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grain sorghum, great millet, Milo, shattercane, sorghum


Habit Plants annual or short-lived perennials; often tillering, without rhizomes. Plants annual or perennial.

50-500+ cm tall, 1-5 cm thick, sometimes branching above the base;

nodes glabrous or appressed pubescent;

internodes glabrous.

50-500+ cm;

internodes solid.


not aromatic, basal and cauline;

auricles absent;

ligules membranous and ciliate or of hairs;

blades usually flat.


5-60 cm long, 3-30 cm wide, open or contracted, primary branches compound, terminating in rames with 2-7 spikelet pairs;

disarticulation usually not occurring or tardy.


terminal, panicles with evident rachises;

primary branches whorled, compound, the ultimate units rames;

rames with most spikelets in heterogamous sessile-pedicellate spikelet pairs, terminal spikelet unit on each rame usually a triplet of 1 sessile and 2 pedicellate spikelets, rame axes without a translucent median line;

disarticulation in the rames below the sessile spikelets, sometimes also below the pedicellate spikelets (cultivated taxa not or only tardily disarticulating).


often exposed at maturity.


1-2.6 mm.

slender, neither appressed nor fused to the rame axes.


1-4 mm;

blades 5-100 cm long, 5-100 mm wide, sometimes glabrous.


spikelets bisexual, 3-9 mm, lanceolate to ovate;

calluses blunt;

glumes coriaceous to membranous, glabrous, densely hirsute, or pubescent, keels usually winged;

upper lemmas unawned or with a geniculate, twisted, 5-30 mm awn;

anthers 2-2.8 mm.

spikelets dorsally compressed, calluses blunt or pointed;

lower glumes dorsally compressed and rounded basally, 2-keeled or winged distally, 5-15-veined, usually unawned;

upper glumes 2-keeled, sometimes awned;

lower florets reduced to hyaline lemmas;

upper florets pistillate or bisexual, lemmas hyaline, sometimes awned.


spikelets 3-6 mm, usually shorter than the sessile spikelets, staminate or sterile.

spikelets staminate or sterile, well-developed, often subequal to the sessile spikelets in size, x = 10.


= 20, 40.

Sorghum bicolor


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from FNA
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Sorghum bicolor was domesticated in Africa 3000 years ago, reached northwestern India before 2500 B.C., and became an important crop in China after the Mongolian conquest. It was introduced to the Western Hemisphere in the early sixteenth century, and is now an important crop in the United States and Mexico. Numerous cultivated strains exist, some of which have been formally named. They are all interfertile with each other and with other wild species of Sorghum.

The treatment presented here is based on de Wet (1978) and is somewhat artificial. Sorghum bicolor subsp. arundinaceum is the wild progenitor of the cultivated strains, all of which are treated as S. bicolor subsp. bicolor. These strains tend to lose their distinguishing characteristics if left to themselves. They will also hybridize with subsp. arundinaceum, and these hybrids can backcross to either parent, resulting in plants that may strongly resemble one parent while having some characteristics of the other. All such hybrids and backcrosses are treated here as S. bicolor subsp. xdrummondii.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Most of the approximately 25 species of Sorghum are native to tropical and subtropical regions of the Eastern Hemisphere, but one is native to Mexico. Two have been introduced into the Flora region. Some species are grown as forage, although they produce cyanogenic compounds. Sorghum bicolor is widely cultivated, being used as a grain, for syrup, and as a flavoring for beer.

Spangler (2000) found, using ndhF data, that Sorghum is polyphyletic, forming two distinct clades. The two species treated here were in the same clade. He found Microstegium and Miscanthus to be more closely related to Sorghum than Sorghastrum.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

1. Inflorescences branches remaining intact at maturity; caryopses exposed at maturity; sessile spikelets 3-9 mm long, elliptic to oblong
subsp. bicolor
1. Inflorescences branches rames, disarticulating at maturity, sometimes tardily; caryopses not exposed at maturity; sessile spikelets 5-8 mm long, lanceolate to elliptic.
→ 2
2. Rames readily disarticulating
subsp. arundinaceum
2. Rames disarticulating tardily
subsp. ×drummondii
1. Plants perennial, rhizomatous; spikelets disarticulating at maturity; caryopses not exposed at maturity
S. halepense
1. Plants usually annual, sometimes short-lived perennials; spikelets either not disarticulating or doing so tardily; caryopses often exposed at maturity
S. bicolor
Source FNA vol. 25, p. 628. FNA vol. 25, p. 626. Author: Mary E. Barkworth;.
Parent taxa Poaceae > subfam. Panicoideae > tribe Andropogoneae > Sorghum Poaceae > subfam. Panicoideae > tribe Andropogoneae
Sibling taxa
S. halepense
Subordinate taxa
S. bicolor subsp. arundinaceum, S. bicolor subsp. bicolor, S. bicolor subsp. ×drummondii
S. bicolor, S. halepense
Synonyms S. vulgare
Name authority (L.) Moench Moench
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