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flatleaf rush, manyhead rush

heath rush, mosquito rush, mosquito rush (vascan)

Habit Herbs, perennial, cespitose, 6–10 dm. Herbs, perennial, cespitose to mat-forming, 2–5 dm.
Rhizomes

short, nearly erect, branching.

Culms

erect, 3–14 mm diam.

1(–2).

Cataphylls

absent.

2–4.

Leaves

basal 2–3(–6), cauline 1–4, brownish green;

auricles absent;

blade 8–70 cm × 4–8 mm.

basal, 3–6;

auricles 0.2–0.4 mm, membranous to scarious;

blade arcuate, spreading, grayish green, channeled, 7–30 cm × 1–2 mm, nearly leathery, margins entire.

Inflorescences

panicles of 16–82 heads, 10–30 cm;

primary bract erect;

heads 20–30-flowered, spheric, 8–12 mm diam.

terminal, 7–40-flowered, somewhat loose, 3–10 × 1–2 cm;

primary bract usually shorter than inflorescence.

Flowers

tepals green to reddish, lance-subulate, 3–4 mm, nearly equal, apex acuminate;

stamens 3, anthers 1/3–1/2 length of filaments.

pedicels 0.5–2 mm;

bracteoles 2;

tepals brown to blackish, 4–5.5 mm;

outer and inner series nearly equal, apex obtuse to nearly acute;

stamens 6, filaments 0.5 mm, anthers 1.5–2 mm;

style 0.2 mm.

Capsules

exserted, straw-colored, 1-locular, narrowly ovoid, 4–5 mm, apex tapering to beak, remaining after dehiscence.

brownish, 3-locular, ovoid to ellipsoid, 4–5 × 2.3–3 mm, nearly equal to perianth.

Seeds

lance-ellipsoid, 0.5–0.6 mm, not tailed.

brownish, ellipsoid, 0.6–0.9 mm, not tailed.

2n

= 42.

Juncus polycephalus

Juncus squarrosus

Phenology Fruiting spring–fall. Flowering and fruiting late spring–summer.
Habitat Wet or seasonally wet shores, depressions, occasionally in fairly deep water of streams, usually with a peaty or mucky substrate, occasionally sandy to gravelly Moist, open sites and bogs, occasionally disturbed areas
Elevation 0–100 m (0–300 ft) 20–200 m (100–700 ft)
Distribution
from FNA
AL; FL; GA; LA; MD; MS; NC; SC; TX
[WildflowerSearch map]
from FNA
WI; Greenland; native; Europe [Introduced in North America]
[BONAP county map]
Source FNA vol. 22. FNA vol. 22.
Parent taxa Juncaceae > Juncus > subg. Ensifolii Juncaceae > Juncus > subg. Poiophylli
Sibling taxa
J. acuminatus, J. acutiflorus, J. acutus, J. alpinoarticulatus, J. anthelatus, J. arcticus, J. articulatus, J. biglumis, J. bolanderi, J. brachycarpus, J. brachycephalus, J. brachyphyllus, J. brevicaudatus, J. bryoides, J. bufonius, J. bulbosus, J. caesariensis, J. canadensis, J. capillaris, J. capitatus, J. castaneus, J. chlorocephalus, J. compressus, J. confusus, J. cooperi, J. coriaceus, J. covillei, J. debilis, J. dichotomus, J. diffusissimus, J. drummondii, J. dubius, J. dudleyi, J. effusus, J. elliottii, J. ensifolius, J. falcatus, J. filiformis, J. filipendulus, J. georgianus, J. gerardii, J. greenei, J. gymnocarpus, J. hallii, J. hemiendytus, J. howellii, J. inflexus, J. interior, J. kelloggii, J. leiospermus, J. lesueurii, J. longistylis, J. luciensis, J. macrandrus, J. macrophyllus, J. marginatus, J. maritimus, J. megacephalus, J. mertensianus, J. militaris, J. nevadensis, J. nodatus, J. nodosus, J. occidentalis, J. orthophyllus, J. oxymeris, J. parryi, J. patens, J. pelocarpus, J. pervetus, J. phaeocephalus, J. regelii, J. repens, J. roemerianus, J. scirpoides, J. secundus, J. squarrosus, J. stygius, J. subcaudatus, J. subtilis, J. supiniformis, J. tenuis, J. texanus, J. textilis, J. tiehmii, J. torreyi, J. trifidus, J. triformis, J. triglumis, J. trigonocarpus, J. uncialis, J. validus, J. vaseyi, J. xiphioides
J. acuminatus, J. acutiflorus, J. acutus, J. alpinoarticulatus, J. anthelatus, J. arcticus, J. articulatus, J. biglumis, J. bolanderi, J. brachycarpus, J. brachycephalus, J. brachyphyllus, J. brevicaudatus, J. bryoides, J. bufonius, J. bulbosus, J. caesariensis, J. canadensis, J. capillaris, J. capitatus, J. castaneus, J. chlorocephalus, J. compressus, J. confusus, J. cooperi, J. coriaceus, J. covillei, J. debilis, J. dichotomus, J. diffusissimus, J. drummondii, J. dubius, J. dudleyi, J. effusus, J. elliottii, J. ensifolius, J. falcatus, J. filiformis, J. filipendulus, J. georgianus, J. gerardii, J. greenei, J. gymnocarpus, J. hallii, J. hemiendytus, J. howellii, J. inflexus, J. interior, J. kelloggii, J. leiospermus, J. lesueurii, J. longistylis, J. luciensis, J. macrandrus, J. macrophyllus, J. marginatus, J. maritimus, J. megacephalus, J. mertensianus, J. militaris, J. nevadensis, J. nodatus, J. nodosus, J. occidentalis, J. orthophyllus, J. oxymeris, J. parryi, J. patens, J. pelocarpus, J. pervetus, J. phaeocephalus, J. polycephalus, J. regelii, J. repens, J. roemerianus, J. scirpoides, J. secundus, J. stygius, J. subcaudatus, J. subtilis, J. supiniformis, J. tenuis, J. texanus, J. textilis, J. tiehmii, J. torreyi, J. trifidus, J. triformis, J. triglumis, J. trigonocarpus, J. uncialis, J. validus, J. vaseyi, J. xiphioides
Synonyms J. echinatus, J. engelmannii
Name authority Michaux: Flora Boreali-Americana 1: 192. 1803 (as polycephalos) Linnaeus: Sp. Pl. 1: 327. (1753)
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