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Publication #HS962

Identification of Sedge and Sedge-Like Weeds in Florida Citrus1

Stephen H. Futch and David W. Hall2

Sedges are annual or mostly perennial grass-like plants with aerial flower-bearing stems. In annual forms, the stem is solitary to mostly several with basal leaves. Perennial forms have a thick rootstock or an erect to horizontal underground rhizome usually with shortened internodes.

Sedges usually have triangular stems with leaves arranged in groups of three and are similar to grasses in many attributes. Sedge species may be found in a wide range of conditions, ranging from very wet to dry and in many soil types.

In sedges, as well as grasses, the seed head will be produced at the end of an aerial, erect stem. This three-sided stem is usually solitary and will be tufted with basal leaves. Root systems are fibrous, including species such as yellow and purple nutsedge which produce rhizomes and tubers. Flowers are extremely small and numerous and arranged in spikelets atop the stem.

Sedges are of little economic value to man but can be very competitive with the desired crop for water, nutrients and space.

Sedges

Yellow Nut Sedge – Cyperus esculentus (Fig. 1)

Figure 1. 

Yellow Nut Sedge


[Click thumbnail to enlarge.]

Season:

rapidly spreading, aggressive, erect perennial

Stem:

slender, smooth, pithy and 3-angled (triangular in cross section), arising from rhizomes, tubers or basal bulbs

Height:

up to 24 inches tall

Roots:

fibrous, branched, with tubers on rhizomes

Leaf blade:

yellowish green, prominent midvein, flat or slightly corrugated, 0.2 to 0.5 inch wide, waxy or shiny appearance, 3-ranked and growing from basal bulb, leaves usually as long or longer than flowering stem, blade tapering to long thin tip

Seed head:

short, subtending leaf-like bracts, flattened, yellowish-brown spikelets, clustered around the ends of a few to 10 branches of unequal length

Propagated by:

seeds, creeping rootstock (rhizomes), or small underground nutlets. Nutlets (tubers) are brown, round, lack hairs, 0.5 to 0.75 inch long and may lie dormant in soil several years. Nutlets are individually produced and sweet or neutral to taste.

Comments:

prefers moist to dry cultivated soils and does not tolerate shade

Purple Nut Sedge – Cyperus rotundus (Fig. 2)

Figure 2. 

Purple Nut Sedge


[Click thumbnail to enlarge.]

Season:

rapidly spreading, aggressive, erect perennial

Stem:

erect, smooth, solid, triangular in cross section, arising from tuber or basal bulb, and usually longer than leaves

Height:

up to 1.5 feet high

Roots:

extensively branched, fibrous, with tubers on rhizomes

Leaf blade:

deep-green, originates from the base of the plant, 3-ranked and grass-like, flat or slightly corrugated, prominent mid vein, 1/8 to 1/3 inch wide, and abruptly tapering to sharp point. Leaf is dark green, smooth, shiny, and usually shorter than stem.

Seed head:

short subtending leaf-like bracts, numerous, flattened, red to purple brown spikelets clustered at the end of the stalk on a few to several branches

Propagated by:

slender creeping rootstocks (rhizomes) and nutlets (tubers). Nutlets are covered with hairs and are bitter to the taste. Multiple nutlets are produced forming a tuber chain.

Comments:

thrives in moist sandy soils but does not tolerate shade, often thought to be the world's worst weed

Green Kyllinga – Kyllinga brevifolia (Cyperus brevifolius) (Fig. 3)

Figure 3. 

Green Kyllinga


[Click thumbnail to enlarge.]

Season:

mat-forming perennial

Stem:

dark green, arising from purple rhizomes, with 3 subtending leaves on the end of the flower stalk

Height:

up to 18 inches tall, frequently about 6 inches tall

Roots:

fibrous

Leaf blade:

dark green, 1 to 5 inches long and narrow

Flower stalk:

triangular in cross section

Seed head:

subtended by a few leaf-like bracts, usually one, occasionally 2 or 3 heads, initially pale green and often turning brown at maturity, globe-shaped and 1/4 inch in diameter

Seed:

oval, flat in cross section (1/16 inch long)

Propagated by:

seeds and rhizomes

Comments:

found in low areas where moisture is excessive, can form large mats

Annual Sedge, Watergrass – Cyperus compressus (Fig. 4)

Figure 4. 

Annual Sedge, Watergrass


[Click thumbnail to enlarge.]

Season:

annual

Stem:

green, smooth

Height:

4 to 18 inches tall

Roots:

reddish, fibrous, extensively branching, lacks rhizomes

Leaf blade:

basal, 3-ranked, elongated and narrow (0.1 inch wide) and usually equal to or shorter than stem

Seed head:

few to several, flat, greenish, spikelets at end of stem

Seed:

dull brown, 3-sided, 1/16 inch long at maturity

Propagated by:

seeds

Comments:

found in sandy, moist soils, can form large tangled masses

Cylindric Sedge – Cyperus retrorsus (Fig. 5)

Figure 5. 

Cylindric Sedge


[Click thumbnail to enlarge.]

Season:

erect perennial

Stem:

densely tufted

Height:

up to 20 inches tall

Roots:

fibrous, may form short rhizomes

Leaf blade:

bright green, flat, smooth

Seed head:

with 3-7 leaf-like bracts at top of stem, few to several branches of tight cylindrical clustered spikelets, green and turning brown to black at maturity

Propagated by:

seeds and the very short rhizomes

Comments:

grass-like, occurs in most sandy habitats, extremely common

Globe Sedge – Cyperus croceus (Cyperus globulosus) (Fig. 6)

Figure 6. 

Globe Sedge


[Click thumbnail to enlarge.]

Almost identical to Cylindric Sedge. Differs in that the seed heads are globular instead of cylindrical.

Season:

perennial

Stem:

densely tufted

Height:

up to 20 inches tall

Roots:

fibrous, may form short rhizomes

Leaf blade:

bright green, flat, smooth

Seed head:

with 3-7 leaf-like bracts at top of stem, few to several branches of tight globular clustered spikelets, green and turning brown to black at maturity

Propagated by:

seeds and very short rhizomes

Comments:

grass-like, occurs in dry to moist sandy habitats, extremely common

Surinam Sedge – Cyperus surinamensis (Fig. 7)

Figure 7. 

Surinam Sedge


[Click thumbnail to enlarge.]

Season:

perennial

Stem:

erect, triangular with rounded edges, covered with downward curving prickles

Height:

up to 3 feet tall

Roots:

fibrous

Leaf blade:

up to 1/2 inch wide, green, flat

Seed head:

numerous, flattened, heads of spikelets, subtended by a few to several leaf-like bracts

Seed:

triangular, 1/32 inch long, tiny bump at bottom end

Propagated by:

seeds

Comments:

found in ditches and moist, wet sites, easily identified by lightly pulling fingers upward on the stem to check for the downward curving prickles

Texas Sedge – Cyperus polystachyos (Fig. 8)

Figure 8. 

Texas Sedge


[Click thumbnail to enlarge.]

Season:

annual

Stem:

erect, rounded, smooth

Height:

up to 20 inches tall

Roots:

fibrous

Leaf blade:

up to 1/8 inch wide, basal

Seed head:

few to many branches, many flattened spikelets, clustered at ends of branches

Seed:

weakly triangular, 1/32 inch long, covered with tiny bumps, brownish-gray

Propagated by:

seeds

Comments:

extremely common, a facultative species growing in all dry and wet soils

Sedge-Like Weeds

Doveweed – Murdannia nudiflora (Fig. 9)

Figure 9. 

Doveweed


[Click thumbnail to enlarge.]

Season:

warm season annual

Stem:

fleshy, creeping

Height:

up to 12 inches tall

Roots:

fibrous, rooting at nodes

Leaf blade:

fleshy, alternate, narrow, lanced-shaped

Leaf sheath:

soft hairs on upper margin

Flower:

blue to purple, 1/4-1/2 inch wide, in open clusters

Propagated by:

seeds

Comments:

usually found in moist areas, can be very prolific, often spread by birds

Common Spiderwort, Spiderwort – Tradescantia ohiensis (Fig. 10)

Figure 10. 

Common Spiderwort, Spiderwort


Credit: Photo provided by David Drew.
[Click thumbnail to enlarge.]

Season:

perennial

Stem:

smooth

Height:

up to 30 inches tall

Roots:

fibrous

Leaf blade:

smooth, linear or lanceolate, folded lengthwise, fleshy

Leaf sheath:

smooth

Flower:

3/4-1 inch wide, blue, 3 petals, in umbel-like clusters, clusters subtended by 1-3 leaf-like bracts, flowers throughout the year

Propagated by:

seeds

Comments:

prefers moist areas, often forms large clumps with numerous stems

Tropical Spiderwort, Tropical Dayflower – Commelina benghalensis (Fig. 11)

Figure 11. 

Tropical Spiderwort, Tropical Dayflower


[Click thumbnail to enlarge.]

Season:

perennial

Stem:

fleshy, rooting at nodes, some branching underground

Height:

up to 10 inches tall

Roots:

fibrous

Leaf blade:

somewhat fleshy, oval, margins wavy

Leaf sheath:
clasping stem
Flower:

1/8 inch wide, two bright blue and one pale blue petals, subtended by a boat-shaped bract that has the basal margins united; underground branches have flowers that do not open and produce fruit

Propagated by:

seeds from both above and underground flowers

Comments:

a rapidly expanding weed, not well known, quite common in open sandy areas

Footnotes

1.

This document is HS962, one of a series of the Horticultural Sciences Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Published March 2004. Reviewed June 2012. This research was supported by the Florida Agricultural Experiment Station, and approved for publication as Journal Series No. T-00645. Visit the EDIS website at http://edis.ifas.ufl.edu.

2.

Stephen H. Futch, Extension Agent IV, Citrus REC, Lake Alfred, Florida, Horticultural Sciences Department, Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611; and David W. Hall, D. W. Hall Consultant, Inc., Gainesville, FL, formerly with University of Florida, Institute of Food and Agricultural Sciences and Florida Museum of Natural History.


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U.S. Department of Agriculture, UF/IFAS Extension Service, University of Florida, IFAS, Florida A & M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Nick T. Place, dean for UF/IFAS Extension.