ Upper glume very small, usually veinless; spikelets on long capillary pedicels   175 Digitaria
18 (9) Apex of upper lemma awned, crested or with a tuft of setae   (19)
+ Apex of upper lemma not as above   (21)
19 (18) Upper lemma awned; upper glume ciliate on the margins.   164 Alloteropsis
+ Upper lemma apex crested or with a tuft of setae; upper glume glabrous   (20)
20 (19) Apex of upper lemma with a tuft of short setae.   161 Setiacis
+ Apex of upper lemma with a little green crest.   162 Acroceras
21 (18) Spikelets laterally compressed or glumes awned; leaf blades lanceolate to ovate; trailing forest grasses   (22)
+ Spikelets dorsally compressed; lower glume awnless   (23)
22 (21) Glumes not awned, upper glume armed with hooked bristles at maturity.   153 Pseudechinolaena
+ Glumes awned, the awns often sticky.   154 Oplismenus
23 (21) Spikelets densely packed in 4 rows or congested into clusters; apex of upper palea reflexed   163 Echinochloa
+ Spikelets mostly in 1 or 2 rows; apex of upper palea tucked in   (24)
24 (23) Spikelets supported on a basal globular beadlike swelling; lower glume vestigial.   167 Eriochloa
+ Spikelets without a basal beadlike swelling (rarely with a barrel-shaped basal stipe, but then lower glume well developed)   (25)
25 (24) Upper lemma cartilaginous to papery, the margins broad, flat and hyaline, covering much of the palea   175 Digitaria
+ Upper lemma coriaceous to bony with inrolled or flat margins exposing much of the palea (if texture thinner then margins inrolled)   (26)
26 (25) Lower glume present   (27)
+ Lower glume absent   (28)
27 (26) Upper lemma acute, obtuse or briefly mucronulate, subequaling spikelet; spikelets plumply elliptic, acute or obtuse; back of upper lemma facing away from rachis.   165 Brachiaria
+ Upper glume clearly mucronate, shorter than spikelet; spikelets plano-convex, acuminate; back of upper lemma lying against rachis.   166 Urochloa
28 (26) Back of upper lemma lying against rachis; spikelets strongly plano-convex, often orbicular.   169 Paspalum
+ Back of upper lemma facing away from rachis; spikelets thinly biconvex, oblong-elliptic.   170 Axonopus

  • List of lower taxa


    Related Objects  
  • FOC22_24_Paniceae.pdf
  • PDF

  • Flora of China @
    Browse by
    Advanced Search

    Flora of China Home




     |  eFlora Home |  People Search  |  Help  |  ActKey  |  Hu Cards  |  Glossary  |