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anglestem beaksedge

Curtiss' beaksedge

Habit Plants perennial, cespitose, 70–150 cm; rhizomes often present, short, scaly. Plants perennial, densely cespitose, 10–30 cm; rhizomes absent.
Culms

erect or ascending, leafy, trigonous.

lax, erect to excurved, leafy toward base, filiform.

Leaves

exceeded by culm;

blades linear, proximally 4–7 mm wide, apex trigonous, tapering.

overtopped by scape;

blades filiform, distally flattened, channeled, tapering, to 1 mm wide, margins strongly involute, apex blunt.

Inflorescences

terminal and axillary;

clusters 3–6, mostly dense, narrowly to broadly turbinate, branches ascending; leafy bracts exceeeding proximalmost inflorescences.

spikelet clusters 1–3, laterals widely spaced, all narrowly turbinate, ellipsoid, or ovoid; leafy bracts setaceous, overtopping proximal clusters, often overtopped by terminal ones.

Spikelets

rich brown, ovoid, (3–)4–5 mm, apex acuminate;

fertile scales ovate, 2.5–3.5 mm, apex acuminate, midrib included or shortexcurrent.

erect or ascending, redbrown, lanciform, mostly 4.5–5 mm, apex acute;

fertile scales lanceolate, (3–)4–4.5 mm, apex acute, apiculate.

Flowers

perianth bristles mostly 6, exceeding tubercle tip.

perianth absent.

Fruits

mostly 3–4 per spikelet, 2–2.2 mm;

body brown on short pedicellar (to 0.3 mm) stalk, broadly obovoid, lenticular, 1.3–1.5 × 1–1.5 mm, surfaces transversely rugulose, vertically finely striate and rectangularalveolate;

tubercle compressed, triangular acuminate, 0.5–0.8 mm, edges setulose.

2–3(–5) per spikelet;

stipe and receptacle 0.1–0.2(–0.3) mm, setose;

body brown with pale glassy center, narrowly obovoidellipsoid, lenticular, 1.2–1.5 mm, margins narrow, flowing to tubercle;

surfaces very finely lined longitudinally, transversely with wavy lines of tiny pits;

tubercle narrowly triangular or slightly concavesided, flattened, 0.7–1.2(–1.5) mm.

Rhynchospora caduca

Rhynchospora curtissii

Phenology Fruiting summer–fall. Fruiting summer–fall.
Habitat Low meadows, clearings, marshes, marsh borders, seeps, bog moats, savannas, ditches, pine flatwoods, swamps Sands and peats of bogs, pineland pond shores, seeps, and low moist savannas
Elevation 0–400 m (0–1300 ft) 0–100 m (0–300 ft)
Distribution
from FNA
AL; AR; FL; GA; LA; MS; NC; OK; SC; TN; TX; VA
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; FL; MS
[BONAP county map]
Discussion

Rhynchospora caduca has its closest relationships with the even more robust R. odorata Grisebach, on the one hand, and the swampinhabiting, more slender, and rhizomatous R. mixta Britton ex Small, on the other. Intergrades with R. odorata appear in Alabama and northwest Florida; intergrades with R. mixta appear where ranges overlap in both the Atlantic and Gulf coastal plains.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 23, p. 223. FNA vol. 23, p. 234.
Parent taxa Cyperaceae > Rhynchospora Cyperaceae > Rhynchospora
Sibling taxa
R. alba, R. baldwinii, R. brachychaeta, R. breviseta, R. californica, R. capillacea, R. capitellata, R. careyana, R. cephalantha, R. chalarocephala, R. chapmanii, R. ciliaris, R. colorata, R. compressa, R. corniculata, R. crinipes, R. curtissii, R. debilis, R. decurrens, R. divergens, R. elliottii, R. eximia, R. fascicularis, R. fernaldii, R. filifolia, R. floridensis, R. fusca, R. globularis, R. glomerata, R. gracilenta, R. grayi, R. harperi, R. harveyi, R. indianolensis, R. inexpansa, R. inundata, R. knieskernii, R. kunthii, R. latifolia, R. macra, R. macrostachya, R. megalocarpa, R. megaplumosa, R. microcarpa, R. microcephala, R. miliacea, R. mixta, R. nitens, R. nivea, R. odorata, R. oligantha, R. pallida, R. perplexa, R. pineticola, R. pleiantha, R. plumosa, R. punctata, R. pusilla, R. rariflora, R. recognita, R. scirpoides, R. solitaria, R. stenophylla, R. thornei, R. torreyana, R. tracyi, R. wrightiana
R. alba, R. baldwinii, R. brachychaeta, R. breviseta, R. caduca, R. californica, R. capillacea, R. capitellata, R. careyana, R. cephalantha, R. chalarocephala, R. chapmanii, R. ciliaris, R. colorata, R. compressa, R. corniculata, R. crinipes, R. debilis, R. decurrens, R. divergens, R. elliottii, R. eximia, R. fascicularis, R. fernaldii, R. filifolia, R. floridensis, R. fusca, R. globularis, R. glomerata, R. gracilenta, R. grayi, R. harperi, R. harveyi, R. indianolensis, R. inexpansa, R. inundata, R. knieskernii, R. kunthii, R. latifolia, R. macra, R. macrostachya, R. megalocarpa, R. megaplumosa, R. microcarpa, R. microcephala, R. miliacea, R. mixta, R. nitens, R. nivea, R. odorata, R. oligantha, R. pallida, R. perplexa, R. pineticola, R. pleiantha, R. plumosa, R. punctata, R. pusilla, R. rariflora, R. recognita, R. scirpoides, R. solitaria, R. stenophylla, R. thornei, R. torreyana, R. tracyi, R. wrightiana
Synonyms Phaeocephalum caducum, R. patula Phaeocephalum curtissii, R. filifolia var. ellipsoidea
Name authority Elliott: Sketch Bot. S. Carolina 1: 62. (1816) Britton: in J. K. Small, Fl. S.E. U.S., 195, 1327. (1903)
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