Rhynchospora brachychaeta

C. Wright

Anales Real Acad. Ci. Méd. Fís. Nat. Habana 8: 85. 1873.

Illustrated
Basionym: Rhynchospora chapmanii Britton 1916 Rhynchospora pallida C. B. Clarke 1900 Rhynchospora pallida Kükenthal 1926
Synonyms: Phaeocephalum brachychaetum (C. Wright) House Rhynchospora blauneri Britton
Treatment appears in FNA Volume 23. Treatment on page 235. Mentioned on page 206.
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Plants perennial, densely cespitose, 20–50 cm; rhizomes absent. Culms erect to excurved, lax, filiform, leafy, ± terete. Leaves exceeded by culm, ascending; blades filiform, ± terete, margins strongly involute, apex trigonous, sulcate, tapering. Inflorescences: spikelet clusters mostly 2–3, sparse to dense, oblong to broadly or narrowly turbinate; leafy bracts setaceous, exceeding clusters. Spikelets pale redbrown, lanceoloid, 3–3.5 mm, apex acute; fertile scales mostly elliptic, 2–2.5 mm, apex acute, sometimes apiculate. Flowers: bristles mere nubs or 1–2, to 0.3 mm. Fruits mostly 2 per spikelet, 1.5–1.6 mm; body redbrown with pale center, lenticular, broadly obovoid to orbicular, margins pale, narrow, flowing to tubercle; surfaces smoothish, or faintly cancellate; tubercle flattened, triangularsubulate, 0.3–0.5 mm.


Phenology: Fruiting late spring–fall.
Habitat: Moist sandy peaty substrates in savannas or savanna bog transition, ditches, and moist, disturbed areas

Distribution

V23 418-distribution-map.jpg

Ala., Fla., Miss., West Indies, Central America

Discussion

Rhynchospora brachychaeta is quite possibly adventive; most of its localities in the flora are in disturbed areas near the coast. It is similar to the widespread native R. chapmanii, from which it is distinguished by its more numerous spikelet clusters, the darker spikelets, the achene faces brown with pale centers (rather than pale with brown ends), and the relatively more developed perianth.

Selected References

None.

Lower Taxa

None.

"wider" is not a number.

... more about "Rhynchospora brachychaeta"
Robert Kral +
C. Wright +
shortened +
2-lobed +  and lunate +
Rhynchospora chapmanii +  and Rhynchospora pallida +
scabridulous +  and scabrid +
terete +  and filiform +
warty +, papillate +, alveolate +  and pitted +
broadly obovoid +  and orbicular +
ascending +  and appressed +
setaceous +
parallel +  and divergent +
terete +, rolled +  and plicate +
terete +, filiform +  and excurved +
Ala. +, Fla. +, Miss. +, West Indies +  and Central America +
distalmost +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.16 cm1.6 mm <br />0.0016 m <br />) +
biconvex +  and trigonous +
Moist sandy peaty substrates in savannas or savanna bog transition, ditches, and moist, disturbed areas +
racemose +, corymbose +  and paniculate +
erect +, rarely +  and spreading +
3-ranked +  and polystichous +
cauline +  and basal +
keeled;terete;keeled;terete +
decurrent +
0 cm0 mm <br />0 m <br /> (0.03 cm0.3 mm <br />3.0e-4 m <br />) +
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 (?) +
Anales Real Acad. Ci. Méd. Fís. Nat. Habana +
adventitious +
basal +  and proximal +
2-keeled +
0.2 cm2 mm <br />0.002 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
cylindric +
Illustrated +
pale redbrown +
sparse +  and dense +
lanceoloid;oblong;broadly or narrowly turbinate +
0.3 cm3 mm <br />0.003 m <br /> (0.35 cm3.5 mm <br />0.0035 m <br />) +
2 (?) +  and 3 (?) +
septate +, hollow +  and solid +
compressed +, terete +  and trigonous +
papillate +
cleft +, 2-fid +  and undivided +
cancellate +  and smoothish +
Phaeocephalum brachychaetum +  and Rhynchospora blauneri +
Rhynchospora brachychaeta +
Rhynchospora +
species +
sulcate +  and 2-edged +
flattened +
0.03 cm0.3 mm <br />3.0e-4 m <br /> (0.05 cm0.5 mm <br />5.0e-4 m <br />) +
plant +  and cespitose +