Heteropogon

Pers.
Treatment appears in FNA Volume 25. Treatment on page 680.
 TaxonIllustrator 
FNA25 P266 Heteropogon pg 681.jpegHeteropogon contortus
Heteropogon melanocarpus
Hana Pazdírková
Linda A. Vorobik
Hana Pazdírková
Linda A. Vorobik

Plants annual or perennial; cespitose. Culms 20-200 cm, simple or branched. Leaves sometimes aromatic and smelling of lemon oil or citronella; sheaths keeled, sometimes with a row of glandular depressions on the keel; ligules membranous, glabrous or ciliate. Inflorescences terminal and axillary; peduncles usually with 1 rame, sometimes with several in a digitate cluster; rames with 3-10 homogamous, unawned, sessile-pedicellate spikelet pairs on the lower 1/4 - 2/3 and heterogamous, awned, sessile-pedicellate spikelet pairs distally, axes slender, without a translucent median groove; disarticulation in the rames, beneath the sessile spikelets of the heterogamous spikelet pairs, sometimes also below their pedicellate spikelets. Homogamous spikelet units sterile or staminate; calluses poorly developed; glumes membranous, many-veined, keels winged above. Heterogamous spikelet units: sessile spikelets bisexual, terete; calluses 1.5-3 mm, sharp, antrorsely strigose, hairs golden brown; glumes coriaceous, pubescent, concealing the florets; lower glumes enclosing the upper glumes, obscurely 5-9-veined; upper glumes sulcate, 3-veined; lower florets sterile, reduced to a hyaline lemma; upper florets bisexual, lemmas with conspicuous, geniculate awns; awns 5-15 cm, with hairs. Caryopses lanceolate, sulcate on 1 side. Pedicels short, free of the rame axes, not grooved; pedicellate spikelets sterile or staminate, larger than the sessile spikelets; calluses long, glabrous, functioning as pedicels; glumes membranous, many-veined, keels winged above, x = 10, 11.

Distribution

N.Mex., Tex., Calif., Puerto Rico, Virgin Islands, Ala., N.C., S.C., Pacific Islands (Hawaii), Ga., Ariz., Fla.

Discussion

Heteropogon is a pantropical genus of eight to ten species. Two species grow in the Flora region; probably both are introduced. Many grow well on poor soils.

Selected References

None.

Key

1 Glumes of the pedicellate spikelets of the heterogamous spikelet units without glandular pits; plants perennial Heteropogon contortus
1 Glumes of the pedicellate spikelets of the heterogamous spikelet units with a row of glandular pits along the midvein; plants annual Heteropogon melanocarpus

"decumbent" is not a number.

... more about "Heteropogon"
anatomy +  and kranz +
Mary E. Barkworth +
1 (?) +  and 3 (?) +
conspicuous +
geniculate +
5 cm50 mm <br />0.05 m <br /> (15 cm150 mm <br />0.15 m <br />) +
slender +
keeled +  and rounded +
pseudopetiolate +  and branching +
divergent +  and parallel +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
pseudopetiolate +
non-radiate +  and radiate +
well-developed +
usually linear +  and lanceolate occasionally ovate +
reduced +
spikelike +
glabrous +  and strigose +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
lanceolate +
branched +  and simple +
purple +  and reddish +
ascending +  and erect +
20 cm200 mm <br />0.2 m <br /> (200 cm2,000 mm <br />2 m <br />) +
not woody +
N.Mex. +, Tex. +, Calif. +, Puerto Rico +, Virgin Islands +, Ala. +, N.C. +, S.C. +, Pacific Islands (Hawaii) +, Ga. +, Ariz. +  and Fla. +
capillary +
sometimes longer +
concealing +
compressed +  and terete +
shorter or longer +
subtending +
compressed +  and rounded +
unequal +
membranous +  and coriaceous +
golden brown +
uncinate +
bracteate +  and ebracteate +
pedunculate +  and multiple-stalked +
solid +  and hollow +
photosynthetic +
smelling +  and aromatic +
coriaceous +
ciliate +  and glabrous +
membranous +
inconspicuous +
complex +  and simple +
concealed +  and prominent +
pedicellate +
dry +  and fleshy +
elongate +
sessile +, staminate +, pedicellate +  and sessile-pedicellate +
in triplets +  and paired +
1/4 +  and 2/3 +
sterile +, bisexual +, heterogamous +  and homogamous +
heterogamous +, sterile +  and homogamous +
1 +  and 3 +
fused +  and free +
2 +  and 3 +
dome--shaped +  and triangular +
Gramineae +
Heteropogon +
Poaceae tribe Andropogoneae +
membranous +
sessile-pedicellate +
3-veined +  and sulcate +
perennial +  and annual +
plant +  and cespitose +
aquatic +  and terrestrial +
dioecious +, monoecious +  and synoecious +