Carex sect. Vulpinae
Bull. Soc. Roy. Bot. Belgique 24: 18. 1886.
Plants cespitose, short-rhizomatous. Culms dark brown to black at base, usually more than 1 mm wide. Leaves: basal sheaths fibrous or not; sheath fronts sometimes dotted brown, yellow, or red, at least a narrow hyaline or whitish hyaline band on distal leaves, membranous, transversely rugose or smooth; blades V-shaped in cross section when young, glabrous. Inflorescences racemose or paniculate, often condensed, with 4–20+ spikes; proximal bracts filiform or scalelike, sheathless; lateral spikes androgynous or pistillate, sessile, prophyllate; terminal spike androgynous. Proximal pistillate scales with apex obtuse to acuminate or short-awned. Perigynia ascending to spreading, veined abaxially, veined or veinless adaxially, stipitate, lanceolate to ovate, plano-convex in cross section, mostly 2 times as long as wide, widest at base, base rounded or truncate, with spongy tissue, margins acutely angled, apex tapering or abruptly contracted to beak, glabrous; beak with apex bidentate or subentire, with abaxial suture. Stigmas 2. Achenes biconvex, smaller than bodies of perigynia; style deciduous.
North America, temperate Eurasia, n, e, s Africa, s Australia.
Species ca. 15 (9 in the flora).
Carex sect. Vulpinae is not clearly distinguished from several other sections, especially sect. Multiflorae. Features that generally distinguish sect. Vulpinae from sect. Multiflorae include the presence of spongy tissue in the perigynium bases, the perigynia tapered to a beak, and the cylindric persistent style bases, but there are taxa within each section possessing different combinations of these characters. Within sect. Vulpinae morphologic similarity distinguishes several groups of species. Many eastern taxa and the widely distributed Carex stipata have elongated inflorescences, hyaline scales, perigynium bases distended by spongy tissue, and at least one conspicuous setaceous bract (although C. alopecoidea and C. conjuncta lack distended perigynium bases). The western taxa have very condensed inflorescences with brown scales, perigynia that are not basally distended, and scalelike bracts. Among the western species, C. neurophora and C. nervina are morphologically very similar, appear to have a recent common origin, and are strongly differentiated from C. jonesii by vegetative morphology.
|1||Inflorescences very condensed, globose to ovoid or shortly cylindric; proximal branches not distinguishable and proximal internode not visible, to 3 mm; bracts scalelike, not visible.||> 2|
|1||Inflorescences elongated, cylindric; proximal branches distinguishable and proximal internode usually visible, usually more than 3 mm; at least proximal bracts setaceous, apparent.||> 4|
|2||Leaves clustered at base; proximal sheaths with long blades, fronts hyaline; perigynium beak smooth.||Carex jonesii|
|2||Leaves not clustered at base; proximal sheaths with short blades, fronts herbaceous; perigynium beak smooth or scabrous.||> 3|
|3||Distal sheath fronts smooth, apex coriaceous, concave; perigynium beak smooth.||Carex nervina|
|3||Distal sheath fronts rugose, apex hyaline, convex; perigynium beak scabrous.||Carex neurophora|
|4||Apex of sheath front yellow, thickened, not fragile; leaf blades papillose adaxially (25X).||Carex laevivaginata|
|4||Apex of sheath front not yellow, thin, usually fragile; leaf blades not papillose.||> 5|
|5||Larger perigynia 6–8 mm, prominently distended at base and forming basal disk; sheath fronts smooth, red dotted.||Carex crus-corvi|
|5||Perigynia less than 6 mm, prominent basal disk absent, sometimes somewhat distended at base; sheath fronts smooth or rugose, dotted or not.||> 6|
|6||Perigynia veinless adaxially, not distended at base.||> 7|
|6||Perigynia veined adaxially, distended at base.||> 8|
|7||Sheath fronts smooth; achenes circular; perigynia with 3–5 faint veins abaxially or veinless.||Carex alopecoidea|
|7||Sheath fronts rugose; achenes ovate; perigynia with 3–5 prominent veins abaxially.||Carex conjuncta|
|8||Sheath fronts smooth, with tubular extension above blade junction; ligules to 4 mm; culms not easily compressed, proximal sheaths bladeless.||Carex oklahomensis|
|8||Sheath fronts rugose, not forming tubular extension above blade junction; ligules to 10 mm; culms easily compressed, proximal sheaths usually with blades.||Carex stipata|