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Vascular Plants of California
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Cenchrus incertus

Higher Taxonomy
Family: Poaceae (Gramineae)View DescriptionDichotomous Key
Habit: Annual to woody perennial herb; roots generally fibrous. Stem: generally round, hollow; nodes swollen, solid. Leaf: alternate, 2-ranked, generally linear, parallel-veined; sheath generally open; ligule membranous or hairy, at blade base. Inflorescence: various (of generally many spikelets). Spikelet: glumes generally 2; florets (lemma, palea, flower) 1--many; lemma generally membranous, sometimes glume-like; palea generally +- transparent, +- enclosed by lemma. Flower: generally bisexual, minute; perianth vestigial; stamens generally 3; stigmas generally 2, generally plumose. Fruit: grain, sometimes achene- or utricle-like.
Genera In Family: 650--900 genera; +- 10550 species: worldwide; greatest economic importance of any family (wheat, rice, maize, millet, sorghum, sugar cane, forage crops, ornamental, weeds; thatching, weaving, building materials). Note: Generally wind-pollinated. Achnatherum, Ampelodesmos, Hesperostipa, Nassella, Piptatherum, Piptochaetium, Ptilagrostis moved to Stipa; Elytrigia, Leymus, Pascopyrum, Pseudoroegneria, Taeniatherum to Elymus; Hierochloe to Anthoxanthum; Lolium, Vulpia to Festuca; Lycurus to Muhlenbergia; Monanthochloe to Distichlis; Pleuraphis to Hilaria; Rhynchelytrum to Melinis. The following taxa (in genera not included here), recorded in California from historical collections or reported in literature, are extirpated, lacking vouchers, or not considered naturalized: Acrachne racemosa (Roth) Ohwi, Allolepis texana (Vasey) Soderstr. & H.F. Decker, Amphibromus nervosus (Hook. f.) Baill., Axonopus affinis Chase, Axonopus fissifolius (Raddi) Kuhlm., Coix lacryma-jobi L., Cutandia memphitica (Spreng.) K. Richt., Dinebra retroflexa (Vahl) Panz., Eremochloa ciliaris (L.) Merr., Eustachys distichophylla (Lag.) Nees, Gaudinia fragilis (L.) P. Beauv., Miscanthus sinensis Andersson, Neyraudia arundinacea (L.) Henrard, Phyllostachys aurea Rivière & C. Rivière, Phyllostachys bambusoides Siebold & Zuccarini, Rottboellia cochinchinensis (Lour.) Clayton, Schedonnardus paniculatus (Nutt.) Branner & Coville, Schizachyrium cirratum (Hack.) Wooton & Standl., Schizachyrium scoparium (Michx.) Nash, Themeda quadrivalvis (L.) Kuntze, Thysanolaena latifolia (Hornem.) Honda, Tribolium obliterum (Hemsl.) Renvoize, Zea mays L., Zizania palustris L. var. interior (Fassett) Dore, Zoysia japonica Steud. Paspalum pubiflorum E. Fourn., Paspalum quadrifarium Lam., are now reported for southern California (J Bot Res Inst Texas 4:761--770). See Glossary p. 30 for illustrations of general family characteristics.
eFlora Treatment Author: James P. Smith, Jr., except as noted
Scientific Editor: James P. Smith, Jr., J. Travis Columbus, Dieter H. Wilken.
Genus: CenchrusView DescriptionDichotomous Key

Common Name: SANDBUR
Habit: Annual, perennial herb. Stem: 5--100(200) cm, erect or decumbent, generally bent; nodes and internodes generally glabrous; internode solid to spongy. Leaf: basal and cauline; sheath generally smooth; ligule short-hairy or membranous, ciliate; blade flat or folded, margins generally cartilaginous. Inflorescence: panicle-like, central axis wavy, with reduced branches bearing burs, each consisting of 1--4(8) +- sessile spikelets generally enclosed by an involucre of flattened or cylindric bristle- or spine-like, +- fused bracts, these generally forming an inner and outer set; involucre and enclosed spikelets falling as 1 unit. Spikelet: +- dorsally compressed; glumes strongly unequal, ovate, lower 1-veined, upper +- = florets, 3--9-veined; florets 2, lower floret sterile or staminate, lemma generally 5-veined, palea generally present, upper floret fertile, lemma thick, +- hard, palea +- = lemma; anthers 3.
Species In Genus: +- 16 species: warm temperate America, Africa, southern Asia. Etymology: (Uncertain. Greek: for millet or Latin for a precious stone) Note: Cenchrus ciliaris L. is now treated as Pennisetum ciliare (L.) Link.
eFlora Treatment Author: James P. Smith, Jr.
Reference: Stieber & Wipff 2003 FNANM 25:529--535
Unabridged Reference: Delisle 1963 Iowa State J Sci 37:259--351
Cenchrus incertus M.A. Curtis
Habit: Annual or short-lived perennial herb. Stem: decumbent, 1--5(10) dm. Leaf: sheath 2.5--7 cm; ligule 0.5--1.5 mm; blade 3--28 cm, (1)2.5--7 mm wide, upper surface glabrous. Inflorescence: 2--5(8.5) cm; inner bracts 8--40, fused at least 1/2, forming cup. Spikelet: 3.5--5.9 mm, ovate, glabrous; lower glume 1--3.5 mm, upper glume 3--5 mm; lower floret staminate, lemma 1--3.5 mm, 5--7-veined; upper lemma 3.5--5 mm. Chromosomes: 2n=(32)34.
Ecology: Disturbed areas; Elevation: 10--1500 m. Bioregional Distribution: GV, SCo, PR, DMoj (near Daggett), DSon; Distribution Outside California: Washington, Oregon; native to southern United States, Mexico, Central America, South America. Flowering Time: Jul--Sep
Synonyms: Cenchrus pauciflorus Benth.; Cenchrus spinifex Cav.
Jepson eFlora Author: James P. Smith, Jr.
Reference: Stieber & Wipff 2003 FNANM 25:529--535
Index of California Plant Names (ICPN; linked via the Jepson Online Interchange)
Noxious Weed listed by CDFA
Weed listed by Cal-IPC

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Citation for this treatment: James P. Smith, Jr. 2012, Cenchrus incertus, in Jepson Flora Project (eds.) Jepson eFlora, /eflora/eflora_display.php?tid=18552, accessed on August 08, 2020.

Citation for the whole project: Jepson Flora Project (eds.) 2020, Jepson eFlora,, accessed on August 08, 2020.

Cenchrus incertus
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© 2008 Steve Matson
Cenchrus incertus
click for enlargement
© 2008 Steve Matson
Cenchrus incertus
click for enlargement
© 2008 Steve Matson
Cenchrus incertus
click for enlargement
© 2008 Steve Matson

More photos of Cenchrus incertus in CalPhotos

Geographic subdivisions for Cenchrus incertus:
GV, SCo, PR, DMoj (near Daggett), DSon
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map of distribution 1
(Note: any qualifiers in the taxon distribution description, such as 'northern', 'southern', 'adjacent' etc., are not reflected in the map above, and in some cases indication of a taxon in a subdivision is based on a single collection or author-verified occurence).


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Data provided by the participants of the  Consortium of California Herbaria.
View all CCH records
All markers link to CCH specimen records. The original determination is shown in the popup window.
Blue markers indicate specimens that map to one of the expected Jepson geographic subdivisions (see left map). Purple markers indicate specimens collected from a garden, greenhouse, or other non-wild location.
Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues.

CCH collections by month

Duplicates counted once; synonyms included.
Species do not include records of infraspecific taxa, if there are more than 1 infraspecific taxon in CA.
Blue line denotes eFlora flowering time (fruiting time in some monocot genera).