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• Sorghum bicolor

Sorghum bicolor — sorghum

Facts

Sorghum is an important tropical cereal, native to Africa and widely cultivated in tropical and subtropical Africa and Asia. It was introduced to North America during the slave trade. There are two subspecies in New England. The more frequent (Sorghum bicolor ssp. bicolor) is derived from the cultivated strain, and is found in Connecticut, Massachusetts, Rhode Island and Vermont. The other subspecies (S. bicolor ssp. drummondii) is derived from a hybrid event, and has been collected only in Massachusetts.

Habitat

Anthropogenic (man-made or disturbed habitats), meadows and fields

Characteristics

• Flowers

  Anther length

  2–2.8 mm

  Anther number

  3

  Floret lower bract texture

  the lemma is thin and flexible

  Glume relative length

  one or both glumes are as long or longer than all of the florets

  Glume shape

  the glume is flat or curved in cross-section

  Glume veins

  • 3
  • 5
  • 7 or more

  Inflorescence arrangement

  the plant has two types of spikelets with different reproductive structures

  Inflorescence axis orientation

  • the inflorescence axis is arched or curved outward
  • the inflorescence axis is straight

  Inflorescence branches

  the flowers are attached to branches rather than to the main axis of the inflorescence

  Inflorescence length

  50–600 mm

  Inflorescence type (general)

  the spikelets are borne on stalks or on branches

  Inflorescence type (specific)

  the inflorescence has pairs (or trios) of spikelets, but with one always either missing a stalk or on a shorter stalk than the other

  Lemma awn base

  the awn is attached right at the tip of the lemma

  Lemma awn length

  5–30 mm

  Lemma awn number

  • the lemma has no awn
  • the lemma has one awn on it

  Lemma cross-section

  the lemma is flat or rounded if you cut across the midpoint

  Lemma surface

  the surface of the lemma is relatively smooth (not counting any longitudinal veins or hairs)

  Lemma tip

  the lemma tip is split into two or more points

  Lemma vein number

  • 1
  • 3

  One or more florets

  there is one floret per spikelet

  Spikelet axis tip

  there is no extension of the spikelet axis beyond the tip of the spikelet

  Spikelet disintegration

  the spikelet breaks off below the glumes

  Spikelet length

  3–7 mm

  Spikelet shape

  • the spikelets are elliptic (widest in the middle, tapering to the ends) in profile
  • the spikelets are lanceolate (lance-shaped, widest below the middle and tapering narrowly to the ends) in profile
  • the spikelets are oblong (rectangular, but with rounded ends) in profile

  Spikelets spiny

  the spikelets do not appear spiny

• Growth form

  Horizontal rooting stem

  no

  Lifespan

  the plant lives only a single year or less

  Rhizomes

  no

  Roots

  there are only slender roots on the plant

• Leaves

  Leaf auricles

  the leaves do not have auricles

  Leaf blade width

  5–100 mm

  Leaf ligule length

  1–4 mm

  Leaf ligule type

  the leaf ligule is in the form of a membrane

  Leaf sheath closed around stem

  the margins of the leaf sheath are overlapping and not fused together except in the basal half (or less)

  Leaf sheath hair type

  • there are hairs on the surface of the leaf sheath, but the hairs do not have blisters at their bases
  • there are no hairs on the surface of the leaf sheath

  Leaf sheath hairs

  • there are hairs on the surface of the leaf sheath
  • there are no hairs on the surface of the leaf sheath

• Place

  Habitat

  terrestrial

  New England state

  • Connecticut
  • Massachusetts
  • Rhode Island
  • Vermont

  Specific habitat

  • man-made or disturbed habitats
  • meadows or fields

• Stem, shoot, branch

  Stem orientation

  the stems are upright

  Stem spacing

  the stems grow singly or a few together (they may form diffuse colonies)

Wetland status

Occurs only in non-wetlands. (Wetland indicator code: UPL)

New England distribution and conservation status

From the dichotomous key of Flora Novae Angliae