Rhynchospora capitellata

(Michaux) Vahl

Enum. Pl. 2: 235. 1805.

Common names: Rhynchospore à petites têtes
IllustratedEndemic
Basionym: Schoenus capitellatus Michaux Fl. Bor.-Amer. 1: 36. 1803
Synonyms: Phaeocephalum glomeratum var. minus (Britton) Farwell Rhynchospora capitellata var. leptocarpa (Chapman ex Britton) S. F. Blake Rhynchospora capitellata var. minor (Britton) S. F. Blake Rhynchospora glomerata var. minor Britton Rhynchospora leptocarpa
Treatment appears in FNA Volume 23. Treatment on page 210. Mentioned on page 202, 211, 214.
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Plants perennial, cespitose, 20–100 cm; rhizomes absent. Culms arching-ascending, leafy, obtusely trigonous, slender; principal leaves overtopped by inflorescence; blades flat, to 3 mm, apex tapering, trigonous. Inflorescences terminal and axillary, clusters 1–5 or more, compact, turbinate or hemispheric, 1–1.5 cm wide; peduncles progressively shorter distally on culm; bracteal leaves mostly exceeding subtended compounds. Spikelets rich deep brown, rarely pale-brown, lanceellipsoid, 3.5–4 (–5) mm; fertile scale elliptic, 2.7–3 mm, apex acute or rounded, midrib shortexcurrent or not. Flowers: perianth absent. Fruits (1–) 2–3 (–5) per spikelet, (2–) 2.5–3 mm; body redbrown with pale central disc, stipitate, lenticular, obovoid, 1.2–1.5 × 0.7–1 (–1.2) mm, margins pale, wirelike, surfaces slick; tubercle triangularsubulate, (0.8–) 1–1.2 (–1.6) mm.


Phenology: Fruiting summer–fall.
Habitat: Moist to wet meadows, swales, seeps, stream banks, flatwoods, fens, and bogs
Elevation: 0–1600 m

Distribution

V23 361-distribution-map.jpg

N.B., N.S., Ont., Que., Ala., Ark., Calif., Conn., Del., D.C., Fla., Ga., Ill., Ind., Kans., Ky., La., Maine, Md., Mass., Mich., Minn., Miss., Mo., N.H., N.J., N.Y., N.C., Ohio, Oreg., Pa., R.I., S.C., Tenn., Tex., Vt., Va., W.Va., Wis.

Discussion

Rhynchospora capitellata occurs infrequently in the lower Gulf coastal plain (in Florida, only north) and intergrades with R. glomerata. Forms with antrorsely barbellate bristles are referred to forma controversa (S. F. Blake) Gale; those with smooth bristles are named forma discutiens (C. B. Clarke) Gale (S. Gale 1944). Occasional forms with trigonous fruits occur.

Bruce Sorrie (pers. comm.) believes that many of the southern coastal plain records for Rhynchospora capitellata are based on examples of a neglected taxon, R. leptocarpa (Chapman) Small (J. K. Small 1933), and he wishes to reinstate it. Occurring in semi-shady moist sites in steepheads, or from seeps and shallows along blackwater streams, the plants are mostly distinguished by the tall, lax habit; the many distant, small clusters of light brown or tan spikelets; and the softer, more lax foliage. Measures of spikelets, fertile scales, perianth, achenes, and fruit tubercles show a strong overlap with those of southern examples of R. capitellata. The long, lax culm habit, the softer and paler foliage, and the paler spikelets could well be ecologic responses, or the plants could indeed represent a geographic variant.

Selected References

None.

Lower Taxa

None.

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

... more about "Rhynchospora capitellata"
rounded;acute;trigonous;tapering +
Robert Kral +
(Michaux) Vahl +
2-lobed +  and lunate +
Schoenus capitellatus +
scabridulous +  and scabrid +
v--shaped +
0 cm0 mm <br />0 m <br /> (?) +  and 0.3 cm3 mm <br />0.003 m <br /> (?) +
0.1 cm1 mm <br />0.001 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
warty +, papillate +, alveolate +  and pitted +
obovoid +  and lenticular +
0.07 cm0.7 mm <br />7.0e-4 m <br /> (0.1 cm1 mm <br />0.001 m <br />) +
glumaceous +  and foliaceous +
2-ranked +  and arranged +
ascending +  and appressed +
parallel +  and divergent +
terete +, rolled +  and plicate +
Rhynchospore à petites têtes +
arching-ascending +
trigonous +
slender +
N.B. +, N.S. +, Ont. +, Que. +, Ala. +, Ark. +, Calif. +, Conn. +, Del. +, D.C. +, Fla. +, Ga. +, Ill. +, Ind. +, Kans. +, Ky. +, La. +, Maine +, Md. +, Mass. +, Mich. +, Minn. +, Miss. +, Mo. +, N.H. +, N.J. +, N.Y. +, N.C. +, Ohio +, Oreg. +, Pa. +, R.I. +, S.C. +, Tenn. +, Tex. +, Vt. +, Va. +, W.Va. +  and Wis. +
0–1600 m +
distalmost +
0.2 cm2 mm <br />0.002 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
0.25 cm2.5 mm <br />0.0025 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
biconvex +  and trigonous +
Moist to wet meadows, swales, seeps, stream banks, flatwoods, fens, and bogs +
hemispheric +  and turbinate +
1 cm10 mm <br />0.01 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
erect +, rarely +  and spreading +
3-ranked +  and polystichous +
cauline +  and basal +
wirelike +
revolute +  and involute +
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 (?) +
adventitious +
basal +  and proximal +
2-keeled +
0.27 cm2.7 mm <br />0.0027 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
cylindric +
Illustrated +  and Endemic +
2 +  and 3 +
septate +, hollow +  and solid +
compressed +, terete +  and trigonous +
papillate +
cleft +, 2-fid +  and undivided +
Phaeocephalum glomeratum var. minus +, Rhynchospora capitellata var. leptocarpa +, Rhynchospora capitellata var. minor +, Rhynchospora glomerata var. minor +  and Rhynchospora leptocarpa +
Rhynchospora capitellata +
Rhynchospora +
species +
sulcate +  and 2-edged +
0.12 cm1.2 mm <br />0.0012 m <br /> (0.16 cm1.6 mm <br />0.0016 m <br />) +
flattened +, terete +, triangular +  and conic +
0.1 cm1 mm <br />0.001 m <br /> (0.12 cm1.2 mm <br />0.0012 m <br />) +
plant +  and cespitose +