Rhynchospora gracilenta

A. Gray

Ann. Lyceum Nat. Hist. New York 3: 216. 1835.

Illustrated
Basionym: Rhynchospora drummondiana Boeckeler 1858
Synonyms: Phaeocephalum gracilentum (A. Gray) House Rhynchospora gracilenta var. diversifolia Fernald Rhynchospora trichophylla
Treatment appears in FNA Volume 23. Treatment on page 236. Mentioned on page 206, 235.
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Plants perennial, densely cespitose or solitary, 10–100 cm; rhizomes absent. Culms mostly lax, ascending to leaningexcurved, leafy, linear to filiform, terete. Leaves shorter than culm; blades ascending, filiform to narrowly linear, proximally flat, 0.5–1.5 (–2.5) mm wide, margins distally strongly involute, apex trigonous, tapering. Inflorescences: spikelet clusters 1–3 (–4), proximalmost distant, dense to sparse, narrowly turbinate to hemispheric; peduncles and branches ascending; leafy bracts linearsetaceous, mostly overtopping clusters. Spikelets redbrown, ovoid to lanceoloid, (3.5–) 4–5 mm, apex acute; fertile scales ovate, 3–4.5 mm, apex acute, mucronate to awnedcuspidate. Flowers: bristles 6, mostly reaching tip of tubercle or beyond, antrorsely barbellate. Fruits 1–3 per spikelet, (2.5–) 3–3.5 (–4.1) mm; body dark-brown with small pale center, lenticular, broadly ellipsoid to suborbicular, 1.3–2.1 × 1.3–1.5 mm, smooth, margins narrow, flowing into tubercle; tubercle triangularsubulate, compressed, mostly 1.5–2 mm.


Phenology: Fruiting late spring–fall.
Habitat: Moist to wet sandy peaty substrates in ditches, bogs, seeps, wet savannas, barrens, and flatwoods
Elevation: 0–400 m

Distribution

V23 420-distribution-map.jpg

Ala., Ark., Del., Fla., Ga., La., Md., Miss., N.J., N.C., Okla., Pa., S.C., Tenn., Tex., Va., West Indies (Cuba), Central America

Discussion

Through the southern coastal plain are widerleaved examples of Rhynchospora gracilenta that are sparingly cespitose to solitary-stemmed, often with but a single terminal inflorescence with dense clusters of spikelets (var. diversifolia). That would be a tenable designation were it not for the large numbers of populations with intermediate habit.

Selected References

None.

Lower Taxa

None.

"wider" is not a number.

... more about "Rhynchospora gracilenta"
Robert Kral +
A. Gray +
shortened +
2-lobed +  and lunate +
Rhynchospora drummondiana +
scabridulous +  and scabrid +
filiform +  and narrowly linear +
0.5mm;1.5mm +
dark-brown +
0.13 cm1.3 mm <br />0.0013 m <br /> (0.21 cm2.1 mm <br />0.0021 m <br />) +
warty +, papillate +, alveolate +  and pitted +
broadly ellipsoid +  and suborbicular +
0.13 cm1.3 mm <br />0.0013 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
ascending +  and appressed +
parallel +  and divergent +
terete +, rolled +  and plicate +
terete +, linear +  and filiform +
Ala. +, Ark. +, Del. +, Fla. +, Ga. +, La. +, Md. +, Miss. +, N.J. +, N.C. +, Okla. +, Pa. +, S.C. +, Tenn. +, Tex. +, Va. +, West Indies (Cuba) +  and Central America +
0–400 m +
distalmost +
0.35 cm3.5 mm <br />0.0035 m <br /> (0.41 cm4.1 mm <br />0.0041 m <br />) +
0.3 cm3 mm <br />0.003 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
biconvex +  and trigonous +
Moist to wet sandy peaty substrates in ditches, bogs, seeps, wet savannas, barrens, and flatwoods +
racemose +, corymbose +  and paniculate +
erect +, rarely +  and spreading +
3-ranked +  and polystichous +
cauline +  and basal +
keeled;terete;keeled;terete +
decurrent +
plumed +  and barbed +
deciduous +  and persistent +
shorter or longer +
of 2-12(-20) bristles +
Fruiting late spring–fall. +
2-3(-4)-carpellate +
3 (?) +  and 1 (?) +
Ann. Lyceum Nat. Hist. New York +
adventitious +
basal +  and proximal +
0.3 cm3 mm <br />0.003 m <br /> (0.45 cm4.5 mm <br />0.0045 m <br />) +
cylindric +
Illustrated +
ovoid;lanceoloid +
0.4 cm4 mm <br />0.004 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
2 (?) +  and 3 (?) +
septate +, hollow +  and solid +
compressed +, terete +  and trigonous +
papillate +
cleft +, 2-fid +  and undivided +
Phaeocephalum gracilentum +, Rhynchospora gracilenta var. diversifolia +  and Rhynchospora trichophylla +
Rhynchospora gracilenta +
Rhynchospora +
species +
sulcate +  and 2-edged +
compressed +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
plant +, solitary +  and cespitose +