Amphibromus nervosus

(Hook, f.) Baill.
Common names: Common swamp wallabygrass
Treatment appears in FNA Volume 24. Treatment on page 704.
Please click on the illustration for a higher resolution version.
Illustrator: Bee F. Gunn

Copyright: Utah State University

Plants perennial; usually cespitose, occasionally rhizomatous. Culms 30-125 cm tall, 1-3 mm thick, erect, terete to flattened, glabrous; nodes 2-5; lowest internodes not swollen. Sheaths smooth or scabridulous, ribbed; ligules 10-20 mm, acute to acuminate; blades 10-30 cm long, 1.5-3.5 mm wide, flat or involute, smooth to scabrous, abaxial surfaces scabridulous, adaxial surfaces deeply ribbed, scabrous. Terminal panicles 15-40 cm, erect, sparse, the lower portion sometimes partially enclosed in the uppermost sheaths; branches usually 7-15 cm, ascending or appressed, often flexuous; pedicels usually 10-20 mm. Spikelets 10-16 mm, with 4-6 florets. Glumes unequal to subequal, green, sometimes purplish in the center, with hyaline margins; lower glumes 2.5-5.5 mm, 3-5-veined; upper glumes 3-6.5 mm, 3-5-veined; lemmas 5-7.2 mm, 5-7-veined, scabrous, apices not appearing constricted, usually 4-toothed, 2 lateral teeth smaller than the 2 central teeth, awned from the lower 2/5 – 3/5 of the lemmas, awns 12-22 mm, geniculate and twisted; paleas 3/4 as long as to subequal to the lemmas, papillose; anthers of chasmogamous florets 2.2-3 mm, those of cleistogamous florets 0.3-1.4 mm. 2n = unknown.

Discussion

Amphibromus nervosus is the most common species in the genus. It has frequently been misidentified as A. neesii, but has a lower awn insertion. Such misidentification is the basis of the report of A. neesii in North America; examination of the voucher specimens showed them to be A. nervosus. They were collected in 1990 from a vernal pool in Sacramento County, California. Its seeds had been found earlier as a contaminant in Trifolium subterraneum seed being imported from Australia. The discovery of living plants is of particular concern, because of their ability to invade and survive in vernal pools.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

... more about "Amphibromus nervosus"
membranous +  and scarious +
midlength +
Surrey W.L. Jacobs +
(Hook, f.) Baill. +
1 (?) +  and 3 (?) +
straight +
recurved +, spreading +  and arising +
basal +  and terminal +
geniculate +
1.2 cm12 mm <br />0.012 m <br /> (2.2 cm22 mm <br />0.022 m <br />) +
keeled +  and rounded +
pseudopetiolate +  and branching +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
10 cm100 mm <br />0.1 m <br /> (30 cm300 mm <br />0.3 m <br />) +
not evident +
smooth to scabrous +
involute +  and flat +
1.5mm;3.5mm +
appressed;ascending +
spikelike +
Common swamp wallabygrass +
not branching +
30 cm300 mm <br />0.3 m <br /> (125 cm1,250 mm <br />1.25 m <br />) +
terete +  and flattened +
0 cm0 mm <br />0 m <br /> (180 cm1,800 mm <br />1.8 m <br />) +
not woody +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
pistillate +  and staminate +
Calif. +  and La. +
1/4 +  and 1/3 +
liquid +, soft +  and hard +
capillary +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.14 cm1.4 mm <br />0.0014 m <br />) +
pistillate +  and staminate +
sometimes longer +
4 +  and 6 +
cleistogamous +  and chasmogamous +
compressed +
reduced +
purplish +  and green +
shorter or longer +
subtending +
acute +  and obtuse +
unequal +  and subequal +
uncinate +
0 +  and 1/2 +
lanceolate +  and ovate +
0.5 cm5 mm <br />0.005 m <br /> (0.72 cm7.2 mm <br />0.0072 m <br />) +
acute +  and acuminate +
1 cm10 mm <br />0.01 m <br /> (2 cm20 mm <br />0.02 m <br />) +
membranous +
2 (?) +  and ? (?) +
aristate +  and obtuse +
inconspicuous +
not lobed +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.55 cm5.5 mm <br />0.0055 m <br />) +
shorter and narrower +
concealed +  and prominent +
2 +  and 5 +
2 +  and 1 +
well-developed +
papillose +
2-keeled +
subequal +
cleistogamous +
spikelike +
1 cm10 mm <br />0.01 m <br /> (2 cm20 mm <br />0.02 m <br />) +
dry +  and fleshy +
terminating in a reduced floret +  and empty +
scabridulous +  and smooth +
1 +  and 60 +
compressed +
1 cm10 mm <br />0.01 m <br /> (1.6 cm16 mm <br />0.016 m <br />) +
1 (?) +  and 3 (?) +
simple +  and compound +
2 (?) +  and 3 (?) +
Gramineae +
Amphibromus nervosus +
Amphibromus +
species +
15 cm150 mm <br />0.15 m <br /> (40 cm400 mm <br />0.4 m <br />) +
membranous +
2 +  and 4 +
0.3 cm3 mm <br />0.003 m <br /> (0.65 cm6.5 mm <br />0.0065 m <br />) +
parallel +  and converging +
5 +  and 9 +
plant +  and cespitose +
aquatic +  and terrestrial +