Dichanthium sericeum

(R. Br.) A. Camus
Common names: Queensland bluegrass
Introduced
Treatment appears in FNA Volume 25. Treatment on page 637.

Plants annual or perennial; tufted or cespitose. Culms 50-120 cm; nodes densely pilose, hairs about 2 mm. Sheaths with scattered papillose-based hairs; ligules 1-2 mm; blades 5-25 cm long, 2-5 mm wide. Rames 1-7, 3-7 cm, subdigitate, often glaucous and white-villous, spikelet-bearing to the base, basal spikelet pairs consisting only of glumes; internodes pubescent, hairs immediately below the nodes to 1.5 mm. Sessile bisexual spikelets 2.5-4.5 mm long, 1-1.4 mm wide; lower glumes 5-10-veined, with 0.7-1.5 mm hairs on the basal 1/2 and about 3 mm papillose-based hairs on the distal portion of the keels and in a transverse subapical arch; awns 2-3.5 cm, twice-geniculate. Pedicellate spikelets about 3 mm, usually sterile. 2n = 20.

Distribution

Pacific Islands (Hawaii), Fla., Tex., Miss.

Discussion

Dichanthium sericeum is an Australian species. There are two subspecies: D. sericeum (R. Br.) A. Camus subsp. sericeum is a perennial with sessile spikelets 4-4.5 mm long and to 1-1.4 mm wide, 9-10-veined lower glumes, and rames more than 4 cm long; D. sericeum subsp. humilius (J.M. Black) B.K. Simon is an annual, with sessile spikelets up to 4 mm long and about 1 mm wide, 5-7-veined lower glumes, and rames less than 4 cm long. Dichanthium sericeum subsp. sericeum is established in Texas and Florida.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

... more about "Dichanthium sericeum"
anatomy +  and kranz +
Mary E. Barkworth +
(R. Br.) A. Camus +
1 (?) +  and 3 (?) +
2 times-geniculate +
2 cm20 mm <br />0.02 m <br /> (3.5 cm35 mm <br />0.035 m <br />) +
keeled +  and rounded +
staminate +  and homomorphic +
sterile +  and homogamous +
pseudopetiolate +  and branching +
divergent +  and parallel +
intravaginal +, extravaginal +, branching +  and basal +
white-villous +
swelling +
non-radiate +  and radiate +
well-developed +
5 cm50 mm <br />0.05 m <br /> (25 cm250 mm <br />0.25 m <br />) +
1 +  and 7 +
usually linear +  and lanceolate occasionally ovate +
reduced +
3 cm30 mm <br />0.03 m <br /> (7 cm70 mm <br />0.07 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
spikelike +
Queensland bluegrass +
purple +  and reddish +
ascending +  and erect +
50 cm500 mm <br />0.5 m <br /> (120 cm1,200 mm <br />1.2 m <br />) +
not woody +
Pacific Islands (Hawaii) +, Fla. +, Tex. +  and Miss. +
capillary +
sometimes longer +
concealing +
compressed +  and terete +
shorter or longer +
subtending +
compressed +  and rounded +
unequal +
terete;slightly flattened +
papillose-based +
uncinate +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
bracteate +  and ebracteate +
pedunculate +  and multiple-stalked +
solid +  and hollow +
photosynthetic +
aromatic +
coriaceous +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
membranous +
inconspicuous +
broadly convex +  and slightly concave +
3 cm30 mm <br />0.03 m <br /> (?) +
complex +  and simple +
concealed +  and prominent +
pedicellate +
heterogamous +  and homogamous +
flattened +  and terete to somewhat +
dry +  and fleshy +
elongate +
subdigitate +  and digitate +
Introduced +
pedicellate +  and sessile +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
2 +, 1 +  and many +
sterile +  and bisexual +
compressed +
usually smaller +  and reduced +
3 cm30 mm <br />0.03 m <br /> (?) +
1mm +  and 1.4mm +
1 +  and 3 +
extensive +
fused +  and free +
2 +  and 3 +
dome--shaped +  and triangular +
Gramineae +
Dichanthium sericeum +
Dichanthium +
species +
membranous +
sessile-pedicellate +
bisexual +  and sterile +
perennial +  and annual +
plant +  and cespitose +
aquatic +  and terrestrial +
dioecious +, monoecious +  and synoecious +