Dichromena, Dulchium, and Eleocharis of Arkansas:

 an annotated list

 Revised October 1, 2012.

This page provides a list of all Arkansas Dichromena, Dulchium, and Eleocharis sedges. I am adding brief hints for the field identification of each taxon. Taxonomic problems exist within the genus Eleocharis in Arkansas and elsewhere that are beyond the scope of this treatment; they have been discussed, but certainly not settled. Note: I often abbreviate counties with unique first-four-letter codes such as Baxt for Baxter, without a period.

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(Taxonomy of species marked with an asterisk * matches the "Checklist of the Vascular Plants of Arkansas", a document of the Arkansas Flora Committee, version 9.0, January 18, 2003).

(Green text designates species recognized in the draft "Checklist of the Vascular Plants of Arkansas", a document internal to the Arkansas Flora Committee, January 18, 2003, to be released in October of this year.

Blue text designates "possible additions" to the flora of Arkansas, not currently represented by specimens.
Red text designates excluded species, perhaps attributed to but not expected in Arkansas by this author.)

Dichromena of Arkansas

Dichromena colorata (L.) A. S. Hitchc.

See the discussion * Rhynchospora colorata (L.) A. S. Hitchc. This is a synonym of that species, treated as Dichromena by Smith (1994) and other authors. I have currently (March 2003) seen specimens at LSU (Demaree 19264) and UCAC (Logan 101) from Brad Co. Smith (1994) heard of a report from Litt Co.

Dulchium of Arkansas

Dulchium arundinaceum (L.) Britt.

Smith (1994) used this name, and reported (1988, and pers. commun. 1993 nine other occurrences. I have yet to review specimens.

 

Eleocharis of Arkansas

A quick review of the genus Eleocharis in Arkansas reminds me of my study of Arkansas Carex sedges. Edwin B. Smith (1988) reported six of sixteen Arkansas Eleocharis from six or fewer counties. One has to remember that Smith tended to lump sedge species. The Arkansas Flora Committee recognizes 23 taxa (unpublished data, subject to change). Yet Kartesz & Meachum (1999) report 48 taxa in Arkansas and surrounding states, many of which are not addressed below. A thorough search of Arkansas for Eleocharis would surely result in numerous state records (from herbarium and/or field searches)! Many county records could be found, I'm sure!

Eleocharis acicularis (L.) R. & S.

Smith (1988) reported Least Spikerush from 11 counties, mostly in the northwestern half of Arkansas. Hyatt (1993) added Baxt Co. I have also seen specimens from Mill (Hooten 626 LTU) and Cleb (LSU) counties. This species occurs throughout North American north of Mexico (Kartesz & Meachum 1999). This species and E. tenuis var.

verrucosa

both can be recognized by their very fine, hairlike culms. Mature achenes are, unfortunately, required, to tell the two species apart!

 

E. acutangula

This species of Texas and/or Oklahoma (see Kartesz & Meachum 1999) is probably unlikely in Arkansas.

 

E. acutisquamata

This species of Texas and/or Oklahoma (see Kartesz & Meachum 1999) is probably unlikely in Arkansas.

 

Eleocharis albida Torr.

Smith (1994) listed this as a possible addition to the flora of Arkansas. It occurs in coastal plain states from Texas to Virginia (Kartesz & Meachum 1999). Radford (1968) reports it from "brackish sands and pools" of the outer coastal plain. Smith (pers. commun. 1991) probably considered it because of a report from East Carroll Parish in extreme northeast Louisiana (see Thomas & Allen 1993). Its most likely location for Arkansas would be in brackish areas associated with oil well pumping in Unio Co., or other sites with naturally saline soils.

 

Eleocharis atropurpurea (Retz.) J. K. Presl.

Purple Spike Rush, as this is known, occurs in states along the southeast Atlantic coast, and from Texas north in great plains states and other scattered states and provinces (Kartesz & Meachum 1999). Its status in Arkansas is uncertain; Smith (1994) did not address it. I did not find it in records from Yatskievych (1999), Diggs, et al. (1999), and Radford (1968). It needs further study in Arkansas, but apparently has been reported to the Arkansas Flora Committee. In Louisiana, it is konwn from only three parishes. Its distribution must be scattered generally within the region and it is highly likely in Arkansas; I've not seen a specimen.

 

Eleocharis baldwinii (Torr.) Chapm.

Smith (1988, 1994) considered Flatstem Spikerush a possible addition to the flora of Arkansas, most likely in Unio to Ashl cos. I have not seen a voucher, but it has apparently been reported to the Arkansas Flora Committee for Arkansas.

 

Eleocharis brittonii

This species occurs in Texas and/or gulf coastal states. It is not considered likely for Arkansas.

 

Eleocharis brittonii and E. cancellata

This species occurs in Texas and/or gulf coastal states. It is not considered likely for Arkansas.

 

Eleocharis cellulosa Torr.

Gulfcoast Spikerush is one of three Arkansas species of this genus with the spikelet nearly as wide as the stem; such species usually have unusually wide stems compared to other species in the genus. Smith (1988) reports it for Union Co. and I have seen specimens of R. Dale Thomas from there, housed at UCAC and LSU. In the field, also look for round stems which are not nodose-septate (appearing jointed, knotty, or with nodes).

 

Eleocharis compressa Sulliv.

Smith (1988) reported this for Carr, Fran, and Lawr counties adn the author has seen specimens from Baxt (UARK), Prai (VSC, probably Hyatt collection), and Sear (UARK). Perhaps it occurs throughout the Ozarks, or perhaps more frequently on the Salem and/or Springfield plateaus based on this and the Missouri distribution in Yatskievych (1999). He provides a good discussion of the species. I do not know the species well so have no current ID hints. I need to study the "var. compressa".

 

Eleocharis engelmannii Steud.

It appears that E. engelmannii and E. obtusa may be more appropriately lumped as E. ovata. The flora committee currently gives them recognition, although I question the wisdom of splitting them out. I plan further study. Yatskievych (1999) provides a good discussion of these "species". Smith (1988) reports it from several counties in the northern two thirds of Arkansas. The author has seen duplicates determined as this by Richard Carter (VSC) from Baxt and HotS cos. It is widespread and occurs in most of the U. S. (Kartesz & Meachum 1999).

 

Eleocharis equisetoides (Ell.) Torr.

Horsetail spikerush is easily recognized with "larger than normal" stems (for a spikerush) which have conspicuous joints (nodose-septate). Smith (1988) reports only Pula County. Kartesz & Meachum (1999) report it from the southeastern coastal plain states, with historic records north into Wisconsin through Arkansas and Missouri, and few scattered records in the eastern U. S. otherwise.

 

Eleocharis erythropoda Steud.

Redfoot Sedge occurs in much of the eastern U. S., but is absent in some southeastern states (Kartesz & Meachum 1999). Smith (1988, and pers. commun. 1993) reports 12 Arkansas counties. Hyatt has seen it from Faul (UCAC), Inde (UARK via Lyon College), Izar (VSC), and Prai (VSC) counties.

 

Eleocharis fallax Weatherby

This coastal plain taxon (Kartesz & Meachum 1999) is probably unlikely in Arkansas.

 

Eleocharis flavescens (Poir.) Urban including var. flavescens

Pale Spikerush may approach Arkansas, based on a Lincoln Parish report from Louisiana (Thomas & Allen 1993). The Arkansas Flora Committee has an Arkansas record which I've not reviewed yet (March 2003). Smith (pers. commun. 1993) noted it from Union Co. I have not checked out the varieties nor studied it in detail yet. I have annotated a Jeff County Arkansas specimen as APCR as this, but would be wise to revisit it.

 

Eleocharis geniculata Fern.

This taxon approaches Arkansas and may not be too surprising to find extant in the state!

 

Eleocharis intermedia Fern.

This taxon approaches Arkansas and may not be too surprising to find extant in the state!

 

Eleocharis lanceolata Fern.

This is a more clear segregate from E. ovata and E. obtusa than those two taxa are distinct from each other (see Yatskievych (1999)). Smith (1988, pers. commun. 1993) reports Daggerleaf Sedge for 32 Arkansas counties. Hyatt has recorded 12 counties in searches of APCR, LSU, LTU, UCAC, and with at least one recent collection. Apparently the species ranges (in the U. S.) from Texas, Oklahoma, and Arkansas to less frequently in Kansas, Missouri, and Tennessee (Kartesz & Meachum 1999).

 

Eleocharis macrostachya Britt.

MacGregor's (1977) atlas of the flora of the great plains apparently reported this species from Arkansas (Kartesz & Meachum 1999). See discussion under E. palustris.

 

Eleocharis microcarpa Torr.

Smith (1988, 1994) reported this species for Arkansas from Ashl, Cahl, and Drew counties. I have annotated Jeff (APCR) and Cahl (E. B. Smith 7890 LTU) specimens as Smallfruit Beaksedge.

 

Eleocharis montevidensis Kunth

I've annotated two specimens as this species, known commonly as Sand Spikesedge: E. B. Smith 3379 LSU (with ID by S. Galen Smith) and Tucker 16114. Both are from Litt Co.

 

Eleocharis olivacea Torr.

See Yatskievych (1999) for reasons to lump this with E. flavescens despite Kartesz & Meachum's (1999) recognition of this taxon. They list the range as nearly surrounding Arkansas from Texas through Louisiana to Mississippi, and to the north and east of Arkansas (not Missouri). I have no records of it in Arkansas. Smith (1988) does not index it or appear to mention it.

 

Eleocharis obtusa (Willd.) Schultes and Eleocharis ovata (Roth) Roemer & J. A. Schultes

It appears that E. engelmannii and E. obtusa may be more appropriately lumped as E. ovata. For about 2001, I was lumping the three under the latter name. Since the flora committee continues to recognize them as distinct, I'm trying to sort them out. See Yatskievych (1999) for details. Smith (1988, 1994) lumped the latter two under E. obtusa. E. obtusa is far more common in Arkansas than E. ovata but the details would need to be sorted out.

 

Eleocharis palustris R. & S.

See Yatskievych (1999) for a detailed discussion of the broad use of this name. I currently am following his lead, and at the same time trying to annotate things in such a way as to reflect the Arkansas Flora Committee's tentative recognition of E. macrostachya specimens in Arkansas. I have alot to learn about Eleocharis in general, and am developing a key (March 2003).

 

Eleocharis parvula (R. & S.) Link var. parvula

Smith (1988, pers. commun. 1993) reports this species from four Arkansas counties, including Union. It needs further study in Arkansas. Its apparently widespread in North America (Kartesz & Meachum 1999).

 

Eleocharis quadrangulata (Michx.) R. & S.

Scattered records exist for this species in the western three-fourths of Arkansas. Its apparently widespread in North America (Kartesz & Meachum 1999).

 

Eleocharis radicans

This species occurs in California, Arizona, Oklahoma, Texas, and Louisiana, with historic records in Michigan and Virginia (Kartesz & Meachum 1999). With that distribution, I would think it would be at least slightly possible for Arkansas.

 

Eleocharis rostellata Torr.

Edwin B. Smith (1988) listed this taxon as a possible addition to the flora of Arkansas. Kartesz and Meachum's (1999) distribution suggests it is scattered and probably infrequent in the eastern U. S. and perhaps more common in the west.

 

Eleocharis tenuis (Willd.) Shultes var. verrucosa Svenson

The author is still reviewing of the validity of this variety. The species appears to be statewide based on its distribution in Smith (1988). Kartesz and Meachum's (1999) distribution show it in all states surround Arkansas.

 

Eleocharis tortilis (Link.) Schultes

This gulf coastal species occurs in the West Gulf Coastal Plain in southern Arkansas; Smith (1988, pers. commun. 1993) reports it for Ashl and Union counties.

 

Eleocharis tuberculosa (Michx.) R. & S.

Occurs in south central Arkansas from Pula to Unio counties (Smith 1988). I've send records from Calh and Litt counties at LTU.

 

Eleocharis vivparum Link

Recognized as occurring in Arkansas by the Arkansas Flora Committee (unpublished data). Smith (1988) did not mention it in his index.

 

Eleocharis wolfii Gray

Known from Arka, Brad, and Litt counties (Smith 1988); and a specimen from Yell County (USCH).