Rhynchospora nivea

Boeckeler

Linnaea 37: 527. 1872.

IllustratedEndemic
Synonyms: Dichromena diphylla Torrey Dichromena nivea (Boeckeler) Britton
Treatment appears in FNA Volume 23. Treatment on page 216. Mentioned on page 215.
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Plants perennial, cespitose, 10–40 cm, wiry; rhizomes absent. Culms erect to spreadingascending, leafybased, trigonous or compressed, ribbed. Leaves exceeded by scape; blades narrowly linear to filiform, 0.2–2 mm wide, apex tapering, trigonous. Inflorescences terminal, solitary, headlike, dense, white, leafyinvolucrate, hemispheric to globose, 0.5–1.5 cm wide; involucral-bracts (0–) 1–4, ascending to recurved, green, (0.7–) 2–5 (–6) cm × 0.2–2 mm. Spikelets white, ovoid, 5–7 mm; fertile scales several, boatshaped, 2.5–3.5 mm, keel curved, not sharp. Flowers: perianth absent. Fruits 0.8–1 mm; body yellow to near black, broadly pyriformobovoid, tumidly lenticular, 0.5–0.8 × 0.5–0.8 mm, margin narrow, flowing into tubercle; surfaces transversely sharply wavyrugose, ridges bordered by rows of fine, linear, vertical lattices; tubercle depressedtriangular, lunate-based, shortbeaked 0.2 (–0.3) mm, graycrustaceous.


Phenology: Fruiting spring–fall.
Habitat: Low, open, moist to wet, basic substrates of fens, meadows, seeps, and shores, limestone districts
Elevation: 0–500 m

Discussion

Rhynchospora nivea, of the “Dichromena” of North America, is the smallest fruited and most slender and has the fewest and shortest involucral bracts (in some plants the bract is entirely absent). Involucral bracts of R. nivea are almost entirely green.

Selected References

None.

Lower Taxa

None.

"wider" is not a number.

... more about "Rhynchospora nivea"
Robert Kral +
Boeckeler +
shortened +
2-lobed +  and lunate +
scabridulous +  and scabrid +
narrowly linear +  and filiform +
0.2mm;2mm +
warty +, papillate +, alveolate +  and pitted +
ridged +, terete +, lenticular +  and flattened +
glumaceous +  and foliaceous +
2-ranked +  and arranged +
ascending +  and appressed +
parallel +  and divergent +
terete +, rolled +  and plicate +
compressed +  and trigonous +
Okla. +  and Tex. +
0–500 m +
distalmost +
0.08 cm0.8 mm <br />8.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
biconvex +  and trigonous +
Low, open, moist to wet, basic substrates of fens, meadows, seeps, and shores, limestone districts +
racemose +, corymbose +  and paniculate +
hemispheric +  and globose +
5 cm50 mm <br />0.05 m <br /> (6 cm60 mm <br />0.06 m <br />) +
2 cm20 mm <br />0.02 m <br /> (?) +  and 5 cm50 mm <br />0.05 m <br /> (?) +
ascending +  and recurved +
3-ranked +  and polystichous +
cauline +  and basal +
0.5mm;0.8mm +
lenticular +
revolute +  and involute +
0.5mm +  and 0.8mm +
decurrent +
plumed +  and barbed +
deciduous +  and persistent +
shorter or longer +
of 2-12(-20) bristles +
Fruiting spring–fall. +
2-3(-4)-carpellate +
3 (?) +  and 1 (?) +
adventitious +
basal +  and proximal +
boat-shaped +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
cylindric +
Illustrated +  and Endemic +
1 +, 3 +  and 100 +
0.5 cm5 mm <br />0.005 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
2 (?) +  and 3 (?) +
septate +, hollow +  and solid +
compressed +, terete +  and trigonous +
papillate +
cleft +, 2-fid +  and undivided +
wavyrugose +
Dichromena diphylla +  and Dichromena nivea +
Rhynchospora nivea +
Rhynchospora +
species +
0.02 cm0.2 mm <br />2.0e-4 m <br /> (0.03 cm0.3 mm <br />3.0e-4 m <br />) +
flattened +, terete +, triangular +  and conic +
0.2 cm2 mm <br />0.002 m <br /> (?) +
plant +  and cespitose +