Whole Document Navigator (Click Here)    ---------------------------------- Top of Document Guineagrass -- Panicum maximum (Fig. 1) Narrowleaf Guineagrass -- Panicum maximum (Fig. 2) Torpedograss -- Panicum repens (Fig. 3) Broadleaf Signalgrass -- Urochloa platyphylla (Brachiaria platyphylla) (Fig. 4) Smallflowered Alexandergrass -- Urochloa subquadripara (Brachiaria subquadripara) (Fig. 5) Southern Sandbur -- Cenchrus echinatus (Fig. 6) Crowfootgrass -- Dactyloctenium aegyptium (Fig. 7) Natalgrass -- Melinis repens (Rhynchelytrum repens) (Fig. 8) Bermudagrass -- Cynodon dactylon (Fig. 9) Johnsongrass -- Sorghum halepense (Fig. 10) Vaseygrass -- Paspalum urvillei (Fig. 11) Goosegrass -- Eleusine indica (Fig. 12) Vegetative Grass Parts Footnotes Disclaimer Copyright Infomation

Identification of Grass Weeds in Florida Citrus¹

Stephen H. Futch and David W. Hall²

Grass weeds commonly found in citrus can be identified by looking for specific characteristics of the plant. These specific characteristics can include, but are not limited to, the width of the leaf blade, presence or absence of hairs, growth habit, type of seed head, root system, and plant size. The entire leaf can be further divided into the sheath, ligule, and blade to also aid in identification. The sheath is the lower part of the leaf that fits around the stem. The projection at the base of the leaf blade is called a ligule. The ligule may be either a membrane or a fringe of hairs or a combination of both. Additionally, the presence of other factors such as stolons (above ground stems) or rhizomes (under ground stems) can also be helpful in plant identification.

Grass seedlings have one leaf as they emerge from seed, whereas broadleaf plants have two. Leaves are generally narrow, grow upright, and have parallel veins in the leaf blade. Grasses usually grow and develop with a fibrous root system that lacks a central taproot. The stems are round and can be either hollow or solid.

Grasses are classified as either annuals or perennials. Annual plants will complete their life cycle in one year (12 months) or less. Perennials will live more than two years (24 months).

The following 12 grass plants are weeds commonly found in citrus groves and other disturbed and cultivated sites in the state of Florida. The characteristics discussed in this article should help you with identification. Please see Figure 13 for a line drawing of the parts of the leaf.

Guineagrass -- Panicum maximum (Fig. 1)

Figure 1. Guineagrass

Season: annual or perennial

Stem:

height: to 16 feet
growth habit: densely tufted, sometimes bending, rooting at nodes
roots: fibrous
hairs: none to hairy
joints: smooth to usually hairy

Leaf:
sheath: usually hairy or smooth
ligule: small membrane, fringed with tiny hairs
blade: light green, flat, up to 1 3/4 inches in width and up to 30 inches long

Seed head: large, to 3 feet long with spreading branches, lowest branches always whorled

Seed: small, with fine wrinkles, 1/8 inch (2.7-3.7 mm) long

Propagation: reproduces by seeds and rarely by stolons

Comments: identified by the lowest seed head branches whorled and seeds with wrinkles

Narrowleaf Guineagrass -- Panicum maximum (Fig. 2)

Figure 2. Narrowleaf Guineagrass

Characteristics are similar to guineagrass except for the following:

Season: perennial

Stem:

height: to 5 feet, but can lean and climb through other vegetation reaching 20 feet or more
growth habit: bending, rooting, and branching at nodes
Leaf:
blade: to 1/2 inch in width

Propagated by: seeds and stolons

Comments: prolifically branching at nodes, can literally fill a citrus tree with branches and grow through and out of the top of the tree; identified by the same characteristics as guineagrass, but blade only 1/2 inch or less wide

Torpedograss -- Panicum repens (Fig. 3)

Figure 3. Torpedograss

Season: perennial

Stem:

height: 1-3 feet tall
growth habit: erect or leaning stems, grows horizontally by underground rhizomes which sprout stems from nodes, end of underground rhizome is white and sharply torpedo-shaped
roots: fibrous with rhizomes
hairs: none
joints: smooth

Leaf:

sheath: with or without hairs, sheath margin fringed with short hairs and with long hairs at top
ligule: tiny membrane fringed with tiny hairs
blade: narrow, 2-10 inches long, 1/16 to 1/4 inch wide, folded or flat, long soft hairs on upper surface

Seed head: stiff, branched and open, 3-9 inches long

Seed: 1/8 inch (2.2-3.1 mm) long, white, smooth

Propagated by: primarily by rhizomes, but seeds germinate easily

Comments: requires moisture to germinate, prefers wet areas; identified by white rhizomes, white seeds on stalks, and soft hairs on upper blade surface

Broadleaf Signalgrass -- Urochloa platyphylla (Brachiaria platyphylla) (Fig. 4)

Figure 4. Broadleaf signalgrass

Season: summer annual

Stem:

height: to 3 feet tall
growth habit: spreading, multi-branched, rooting at lower nodes
roots: fibrous
hairs: none
joints: hairy

Leaf:
sheath: hairs on margin and sometimes on sheath
ligule: tiny membrane with very short hairs
blade: to 6 inches long and to 1/2 inch wide

Seed head: up to 12 inches long with 2-6, 1-3 inch long branches

Seed: 3/16 inch (3.5-4.7 mm) long, smooth

Propagated by: seeds

Comments: identified by fibrous roots, hairy ligule, broad blades, smooth sheath, alternate branches in seed head, smooth seeds

Smallflowered Alexandergrass -- Urochloa subquadripara (Brachiaria subquadripara) (Fig. 5)

Figure 5. Smallflowered Alexandergrass

Season: short-lived perennial

Stem:

height: to 2 feet tall
growth habit: erect to bending, rooting at nodes, with weak stolons
roots: fibrous
hairs: none
joints: smooth
Leaf:
sheath: stiff hairs, sheath margin usually fringed with hairs
ligule: tiny membrane with a fringe of hairs
blade: with scattered stiff hairs

Seed head: 2 to 7 alternate branches

Seed: 1/8 inch (3.3-3.8 mm) long, smooth

Propagated by: seeds and stolons

Comments: blade tips turn white after frost or cutting; identified by fibrous roots, rooting stems, hairy ligule, hairy sheath, hairy blade, alternate branches in seed head, smooth seeds, leaf tips often white

Southern Sandbur -- Cenchrus echinatus (Fig. 6)

Figure 6. Southern Sandbur

Season: summer annual

Stem:

height: ½ to 2 feet tall
growth habit: erect or spreading, in clumps, rooting at lower nodes
roots: fibrous
hairs: none
joints: smooth

Leaf:

sheath: smooth, margin often hairy
ligule: hairy ring
blade: to 12 inches long and to 1/2 inch wide, sometimes hairy on upper surface

Seed head: contains a spike of spiny burs which contain 2 to 3 seeds per bur, 5-22 burs per spikelet

Seed: 1/4 inch (4.8-6.8 mm) long, smooth

Propagated by: seed

Comments: identified by spiny burs with flattened spines over most of the bur and a ring of round spines arranged in a crown around the base

Crowfootgrass -- Dactyloctenium aegyptium (Fig. 7)

Figure 7. Crowfootgrass

Season: summer annual

Stem:

height: to 2 feet tall
growth habit: upward bending, spreading and branching, forming a mat which may root at nodes
roots: fibrous
hairs: none
joints: smooth

Leaf:

sheath: lacking hairs
ligule: membranous with a fringe of hairs
blade: with or without hairs, blade margin with long ciliate hairs from base to almost tip

Seed head: 1-7 short, finger-like thick spikes joined at the same point at tip of stem, branches with claw-like tips

Seed: 1/8 inch (4.0 mm) long, 3-5 joined together

Propagated by: seeds

Comments: identified by fibrous roots, stiff hairs on blade margins, tip of seed head branches claw-like

Natalgrass -- Melinis repens (Rhynchelytrum repens) (Fig. 8)

Figure 8. Natalgrass

Season: short lived perennial

Stem:

height: to 40 inches
growth habit: erect or ascending, from clumps
roots: fibrous
hairs: none
joints: smooth

Leaf:

sheath: smooth or hairy
ligule: tiny membrane, fringed with hairs
blade: flat, to 7 inches long, to 1/4 inch wide, smooth to sandpapery to hairy

Seed head: white at first but turns a showy red or purple, often fading to white again after maturity

Seed: 3/16 inch (2.5-4.7 mm) long, hairy

Propagated by: seeds

Comments: identified by a clump with fibrous roots, hairy seed heads, with long reddish hairs on seeds

Bermudagrass -- Cynodon dactylon (Fig. 9)

Figure 9. Bermudagrass

Season: creeping perennial

Stem:

height: 4 to 36 inches tall
growth habit: spreading
roots: fibrous, rooting from nodes, stolons, and rhizomes
hairs: none
joints: flattened, hairless, bearing dead leaf sheaths at each joint
Leaf:
sheath: with or without hairs, sheath margin with long hairs at collar
ligule: membrane with a fringe of hairs
blade: with or without hairs on both surfaces, 1-7 inches long and 1/10-2/10 inch wide

Seed head: erect, with 3 to 9 finger-like branches 1-4 inches (3-10 cm) long, all at tip

Seed: flattened, 1/8 inch (2.0-3.2 mm) long, hairy

Propagated by: seed, surface-creeping stems (stolons), and rhizomes

Comments: used extensively for forage and turf; identified by rhizomes, stolons, narrow blades, erect hairs resembling cat's whiskers on margins of collar

Johnsongrass -- Sorghum halepense (Fig. 10)

Figure 10. Johnsongrass

Season: perennial

Stem:

height: 4-10 feet tall
growth habit: coarse, very leafy, erect, perennial, forming dense stands
roots: fibrous with thick rhizomes
hairs: none
joints: smooth

Leaf:

sheath: with a few hairs
ligule: prominent membranous ligule
blade: with prominent white midvein, hairs at the base of leaf blade, to 20 inches long and 1/4 to 1 inch wide

Seed head: large, open, often reddish to purple in color, 6-24 inches (15-60 cm) long

Seed: hairy, about 1/8-1/4 inch (3.8-6.3 mm) long

Propagation: reproduces by seeds and rhizomes, the rhizomes are scaly and sharp-pointed

Comments: identified by thick white rhizomes, a membranous ligule, large seed head, hairy seeds

Vaseygrass -- Paspalum urvillei (Fig. 11)

Figure 11. Vaseygrass

Season: perennial

Stem:

height: 2 to 9 feet tall
growth habit: erect, forming large clumps
roots: fibrous with very short rhizomes
hairs: none
joints: smooth

Leaf:

sheath: hairy to smooth
ligule: membranous to 3/4 inch (21.0 mm) long, pointed
blade: with tuft or fringe of long hairs at base just above ligule otherwise without other hairs

Seed head: erect, 4 to 30 spreading branches, spikelet paired

Seed: 3/16 inch (2.0-2.7 mm) long, hairy, flat on one side

Propagated by: seeds

Comments: identified by growing in clumps, membranous ligules, hairy seeds, a band of hairs at base of blade next to ligule, stiff hairs on sheaths at bottom of stem, sheaths smooth at top of stem

Goosegrass -- Eleusine indica (Fig. 12)

Figure 12. Goosegrass

Season: summer annual, or short lived perennial

Stem:

height: to 2 feet tall, stems somewhat flattened at base, forming a basal clump with radiating stems, usually nearly prostrate (low growing)
growth habit: erect to spreading with branched stems which occasionally root from nodes
roots: fibrous
hairs: none
joints: smooth

Leaf:

sheath - with hairs on margin and long hairs at margin of collar
ligule - membranous with a fringe of hairs
blade - to 15 inches long and 3/8 inch wide; upper surface smooth, or with scattered hairs

Seed head: 2 to 7 finger-like branches located at stem end, 1-6 inches long, all clustered at stem tip, usually with one branch on stem below tip

Seed: 1/8 inch (2.7-4.2 mm) long, smooth

Propagated by: seeds

Comments: especially common in compacted soils; prolific seed producer; identified by fibrous roots, usually flattened stems, clear/white sheath margins, seed head with 1 branch below tip

Vegetative Grass Parts

Figure 13. Vegetative grass parts. From: David W. Hall. 1982. Weeds in the Sunshine: Information for control of Florida weeds - Common weedy grass identification using vegetative characteristics. Univ. Fla., IFAS, Fla. Coop. Ext. Serv. A-82-8.

---

Footnotes

1. This document is HS955, one of a series of the Horticultural Sciences Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Published February 2004. This research was supported by the Florida Agricultural Experiment Station, and approved for publication as Journal Series No. T-00610. Visit the EDIS Web site at http://edis.ifas.ufl.edu.

2. Stephen H. Futch, Extension Agent IV, Citrus REC, Lake Alfred, FL, Horticultural Sciences Department, Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, 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.

---

The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other extension publications, contact your county Cooperative Extension service.

U.S. Department of Agriculture, Cooperative Extension Service, University of Florida, IFAS, Florida A. & M. University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Larry Arrington, Dean.

---

Copyright Information

This document is copyrighted by the University of Florida, Institute of Food and Agricultural Sciences (UF/IFAS) for the people of the State of Florida. UF/IFAS retains all rights under all conventions, but permits free reproduction by all agents and offices of the Cooperative Extension Service and the people of the State of Florida. Permission is granted to others to use these materials in part or in full for educational purposes, provided that full credit is given to the UF/IFAS, citing the publication, its source, and date of publication.