Cyperus difformis

Species:Cyperus difformis Linnaeus
Common Name:Variable Flatsedge; Small Flower Flatsedge
Associated Ecological Communities:**
Growth Habit:Herb
USDA Symbol:**
Plant Notes:Variable Flatsedge is an introduced herbaceous annual in the Sedge family (Cyperaceae). It is native from southern Europe south through Africa and east through Asia to Australia. In Alabama it can be found at scattered locations statewide. Variable Flatsedge grows in disturbed wet habitats such as lakes and ponds, roadside ditches, and storm drains. It is a clump-forming annual with a fibrous root system. Each clump has 1-15 erect stems that are 3-angled, glabrous, and 3-12 inches in height. There are 2-7 flat, linear, glabrous leaves. Flowers are produced in spikes that are arranged in dense, sessile, irregular heads. The heads are subtended by 2-4 bracts with minute teeth along their margins. The longest bract of the inflorescence appears as a continuation of culm and the other bracts are spreading. Spikelets are greenish-brown to purple-brown in color. The fruit is a light brown obovoid to elliptical achene. The surface of the achene is finely reticulate and papillose.—A. Diamond
Taxonomic Notes:**
Status:Not Native, OBL (NWI)
Specimen: View specimen details in the Alabama Herbarium Consortium Specimen Database

** Not applicable or data not available.


FamilyCYPERACEAE - Sedge family
Genus Cyperus
Species Cyperus difformis Linnaeus - Variable Flatsedge; Small Flower Flatsedge


Citation CYPERUS DIFFORMIS Linnaeus, Cent. Pl. 2: 6. 1756.
Basionym: **
Type: INDIA: Without data (lectotype: LINN 70.10). Lectotypified by G. C. Tucker, Syst. Bot. Monogr. 43: 50. 1994.

** Not applicable or data not available.


SynonymFull CitationBasionymType
Cyperus complanatus Cyperus complanatus Forsskål, Fl. Aegypt.-Arab. 14. 1775.  
Cyperus difformis var. breviglobosus Cyperus difformis Linnaeus, var. breviglobosus Kükenthal, in Engler, Pflanzenr. 4(Heft 101): 240. 1936.  
Cyperus difformis var. congestus Cyperus difformis Linnaeus, var. congestus E. G. Camus, Notul. Syst. (Paris) 1: 291. 1910.  
Cyperus difformis var. pumilus Cyperus difformis Linnaeus, var. pumilus Kuntze, Revis. Gen. Pl. 2: 749. 1891.  
Cyperus difformis var. subdecompositus Cyperus difformis Linnaeus, var. subdecompositus Kükenthal, in Engler, Pflanzenr. 4(Heft 101): 240. 1936.  
Cyperus goeringii Cyperus goeringii Steudel, Syn. Pl. Glumac. 2: 24. 1854. INDONESIA: Java:
Cyperus holoschoenoides Cyperus holoschoenoides Jan ex Schultes, Mant. 2: 111. 1824.  
Cyperus lateriflorus Cyperus lateriflorus Torrey, in Emory, Rep. U.S. Mex. Bound. 2(1): 226. 1858 ("1859"). MEXICO: Sonora: E of Santa Cruz, s.d., Wright 1950 (holotype: NY; isotypes: GH, YU).
Cyperus oryzetorum Cyperus oryzetorum Steudel, Syn. Pl. Glumac. 2: 24. 1854. U.S.S.R.: Azerbaijan: Lenkoran,
Cyperus protractus Cyperus protractus Link, Hort. Berol. 1: 305. 1827, non Delile 1813-1814.  
Cyperus subrotundus Cyperus subrotundus Llanos, Fragm. Pl. Filip. 14. 1851.  

Specimens and Distribution

This species has been reported in the following counties by the herbaria listed. An overview of the individual specimens are provided in the table that follows. Click on the accession number to view details; click on column headers to sort; choose a county or herbaria to filter the specimen data.

Counties included on distribution map: Colbert, Houston, Limestone, Marshall, Mobile

Counties represented by specimen data listed below:

Herbaria represented by specimen data listed below: AUA, JSU, TROY, UNAF, UWAL

Range of years during which specimens were collected: -

Barcode / Accession No. County Coll. Date Collector &
Collection No.
Herbarium &
Herbarium Name Used
JSU111899 Marshall 19 Oct 1992 D. D. Spaulding
Cyperus difformis Linnaeus
TROY000043880 Houston 03 Dec 2015 Alvin R. Diamond
Cyperus difformis Linnaeus
UWAL0035801 Mobile 04 Aug 2013 Horne, Howard E.
Cyperus difformis Linnaeus
TROY000036213 Houston 09 Dec 2012 Alvin R. Diamond
Cyperus difformis Linnaeus
AUA000021015 Limestone 22 SEP 1970 KRAL, ROBERT
UWAL0033100 Houston 03 Dec 2015 Diamond, Alvin R.
Cyperus difformis Linnaeus
UNAF0001797 Colbert 05 Jul 2010 Webb, David H.
Cyperus difformis Linnaeus
UWAL0013529 Houston 09 Dec 2012 Diamond, Alvin R.
Cyperus difformis Linnaeus
TROY000028375 Mobile 12 Sep 1995 Richard Carter
Cyperus difformis Linnaeus
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