Najas filifolia

R. R. Haynes

Brittonia 37: 392. 1985.

IllustratedEndemicConservation concern
Treatment appears in FNA Volume 22.

Stems profusely branched distally to proximally, 7–22 cm × 0.2–1 mm; internodes 0.2–4 cm, without prickles. Leaves usually recurved with age, 0.8–2.6 cm, lax stiff in age; sheath 1–1.3 mm wide, apex round to slightly auriculate; blade 0.1–0.7 mm wide, margins conspicuously serrulate, teeth 5–9 per side, apex acute, with 1 tooth, teeth multicellular; midvein without prickles abaxially. Flowers 1 per axil, staminate and pistillate on same plants. Staminate flowers in distal axils, 2–3 mm; involucral beaks 4-lobed, 0.4–0.6 mm; anthers 4-loculed, 1.5–2 mm. Pistillate flowers in proximal axils, to 2.5 mm; styles less than 0.4 mm; stigmas 4-lobed. Seeds strongly recurved, greenish brown, fusiform, 2.5–3 × 0.5–0.7 mm, apex with style situated at centeral; testa dull, 3 cell-layers thick, pitted; aeroleareoles regularly arranged in ca. 20 longitudinal rows, not ladderlike, 4-angled, longer than broad, end walls raised. Chromosome number unknown not available.


Phenology: Flowering late summer.
Habitat: Sandy- bottomed lakes
Elevation: 0–100 m

Discussion

Najas filifolia is known from four localities: Open Pond and Cane Water Pond in Decatur County, Georgia; Milton in Santa Rosa County, Florida; and Lake Jackson in Leon County, Florida.

The vegetative organs of Najas filifolia resemble those of N. minor and N. wrightiana by the presence of large teeth scattered along the margin of quite narrow leaves. Najas filifolia is easily distinguished from the latter two species, however, by its recurved fruits (sometimes crescent-shaped). I know of no other Najas with such curved fruits.

The name Najas conferta A. Braun has been misapplied to this taxon.

Of conservation concern.

Selected References

None.

Lower Taxa

None.

"elongating" is not a number.

... more about "Najas filifolia"
0.15 cm1.5 mm <br />0.0015 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
acute +, round +  and slightly auriculate +
Robert R. Haynes +
R. R. Haynes +
involucral +
4-lobed +
0.04 cm0.4 mm <br />4.0e-4 m <br /> (0.06 cm0.6 mm <br />6.0e-4 m <br />) +
armed +  and 1-veined +
0.01 cm0.1 mm <br />1.0e-4 m <br /> (0.07 cm0.7 mm <br />7.0e-4 m <br />) +
sharp-tipped +
short-pedunculate +  and sessile +
Fla. +  and Ga. +
0–100 m +
pistillate +  and staminate +
0 cm0 mm <br />0 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
Sandy- bottomed lakes +
0.2 cm2 mm <br />0.002 m <br /> (4 cm40 mm <br />0.04 m <br />) +
light green +  and brown +
red-purple +  and purple +
whorled +, appearing +  and opposite +
submersed +
0.8 cm8 mm <br />0.008 m <br /> (2.6 cm26 mm <br />0.026 m <br />) +
serrate to minutely +
Flowering late summer. +
not stipitate +
longer than broad +
4-angled +  and not ladderlike +
auriculate +  and not auriculate +
greenish brown +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
fusiform +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.07 cm0.7 mm <br />7.0e-4 m <br />) +
not persisting +
variously--shaped +
1mm;1.3mm +
Illustrated +, Endemic +  and Conservation concern +
7 cm70 mm <br />0.07 m <br /> (22 cm220 mm <br />0.22 m <br />) +
slender +
0.2mm;1mm +
2-4-branched +
0 cm0 mm <br />0 m <br /> (0.04 cm0.4 mm <br />4.0e-4 m <br />) +
Najas filifolia +
species +
multicellular +
caulescent +  and not rhizomatous +
perennial +  and annual +