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three-flower rush, three-hulled rush

dichotomous rush, fork rush

Habit Herbs, perennial, cespitose, 0.3–3.5 dm. Herbs, perennial, to 10 dm.
Rhizomes

densely branched to short- creeping.

Culms

1–8, 0.3–0.5 mm diam.

Cataphylls

1–2.

1–3.

Leaves

basal, 2–4;

auricles slightly prolonged, rounded, scarious to ± leathery;

blade deeply channeled, 2–10 cm, mostly shorter than culms.

basal, (1-)2-3;

auricles 0.2-0.5(-0.6) mm, scarious to leathery;

blade nearly terete, channeled or flat, 10-25(-40) cm × (0.5-)0.7-1(-1.2) mm, margins entire.

Inflorescences

solitary heads, each with 2–3(–50) flowers;

primary bracts brownish, nearly equal to or slightly shorter thanabout equaling inflorescence.

terminal, (5–)10–85(–100)-flowered, congested to somewhat loose, (1-)2.5-10(-13) cm;

primary bract usually exceeding inflorescence.

Flowers

tepals pale brown or darker, oblong-lanceolate, 3–5 mm, outer and inner series nearly equal;

stamens 6, filaments 2.5–4 mm, anthers 0.6–1 mm;

styles 0.5–0.8 mm.

bracteoles 2;

tepals green, lanceolate, (3-)3.3-4.5(-5.5) mm;

outer and inner series nearly equal;

stamens 6, filaments 0.6–1.2 mm, anthers 0.4-0.8(-1) mm;

style 0.2 mm.

Capsules

tan, pseudo-3-locular, 3-gonous–cylindric, apex obtuse, mucronate.

tan to brown, 1-locular to pseudo-3-locular, ellipsoid to widely so, (2.5-)2.8-3.5(-4.5) × 1x 1.6-2.2 mm.

Seeds

tan or darker, fusiform, body 0.5–1 mm, tails 0.6–1 mm.

brownish to amber, ellipsoid to lunate, 0.3-0.4 mm, not tailed.

2n

= ca. 80.

Juncus triglumis

Juncus dichotomus

Phenology Flowering and fruiting late spring–summer.
Habitat Ditches, shores, clearings, and other typically open areas, usually in sandy, well-drained (but frequently wet) soil
Distribution
from FNA
AK; CO; ID; MT; NM; OR; UT; WY; AB; BC; MB; NT; NU; ON; QC; SK; YT; Eurasia
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; AR; CO; CT; DC; DE; FL; GA; KY; LA; MA; MD; MS; NC; NJ; NY; OH; PA; RI; SC; TN; VA; WV; Mexico; Central America; South America; Texas
[WildflowerSearch map]
[BONAP county map]
Discussion

Varieties 3 (2 in the flora).

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

Key
1. Most proximal bracts of inflorescence obtuse to mucronate, usually much shorter than inflorescence; capsules well exserted from perianth, 4.5–7 mm, apex conic or rounded proximal to persistent style
var. triglumis
1. Most proximal bracts of infloresecence equal to or longer than inflorescence, apex long acuminate or awned; capsules included or barely exserted from perianth, 3–5 mm, apex nearly truncate proximal to persistent style
var. albescens
Source FNA vol. 22. FNA vol. 22.
Parent taxa Juncaceae > Juncus > subg. Alpini 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. polycephalus, 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. 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. 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. 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
Subordinate taxa
J. triglumis var. albescens, J. triglumis var. triglumis
Synonyms J. dichotomus var. platyphyllus, J. tenuis var. dichotomus, J. tenuis var. platyphyllus, J. platyphyllus
Name authority Linnaeus: Sp. Pl. 1: 328. (1753) Elliott
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