Rhynchospora megalocarpa

A. Gray

Ann. Lyceum Nat. Hist. New York 3: 208. 1835.

IllustratedEndemic
Synonyms: Phaeocephalum dodecandrum (Baldwin ex A. Gray) House Rhynchospora dodecrandra Baldwin ex A. Gray Rhynchospora pycnocarpa A. Gray
Treatment appears in FNA Volume 23. Treatment on page 230. Mentioned on page 205, 231.
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Plants perennial, cespitose, to 130 cm, coarse; rhizomes scaly, stoloniferous, stout. Culms erect to arching, leafy, trigonous, slender, firm. Leaves overtopped by culms; blades linear, proximally flat, 3–7 mm wide, apex trigonous, subulate, tapering. Inflorescences: spikelet clusters 2–6, sparse, widely spaced, turbinate; peduncles and branches ascending; leafy bracts exceeding proximal clusters. Spikelets light-redbrown, ovoid to ellipsoid, (4–) 5–8 (–9) mm, apex acute or acuminate; fertile scales ovate, (5.5–) 6–6.5 (–7) mm, midrib included or shortexcurrent. Fruits 1–2 per spikelet, (3.5–) 4–5 mm; body dark-brown to mahogany or nearly black, broadly obovoid, tumid, nearly smooth, buttressed to tubercle; tubercle lowconic, rimmed, 0.7 (–1) mm, apex apiculate. Flowers: perianth bristles 6 (–8), mostly reaching from fruit midbody to tubercle base, antrorsely barbellate.


Phenology: Fruiting summer–fall.
Habitat: White or yellow sandhills
Elevation: 0–300 m

Distribution

V23 406-distribution-map.jpg

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

Discussion

The perianth in Rhynchospora megalocarpa is unusual. The receptacular joint is stubby, bearing staggered cycles of bristles that vary extremely in length and number—on a par with R. alba, R. baldwinii, and R. macra in numbers of bristles. The greatest extreme is twelve, the fewest as low as two; usually if the number is low, the remaining sites for bristles will be dark-colored nubbins.

Selected References

None.

Lower Taxa

None.

"shortened" is not a number."wider" is not a number.

... more about "Rhynchospora megalocarpa"
acuminate;acute;tapering;subulate;trigonous +
Robert Kral +
A. Gray +
2-lobed +  and lunate +
scabridulous +  and scabrid +
v--shaped +
0.3 cm3 mm <br />0.003 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
dark-brown +  and mahogany or nearly black +
warty +, papillate +, alveolate +  and pitted +
tumid +  and obovoid +
ascending +  and appressed +
parallel +  and divergent +
terete +, rolled +  and plicate +
erect +  and arching +
trigonous +
slender +
Ala. +, Fla. +, Ga. +, Miss. +, N.C. +  and S.C. +
0–300 m +
distalmost +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
0.4 cm4 mm <br />0.004 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
biconvex +  and trigonous +
White or yellow sandhills +
racemose +, corymbose +  and paniculate +
erect +, rarely +  and spreading +
3-ranked +  and polystichous +
cauline +  and basal +
keeled;terete;keeled;terete +
revolute +  and involute +
shortexcurrent +  and included +
decurrent +
plumed +  and barbed +
deciduous +  and persistent +
shorter or longer +
of 2-12(-20) bristles +
Fruiting summer–fall. +
2-3(-4)-carpellate +
3 (?) +  and 1 (?) +
Ann. Lyceum Nat. Hist. New York +
stoloniferous +
adventitious +
0.65 cm6.5 mm <br />0.0065 m <br /> (0.7 cm7 mm <br />0.007 m <br />) +
basal +  and proximal +
0.6 cm6 mm <br />0.006 m <br /> (0.65 cm6.5 mm <br />0.0065 m <br />) +
cylindric +
Illustrated +  and Endemic +
spaced +  and cluster +
light-redbrown +
ovoid;ellipsoid +
0.5 cm5 mm <br />0.005 m <br /> (0.8 cm8 mm <br />0.008 m <br />) +
2 +  and 3 +
septate +, hollow +  and solid +
compressed +, terete +  and trigonous +
papillate +
cleft +, 2-fid +  and undivided +
Phaeocephalum dodecandrum +, Rhynchospora dodecrandra +  and Rhynchospora pycnocarpa +
Rhynchospora megalocarpa +
Rhynchospora +
species +
sulcate +  and 2-edged +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
flattened +, terete +, triangular +  and conic +
0.7 cm7 mm <br />0.007 m <br /> (?) +
plant +  and cespitose +