Arthraxon hispidus

(Thunb.) Makino
Common names: Jointhead Small carpetgrass
Introduced
Treatment appears in FNA Volume 25. Treatment on page 677.

Plants annual. Culms 0.5-1 (2) m, weak, often decumbent and rooting at the lower nodes; nodes hispid. Leaves cauline; sheaths usually shorter than the internodes; ligules 0.4-3.5 mm, ciliate; lower blades 1-7.5 cm long, 4-20 mm wide, cordate-clasping, ovate to ovatelanceolate, flat, margins ciliate (sometimes sparingly so), surfaces usually glabrous, abaxial surface rarely hispidulous; upper blades greatly reduced. Panicles 1.3-7 cm, flabellate or contracted, with 12-20 rames; rames 1-6 (11) cm. Sessile spikelets: glumes 3-5.5 mm, lanceolate; lower glumes several-veined; upper glumes 1-veined or 3-veined; awns 0.3-9 mm, included or exserted, usually twisted below, sometimes geniculate at midlength; anthers usually 2, 0.5-0.7 mm. Pedicels absent or to 2 mm. Pedicellate spikelets absent. 2n = 36.

Distribution

Del., W.Va., Pacific Islands (Hawaii), N.J., N.Y., Fla., Tex., La., Tenn., N.C., S.C., Pa., Va., Ind., Ohio, Ala., Miss., Ark., Ill., Ga., Mass., Md., Okla., D.C., Oreg., Mo., Kans., Ky.

Discussion

Arthraxon hispidus is native to Asia, but is naturalized and spreading along roadsides, shores, ditches and in low woods and fields of the eastern United States. It is also naturalized in Mexico, Central America, and the West Indies. Plants in the Flora region belong to A. hispidus (Thunb.) Makino var. hispidus, the most widespread and variable of the four varieties. Arthraxon castratus (Griff.) V. Naray. ex Bor reported from Puerto Rico, differs from A. hispidus in having pilose lemma margins, a palea in its second floret, and three anthers.

Selected References

None.

Lower Taxa

None.

"decumbent" is not a number."elongated" is not a number.

... more about "Arthraxon hispidus"
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.07 cm0.7 mm <br />7.0e-4 m <br />) +
anatomy +  and kranz +
John W. Thieret +
(Thunb.) Makino +
1 (?) +  and 3 (?) +
exserted +  and included +
geniculate +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.9 cm9 mm <br />0.009 m <br />) +
keeled +  and rounded +
pseudopetiolate +  and branching +
divergent +  and parallel +
intravaginal +, extravaginal +, branching +  and basal +
swelling +
pseudopetiolate +
non-radiate +  and radiate +
well-developed +
ovate +  and ovatelanceolate +
reduced +
spikelike +
Jointhead +  and Small carpetgrass +
purple +  and reddish +
ascending +  and decumbent +
50 cm500 mm <br />0.5 m <br /> (100 cm1,000 mm <br />1 m <br />) +
not woody +
Del. +, W.Va. +, Pacific Islands (Hawaii) +, N.J. +, N.Y. +, Fla. +, Tex. +, La. +, Tenn. +, N.C. +, S.C. +, Pa. +, Va. +, Ind. +, Ohio +, Ala. +, Miss. +, Ark. +, Ill. +, Ga. +, Mass. +, Md. +, Okla. +, D.C. +, Oreg. +, Mo. +, Kans. +  and Ky. +
capillary +
sometimes longer +
concealing +
compressed +  and terete +
shorter or longer +
subtending +
lanceolate +
subequal +
0.3 cm3 mm <br />0.003 m <br /> (0.55 cm5.5 mm <br />0.0055 m <br />) +
papillose-based +
uncinate +
bracteate +  and ebracteate +
pedunculate +  and multiple-stalked +
photosynthetic +
not aromatic +
coriaceous +
ciliate +  and fimbriate +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
membranous +
inconspicuous +
1 cm10 mm <br />0.01 m <br /> (7.5 cm75 mm <br />0.075 m <br />) +
4mm +  and 20mm +
complex +  and simple +
concealed +  and prominent +
sessile-pedicellate +  and heteromorphic +
11 cm110 mm <br />0.11 m <br /> (?) +
flabellate +
1 cm10 mm <br />0.01 m <br /> (6 cm60 mm <br />0.06 m <br />) +
not fused +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
dry +  and fleshy +
elongate +
Introduced +
pedicellate +  and sessile +
in triplets +  and paired +
usually smaller +  and reduced +
1 (?) +  and 3 (?) +
fused +  and free +
2 (?) +  and 3 (?) +
dome--shaped +  and triangular +
Gramineae +
Arthraxon hispidus +
Arthraxon +
species +
membranous +
sessile-pedicellate +
3-veined +  and 1-veined +
aquatic +  and terrestrial +
dioecious +, monoecious +  and synoecious +