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Sorghum halepense

Common Name(s):

Phonetic Spelling
SOR-gum ha-le-PEN-see
This plant has low severity poison characteristics.
See below
This plant is an invasive species in North Carolina
Description

Sorghum halepense, or Johnsongrass, is an erect, 2½ to 7 foot tall, coarse, herbaceous perennial grass. This grass has a tendency to spread aggressively and is considered invasive in the southeast and North Carolina.  It can become weedy in disturbed areas of fields and roadsides. Sorghum halepense is adapted to a wide variety of habitats including open forests, old fields, ditches and wetlands. It spreads aggressively and can form dense colonies that displace native vegetation and restrict tree seedling establishment. This plant is listed as a noxious weed in 19 states. Sometimes this grass invades gardens and both the seeds and rhizomes can be transported and introduced into new areas in contaminated bags of topsoil.

The plant prefers full sun, moist to mesic conditions, and fertile loamy soil. However, this robust grass is easy to grow in a wide range of soil types, tolerates drier locations and soil containing gravel or clay. Most growth occurs during the summer and episodes of hot dry weather are tolerated. This species is not very winter hardy, tolerating occasional temperatures down to about 23°F so long as the soil is not too wet. It is best adapted to warm humid summer-rainfall areas in the subtropics, not growing well in strictly tropical areas. Classified as a short day plant, it does not flower if the daylight hours exceed about 13 hours per day. The root system is fibrous and long-rhizomatous and often forms clonal colonies from the rhizomes. This grass was introduced from the eastern Mediterranean area or the Middle East as a pasture grass in southeastern United States, and it has since spread across a large area of the United States.

In the United States, Johnsongrass was introduced in South Carolina from Turkey around 1830. William Johnson, whom the plant is named after, established Johnsongrass along the Alabama River in the 1840s as a forage species, and Johnsongrass spread rapidly across the South. Johnsongrass is now widely escaped from cultivation in much of the United States. It is most invasive in the Southeast, although it is widespread in central California and New Mexico. Sorghum species are interfertile, and Johnsongrass readily hybridizes with sorghum (S. bicolor). In the southern Great Plains and South, plants classified as Johnsongrass may actually be stable Johnsongrass × sorghum introgrades .

Insects, Diseases, and Other Plant Problems:

No known insect or disease problems. The pollen is known to induce hay fever. In riparian and other areas where Johnsongrass is highly productive, Johnsongrass may promote fire spread by increasing fine fuel loads above historical levels. Studies are needed on the fire ecology of Johnsongrass in North American.

 

See this plant in the following landscape:
Cultivars / Varieties:
Tags:
#invasive#poisonous#weed#weedy#grass#herbaceous perennial#tall grass#weedy grass#perennial weed
 
Cultivars / Varieties:
Tags:
#invasive#poisonous#weed#weedy#grass#herbaceous perennial#tall grass#weedy grass#perennial weed
  • Attributes:
    Genus:
    Sorghum
    Species:
    halepense
    Family:
    Poaceae
    Life Cycle:
    Perennial
    Recommended Propagation Strategy:
    Division
    Seed
    Country Or Region Of Origin:
    Eastern Mediteranean and Middle East
    Distribution:
    throughout
    Fire Risk Rating:
    high flammability
    Wildlife Value:
    pasture grass
    Play Value:
    Easy to Grow
    Wildlife Cover/Habitat
    Wildlife Food Source
    Wildlife Larval Host
    Wildlife Nesting
    Particularly Resistant To (Insects/Diseases/Other Problems):
    drought
    Edibility:
    Low toxicity if eaten. Seed cam be eaten in small quantities raw or cooked. Used whole in a similar manner to rice or millet, or ground into a flour for bread, cakes.
  • Whole Plant Traits:
    Plant Type:
    Herbaceous Perennial
    Poisonous
    Weed
    Habit/Form:
    Arching
    Dense
    Erect
    Spreading
    Growth Rate:
    Rapid
    Maintenance:
    High
    Texture:
    Coarse
  • Cultural Conditions:
    Light:
    Full sun (6 or more hours of direct sunlight a day)
    Soil Texture:
    Clay
    High Organic Matter
    Loam (Silt)
    Shallow Rocky
    Soil pH:
    Acid (<6.0)
    Alkaline (>8.0)
    Neutral (6.0-8.0)
    Soil Drainage:
    Moist
    Occasionally Dry
    Available Space To Plant:
    Less than 12 inches
    NC Region:
    Coastal
    Mountains
    Piedmont
    USDA Plant Hardiness Zone:
    7b, 7a, 8b, 8a, 9b, 9a, 10b, 10a
  • Fruit:
    Display/Harvest Time:
    Fall
    Fruit Type:
    Capsule
    Fruit Length:
    < 1 inch
    Fruit Width:
    < 1 inch
    Fruit Description:
    Seeds ripen September and October. Capsules are 1 inch with husk and 1/2 inch without.
  • Flowers:
    Flower Color:
    Brown/Copper
    Flower Inflorescence:
    Panicle
    Raceme
    Flower Bloom Time:
    Fall
    Summer
    Flower Size:
    > 6 inches
    Flower Description:
    Each panicle is up to 18 inches long and 9 inches wide, broader toward the bottom than the top and somewhat airy in appearance when fully open. Johnson Grass has a spreading panicle of florets with slender branches and branchlets. Inflorescence a panicle with branches tipped by a raceme. Panicle open; lanceolate, or pyramidal. Primary panicle branches whorled at most nodes; moderately divided. Johnson Grass has a spreading panicle of florets with slender branches and branchlets. Inflorescence a panicle with branches tipped by a raceme. Panicle open; lanceolate, or pyramidal. Primary panicle branches whorled at most nodes; moderately divided.
  • Leaves:
    Leaf Color:
    Green
    White
    Leaf Feel:
    Smooth
    Leaf Type:
    Sheath
    Leaf Arrangement:
    Alternate
    Leaf Shape:
    Lanceolate
    Leaf Margin:
    Entire
    Hairs Present:
    Yes
    Leaf Length:
    > 6 inches
    Leaf Width:
    1-3 inches
    Leaf Description:
    Leaves occur primarily along the lower half of each stem. The leaf blades are up to 24 inches long and 1 to 3 inches across; they are widely spreading, arching, or ascending. The upper blade surface is medium to dark green, while the lower blade surface is more pale; both are smooth. The larger leaf have prominent central veins that are pale-colored. The junctions of leaf blades and sheaths have narrow strips of fine white hairs. Leaves occur primarily along the lower half of each stem.
  • Stem:
    Stem Color:
    Green
    Stem Is Aromatic:
    No
    Stem Cross Section:
    Round
    Stem Form:
    Straight
    Stem Surface:
    Smooth (glabrous)
    Stem Description:
    The stems are light green, terete, and glabrous. Each culm terminates in a panicle of spikelets.
  • Landscape:
    Landscape Location:
    Lawn
    Meadow
    Naturalized Area
    Design Feature:
    Mass Planting
    Resistance To Challenges:
    Drought
    Dry Soil
    Problems:
    Invasive Species
    Weedy
  • Poisonous to Humans:
    Poison Severity:
    Low
    Poison Symptoms:
    Causes low toxicity in humans if the leaves are eaten, which can occur if the plant is mixed with, or mistaken for, grain sorghum. There have been no known cases of human poisoning. The foliage that becomes wilted from frost or hot, dry weather can contain sufficient amounts of hydrogen cyanide to harm cattle and horses if it is eaten in quantity.
    Poison Toxic Principle:
    Cyanogenic glycoside
    Causes Contact Dermatitis:
    No
    Poison Part:
    Leaves