Rhynchospora decurrens

Chapman

Fl. South. U.S., 525. 1860.

IllustratedEndemic
Synonyms: Phaeocephalum decurrens (Chapman) House
Treatment appears in FNA Volume 23. Treatment on page 226. Mentioned on page 205, 227.
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Plants perennial, cespitose, to 100 cm; rhizomes sometimes produced, short, not stoloniferous. Culms lax, erect to ascending-excurved, ± terete, leafy, slender, soft. Leaves exceeded by inflorescence; blades erect or ascending, linear, proximally flat, 2–4 mm wide, apex trigonous, subulate, tapering. Inflorescences: spikelet clusters 4–6, widely spaced, loose, broadly to narrowly turbinate, paniculate, branches capillary, ultimate branches with 1 or 2 spikelets; leafy bracts exceeding proximal clusters, setaceous. Spikelets solitary or in 2s, brown, ovoid, 2.5–3.5 mm; fertile scales ovate, 1.5–2.2 mm, apex acute, apiculate. Flowers: perianth bristles 6, reaching tubercle base or slightly beyond, antrorsely barbellate. Fruits 2–3 per spikelet, 1.5–1.6 (–1.8) mm; body brown or greenish, obovoid, lenticular, 1.1–1.2 (–1.3) × 0.7–1 mm, margins narrow, distinct, sharp, flowing to tubercle; surfaces finely transversely wavyrugulose, intervals of fine, nearly isodiametric or vertical-rectangular pitlike alveolae; tubercle lowtriangular, entire, 0.3–0.4 mm.


Phenology: Fruiting late spring–summer.
Habitat: Sandy alluvium of swamp forests and environs
Elevation: 0–100 m

Distribution

V23 398-distribution-map.jpg

Ala., Fla., Ga., La., Miss., N.C., S.C.

Discussion

Rhynchospora decurrens superficially resembles R. mixta, with which it is often associated in swamp forests. Its narrower fruit bodies with less distinct transverse rugosity; the smaller, more numerous rows of finer, pitlike alveolae; and its broader, lower tubercles with non-setose edges all comprise consistent differences. The name decurrens is apt, calling attention to the narrow, wirelike pale margins that extend from tubercle base to near the base of the fruit body.

Selected References

None.

Lower Taxa

None.

"wider" is not a number.

... more about "Rhynchospora decurrens"
pitlike +, vertical-rectangular +  and isodiametric +
Robert Kral +
Chapman +
shortened +
2-lobed +  and lunate +
scabridulous +  and scabrid +
v--shaped +
2mm;4mm +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.13 cm1.3 mm <br />0.0013 m <br />) +
greenish +  and brown +
0.11 cm1.1 mm <br />0.0011 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
warty +, papillate +, alveolate +  and pitted +
lenticular +  and obovoid +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
ascending +  and appressed +
setaceous +
capillary +
parallel +  and divergent +
terete +, rolled +  and plicate +
erect +  and ascending-excurved +
slender +
Ala. +, Fla. +, Ga. +, La. +, Miss. +, N.C. +  and S.C. +
0–100 m +
distalmost +
0.16 cm1.6 mm <br />0.0016 m <br /> (0.18 cm1.8 mm <br />0.0018 m <br />) +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.16 cm1.6 mm <br />0.0016 m <br />) +
biconvex +  and trigonous +
Sandy alluvium of swamp forests and environs +
racemose +, corymbose +  and paniculate +
erect +, rarely +  and spreading +
3-ranked +  and polystichous +
cauline +  and basal +
revolute +  and involute +
decurrent +
plumed +  and barbed +
deciduous +  and persistent +
shorter or longer +
of 2-12(-20) bristles +
Fruiting late spring–summer. +
2-3(-4)-carpellate +
3 (?) +  and 1 (?) +
Fl. South. U.S., +
not stoloniferous +
adventitious +
basal +  and proximal +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.22 cm2.2 mm <br />0.0022 m <br />) +
cylindric +
Illustrated +  and Endemic +
in 2s , brown , ovoid , 2.5-3.5 mm +  and solitary +
paniculate +, spaced +  and cluster +
turbinate +
2 (?) +  and 3 (?) +
septate +, hollow +  and solid +
compressed +, terete +  and trigonous +
papillate +
cleft +, 2-fid +  and undivided +
wavyrugulose +
Phaeocephalum decurrens +
Rhynchospora decurrens +
Rhynchospora +
species +
sulcate +  and 2-edged +
flattened +, terete +, triangular +  and conic +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.04 cm0.4 mm <br />4.0e-4 m <br />) +
plant +  and cespitose +