Rhynchospora harperi
Rhynchospora thornei
Harper's beaksedge
Thorne's beaksedge
erect to excurved, leafybased, narrowly linear, ± terete.
lax, filiform, leafy.
shorter than culm;
blades ascending, narrowly linear, proximally flat or margins slightly involute, 0.5–1(–2) mm wide, distally canaliculate, apex trigonous, tapering, subulate.
spreading to ascending, exceeding or exceeded by culm;
blades 0.2–0.3 mm wide, margins strongly involute or channeled, apex trigonous, tapering, setaceous.
spikelet clusters 1–3, laterals 0–2, all turbinate to hemispheric, terminal internode usually excurved; leafy bracts setaceous, overtopping inflorescence.
cluster of cymes 1–2, widely spaced, turbinate, sparse;
branches few; foliaceous bracts setaceous, longer than cymes.
redbrown, lanceoloid, 5–7 mm, apex acute;
fertile scales lanceolate, (2.5–)4–5 mm, apex acute to acuminate;
midrib paralleled by several indistinct ribs, excurrent as short awns.
brown, lanceovoid to fusiform, 2.5–3 mm, apex acuminate;
fertile scales ovate, 1.5 mm, apex acute, midrib shortexcurrent.
bristles 6, reaching from mid tubercle to beyond tip.
perianth absent.
3(–4) per spikelet, 2.1–2.5 mm;
stipe and receptacle 0.2–0.3 mm, sparsely setose and setulose;
body glossy, brown with pale center, obovoid-lenticular, 1.1–1.5 × 1–1.1 mm, surfaces finely longitudinally lined, variably low papillatecancellate, also often transversely with wavy lines of dark dots;
tubercle flattened, triangular-subulate, (0.8–)0.9–1(–1.1) mm, setulose-ciliate.
0.9–1 mm;
body lustrous pale brown, ellipsoidlenticular, 0.8–0.9 × 0.5–0.6 mm, margins narrow, wirelike;
surfaces minutely reticulate;
bristles 4–6, the longest from shorter than fruit midbody to fully as long, rarely reaching tubercle tip, minutely antrorsely barbellate;
tubercle shortconic, to 0.15 mm.
Rhynchospora harperi
Rhynchospora thornei
Rhynchospora harperi is most abundant in a very special habitat referred to here as the “Hypericum pond.” These are typically shallow ponds in pine savannas, frequently ringed by stands of Nyssa, Taxodium, Ilex, and Cyrilla, but most of the pond itself is dominated by one or more myriandrous shrubby Hypericum species. Here R. harperi is distinguished from other species by the often abrupt bend of its ultimate internode.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Of conservation concern.
Rhynchospora thornei, discovered by Robert Thorne from margins of a limesink pond in southwestern Georgia, has been extirpated at that site. Now the taxon is known from several Alabama and Florida locations and was recently found in eastern North Carolina by R. J. LeBlond.
Had S. Gale been sent material of Rhynchospora thornei at the time she was doing her excellent revision, she probably would have treated it as part of her series Rariflorae. Yet without its perianth bristles, R. thornei would be nearly identical to R. divergens and very similar to R. pusilla, both of which belong in subg. Psilocarya. Therefore, it forms an interesting link between subg. Rhynchospora (Eurhynchospora sensu Gale) and subg. Psilocarya.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
MD Biodiversity
WildflowerSearch
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USDA Plants Database
