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anglestem beaksedge

starrush whitetop, white star sedge

Habit Plants perennial, cespitose, 70–150 cm; rhizomes often present, short, scaly. Plants perennial, cespitose or solitary, to 70 cm; rhizomes slender, scaly, to 2 mm thick.
Culms

erect or ascending, leafy, trigonous.

erect, slender, leafy-based, trigonous, several-ribbed.

Leaves

exceeded by culm;

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

spreading to erect, overtopped by culm;

blades narrowly linear, proximally flattened, 0.5–3 mm wide, apex tapering, trigonous.

Inflorescences

terminal and axillary;

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

terminal, solitary, headlike, dense, white, leafy-involucrate;

involucral bracts several, flaring to recurved, white from broadened base nearly to median, then green to tapered tip, longer bracts 13 cm × 2–7 mm.

Spikelets

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

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

white, ovoid, 5–7 mm, apex acute;

fertile scales many, boatshaped, sharply curvedkeeled, 3–4(–5) mm, apex acute or blunt.

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.

several per spikelet, 1.5–1.7(–2) mm;

body yellow to mahogany, broadly pyriformobovoid, tumidly lenticular, 1 × 0.5–0.7 mm, widest at apex, margins thickened, interrupted at base of tubercle;

surfaces transversely undulaterugose, ridges contiguous, of shortlinear papillae;

tubercle broadly triangular, 0.5–0.6 mm, graycrustaceous, apex short acuminate.

2n

= 12.

Rhynchospora caduca

Rhynchospora colorata

Phenology Fruiting summer–fall. Fruiting late spring–summer.
Habitat Low meadows, clearings, marshes, marsh borders, seeps, bog moats, savannas, ditches, pine flatwoods, swamps Sands, peats, and silt of interdunal swales, shores, meadowy swales, and marsh edges, sometimes fens, usually on circumneutral or basic substrates
Elevation 0–400 m (0–1300 ft) 0–300 m (0–1000 ft)
Distribution
from FNA
AL; AR; FL; GA; LA; MS; NC; OK; SC; TN; TX; VA
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; AR; FL; GA; LA; MS; NC; SC; TX; VA; Mexico; Central America; West Indies; South America (French Guiana)
[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.)

Rhynchospora colorata is a slender and clonal version of R. latifolia, with a distinct preference for more basic substrates; involucral bracts are very slender and have a longer portion of green, usually reaching well proximal to midbract.

See also 16. Rhynchospora latifolia.

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

Source FNA vol. 23, p. 223. FNA vol. 23, p. 215.
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. 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 caducum, R. patula Schoenus coloratus, Dichromena cephalotes, Dichromena colorata, Dichromena leucocephala, R. drummondiana, Scirpus cephalotes
Name authority Elliott: Sketch Bot. S. Carolina 1: 62. (1816) (Linnaeus) H. Pfeiffer: Repert. Spec. Nov. Regni Veg. 38: 89. (1935)
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