Amphibromus neesii

Steud.
Common names: Southern 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 30-150 cm tall, 1-2.5 mm thick, erect, terete to flattened, glabrous; nodes 2-4; lowest internodes not swollen. Sheaths smooth or scabridulous, ribbed; ligules 4.5-8 mm, acute to acuminate; blades 10-20 (37) cm long, 2-4 mm wide, flat or involute, smooth to scabrous, abaxial surfaces scabridulous, adaxial surfaces deeply ribbed, scabrous. Terminal panicles 15-40 cm, erect, sparse, lower portion rarely partially enclosed in the uppermost sheaths; branches usually 7-14 cm, ascending or appressed, often flexuous; pedicels usually 10-20 mm. Spikelets 8-17 mm, with 2-6 florets. Glumes unequal, green, sometimes purplish in the center, with hyaline margins; lower glumes 3.5-6.5 mm, 3-5-veined; upper glumes 4.5-7.5 mm, 5-7-veined; lemmas 5-8.4 mm, 7-veined, papillose to scabrous, apices appearing constricted, 2-4-toothed, awned from the upper 2/3 - 3/4 of the lemmas, awns 14-26 mm, geniculate and twisted; paleas 8/10 – 9/10 the length of the lemmas, papillose; anthers of chasmogamous florets 1.3-2.3 mm. 2n = unknown.

Discussion

Amphibromus neesii is an Australian species that grows on floodplains and river banks, and in marshes and lagoons. It was first reported as growing in North America in 1990; examination of the voucher specimens showed them to be A. nervosus, which differs from A. neesii in having a lower lemma awn insertion. Both species are included in this treatment to help prevent future misidentification of the two species in North America.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number.

... more about "Amphibromus neesii"
membranous +  and scarious +
midlength +
Surrey W.L. Jacobs +
Steud. +
1 (?) +  and 3 (?) +
straight +
recurved +, spreading +  and arising +
basal +  and terminal +
geniculate +
1.4 cm14 mm <br />0.014 m <br /> (2.6 cm26 mm <br />0.026 m <br />) +
keeled +  and rounded +
pseudopetiolate +  and branching +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
10 cm100 mm <br />0.1 m <br /> (20 cm200 mm <br />0.2 m <br />) +
not evident +
smooth to scabrous +
involute +  and flat +
2mm;4mm +
appressed;ascending +
spikelike +
Southern swamp wallabygrass +
not branching +
30 cm300 mm <br />0.3 m <br /> (150 cm1,500 mm <br />1.5 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 /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
pistillate +  and staminate +
1/4 +  and 1/3 +
liquid +, soft +  and hard +
capillary +
0.13 cm1.3 mm <br />0.0013 m <br /> (0.23 cm2.3 mm <br />0.0023 m <br />) +
pistillate +  and staminate +
sometimes longer +
2 +  and 6 +
compressed +
reduced +
purplish +  and green +
shorter or longer +
subtending +
acute +  and obtuse +
unequal +
uncinate +
0 +  and 1/2 +
papillose +  and scabrous +
lanceolate +  and ovate +
0.5 cm5 mm <br />0.005 m <br /> (0.84 cm8.4 mm <br />0.0084 m <br />) +
acute +  and acuminate +
0.45 cm4.5 mm <br />0.0045 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
membranous +
2 (?) +  and 4 (?) +
aristate +  and obtuse +
inconspicuous +
not lobed +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.65 cm6.5 mm <br />0.0065 m <br />) +
shorter and narrower +
concealed +  and prominent +
2 +  and 4 +
2 +  and 1 +
well-developed +
8/10 +  and 9/10 +
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 +
0.8 cm8 mm <br />0.008 m <br /> (1.7 cm17 mm <br />0.017 m <br />) +
1 (?) +  and 3 (?) +
simple +  and compound +
2 (?) +  and 3 (?) +
Gramineae +
Amphibromus neesii +
Amphibromus +
species +
15 cm150 mm <br />0.15 m <br /> (40 cm400 mm <br />0.4 m <br />) +
membranous +
2 +  and 4 +
0.45 cm4.5 mm <br />0.0045 m <br /> (0.75 cm7.5 mm <br />0.0075 m <br />) +
parallel +  and converging +
5 +  and 9 +
plant +  and cespitose +
aquatic +  and terrestrial +