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Curtiss' beaksedge

anglestem beaksedge

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

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

erect or ascending, leafy, trigonous.

Leaves

overtopped by scape;

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

exceeded by culm;

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

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.

terminal and axillary;

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

Spikelets

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

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

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

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

Flowers

perianth absent.

perianth bristles mostly 6, exceeding tubercle tip.

Fruits

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.

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.

Rhynchospora curtissii

Rhynchospora caduca

Phenology Fruiting summer–fall. Fruiting summer–fall.
Habitat Sands and peats of bogs, pineland pond shores, seeps, and low moist savannas Low meadows, clearings, marshes, marsh borders, seeps, bog moats, savannas, ditches, pine flatwoods, swamps
Elevation 0–100 m (0–300 ft) 0–400 m (0–1300 ft)
Distribution
from FNA
AL; FL; MS
[BONAP county map]
from FNA
AL; AR; FL; GA; LA; MS; NC; OK; SC; TN; TX; VA
[WildflowerSearch map]
[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. 234. FNA vol. 23, p. 223.
Parent taxa Cyperaceae > Rhynchospora Cyperaceae > Rhynchospora
Sibling taxa
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
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
Synonyms Phaeocephalum curtissii, R. filifolia var. ellipsoidea Phaeocephalum caducum, R. patula
Name authority Britton: in J. K. Small, Fl. S.E. U.S., 195, 1327. (1903) Elliott: Sketch Bot. S. Carolina 1: 62. (1816)
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