Sorghum almum

Species category

Weed

Common name

Columbus grass, almum sorghum

Diagnostic characters

Planting unit

SpikeletSpikelet:
One or more florets that are subtended by a pair of bracts called glumes. Spikelets are pedicellate if located on a pedicle and sessile if attached directly to the rachis. Often spikelets with single florets have remnants of a second floret, usually a lemma.

Shape

OvateOvate:
Egg-shaped with basal end the broadest.

Size

  • Length 4–5 mm 
  • Width 1.5–2 mm 
  • Thickness 1.3–1.6 mm 

Color

Yellow to black and mixtures in between

Texture

Some hair on pedicels and rachisRachis:
The central axis of an inflorescence.
segments; spikeletSpikelet:
One or more florets that are subtended by a pair of bracts called glumes. Spikelets are pedicellate if located on a pedicle and sessile if attached directly to the rachis. Often spikelets with single florets have remnants of a second floret, usually a lemma.
smooth.

Lemma

Thin and not visible

Palea

Thin and not visible

Other structures

PedicelPedicel:
The stalk within an inflorescence supporting a single flower or spikelet.
and rachis segmentRachis segment:
A segment of the central axis of the inflorescence (rachis). In some species (e.g. Andropogon) separation of the sessile spikelets occurs when the rachis disarticulates at the spikelet bases leaving the segment of the rachis between spikelets attached to the lower spikelet.
is a mixture of fractured and intact.

Identification notes

Some spikeletsSpikelet:
One or more florets that are subtended by a pair of bracts called glumes. Spikelets are pedicellate if located on a pedicle and sessile if attached directly to the rachis. Often spikelets with single florets have remnants of a second floret, usually a lemma.
disarticulate by fracture and others by abscission. This is a characteristic that is between that of S. halepense and S. × drummondii. The size is also intermediate but natural variation puts individual units into larger and smaller species. The caryopsisCaryopsis:
The single-seeded fruit or grain of the grass family (Poaceae); the fruit wall (pericarp) is united with the seed coat (testa).
is round on top.

Noxious weed seed categories

State Noxious Weed: Alabama, Arizona, California, Colorado, Delaware, Florida, Georgia, Illinois, Indiana, Kansas, Kentucky, Maryland, Michigan, Minnesota, Mississippi, Missouri, New Jersey, Nevada, Ohio, Pennsylvania, South Carolina, Tennessee, Texas, Utah, Virginia, Washington

AOSA examination list

Included

Nomenclature

Family

Poaceae

Valid name

Sorghum almum Parodi

From Left to Right: 1.  Sorghum × almum  2.  Sorghum × drummondii  3.  Sorghum halepense  4.  Sorghum.
From Left to Right: 1. Sorghum × almum 2. Sorghum × drummondii 3. Sorghum halepense 4. Sorghum.
 Sorghum almum.  Spikelets with a round caryopsis on top. Photo by Julia Scher, USDA-APHIS-PPQ.
Sorghum almum. Spikelets with a round caryopsis on top. Photo by Julia Scher, USDA-APHIS-PPQ.
 Sorghum almum.  Spikelets with a pedicel and rachis segment that are a mixture of fractured and intact. Photo by Julia Scher, USDA-APHIS-PPQ.
Sorghum almum. Spikelets with a pedicel and rachis segment that are a mixture of fractured and intact. Photo by Julia Scher, USDA-APHIS-PPQ.
 Sorghum × almum.  Spikelets with a pedicel and rachis segment that are a mixture of fractured and intact. Photo by Julia Scher, USDA-APHIS-PPQ.
Sorghum × almum. Spikelets with a pedicel and rachis segment that are a mixture of fractured and intact. Photo by Julia Scher, USDA-APHIS-PPQ.
 Sorghum almum.  Spikelets with a pedicel and rachis segment with a mixture of fractured and intact segments.
Sorghum almum. Spikelets with a pedicel and rachis segment with a mixture of fractured and intact segments.
 Sorghum almum.  Spikelets with a pedicel and rachis segment with a mixture of fractured and intact segments.
Sorghum almum. Spikelets with a pedicel and rachis segment with a mixture of fractured and intact segments.