Rhynchospora chalarocephala

Fernald & Gale

Rhodora 42: 426, figs. 1, 2. 1940.

Treatment appears in FNA Volume 23. Treatment on page 212. Mentioned on page 202.
Revision as of 21:07, 16 December 2019 by FNA>Volume Importer
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Plants perennial, cespitose, 30–100 cm; rhizomes absent. Culms erect to ascending-arching, slender, nearly terete, multiribbed. Principal leaves exceeded by culm; blades flat, linear, 1–2 mm wide, apex tapering, trigonous. Inflorescences: spikelet clusters 3–7, widely spaced, clusters loosely turbinate to hemispheric, to 1.3 cm wide. Spikelets brown to pale red-brown, lance-fusiform, 3–5.5 mm; fertile scales elliptic, 2.5–4 mm, acute, midrib short-excurrent. Flowers: perianth bristles 6, ± equaling tubercle. Fruits 1 per spikelet, (2.5–)2.7–3.3(–3.5) mm, body pale brown with yellowish center, ± broadly oblong-obovoid distal to stipe, lenticular, 1.5–2 × 0.8–1 mm; tubercle narrowly triangularsubulate, (1–)1.2–1.5(–2) mm, less than 0.5 mm wide at base.


Phenology: Fruiting summer–fall.
Habitat: Moist sands and sandy peats of savannas, acidic stream banks, seeps, flatwoods, ditches, and pond shores
Elevation: 0–400 m

Distribution

V23 364-distribution-map.jpg

Ala., Del., D.C., Fla., Ga., La., Md., Miss., N.J., N.C., Okla., S.C., Tenn., Tex., Va.

Discussion

Some specimens of Rhynchospora chalarocephala are very difficult to distinguish from R. microcephala, and unquestionably intergrades occur in peninsular Florida and the Gulf southern coastal plain. Rhynchospora chalarocephala tends to have longer, paler, narrower spikelets in looser clusters; the dilated part of the fruit body has a narrower, more oblong outline; and the tubercle is both narrower with a narrower base and longer (mostly 1–1.5 mm versus 0.9–1.2 mm in R. micro-cephala). Most material is easily sorted because R. chalarocephala has paler spikelets in turbinate to hemispheric clusters; the dark brown spikelets of R. microcephala are in globose heads.

Selected References

None.

Lower Taxa

None.
Robert Kral +
Fernald & Gale +
Ala. +, Del. +, D.C. +, Fla. +, Ga. +, La. +, Md. +, Miss. +, N.J. +, N.C. +, Okla. +, S.C. +, Tenn. +, Tex. +  and Va. +
0–400 m +
Moist sands and sandy peats of savannas, acidic stream banks, seeps, flatwoods, ditches, and pond shores +
Fruiting summer–fall. +
Dichromena +  and Psilocarya +
Rhynchospora chalarocephala +
Rhynchospora +
species +