Najas graminea

Delile

Description de l'Egypte... Histoire Naturelle 282, plate 50, fig. 3. 1813.

WeedyIntroduced
Treatment appears in FNA Volume 22.

Stems sparingly branched distally, to 35 cm × 0.2–0.5 mm; internodes 0.4–1.9 cm, without prickles. Leaves spreading to ascending with age, 0.8–2 cm, lax in age; sheath 1–1.5 mm wide, apex deeply auriculate; blade 0.5–1 mm wide, margins minutely serrulate, teeth 40 per side, apex acute with 2–3 teeth, teeth unicellular; midvein without prickles abaxially. Flowers 1–2 per axil, staminate and pistillate on same plants. Staminate flowers in distal axils, 2–3 mm; involucre beaks 4-lobed, 1–1.5 mm; anther 4-loculed, 1.5 mm. Pistillate flowers distal to proximal, to 3.5 mm; styles to 1 mm; stigmas 2-lobed. Seeds not recurved, greenish brown, fusiform, 1.7–2.5 × 0.4–6 mm, apex with style situated at center; testa dull, 3 cell-layers thick, pitted; aeroleareoles regularly arranged in 35 longitudinal rows, not ladderlike, 4-angled, as long aser than broad, end walls slightly raised. 2n = 24, 36, 48 (Asia).


Phenology: Flowering summer.
Habitat: Rice fields
Elevation: 200 m

Distribution

V22 349-distribution-map.jpg

Introduced; Calif., Eurasia, Africa, Australia

Discussion

Because of the deeply auriculate sheaths, Najas graminea is one of the easiest of the North American and Central American Najas to recognize. Najas graminea often becomes weedy in rice fields of southeast Asia.

Selected References

None.

Lower Taxa

None.

"elongating" is not a number.

... more about "Najas graminea"
48 +, 36 +  and 24 +
1.5 cm15 mm <br />0.015 m <br /> (?) +
acute +  and auriculate +
Robert R. Haynes +
Delile +
armed +  and 1-veined +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
sharp-tipped +
short-pedunculate +  and sessile +
Calif. +, Eurasia +, Africa +  and Australia +
pistillate +  and staminate +
distal;proximal +
1 +  and 2 +
0 cm0 mm <br />0 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
Rice fields +
0.4 cm4 mm <br />0.004 m <br /> (1.9 cm19 mm <br />0.019 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
light green +  and brown +
red-purple +  and purple +
whorled +, appearing +  and opposite +
submersed +
spreading;ascending +
0.8 cm8 mm <br />0.008 m <br /> (2 cm20 mm <br />0.02 m <br />) +
serrate to minutely +
Flowering summer. +
not stipitate +
Description de l'Egypte... Histoire Naturelle +
4-angled +  and not ladderlike +
auriculate +  and not auriculate +
greenish brown +
0.17 cm1.7 mm <br />0.0017 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
not recurved +
fusiform +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.6 cm6 mm <br />0.006 m <br />) +
not persisting +
variously--shaped +
1mm;1.5mm +
Weedy +  and Introduced +
0 cm0 mm <br />0 m <br /> (35 cm350 mm <br />0.35 m <br />) +
slender +
0.2mm;0.5mm +
2-4-branched +
0 cm0 mm <br />0 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
Najas graminea +
species +
caulescent +  and not rhizomatous +
perennial +  and annual +