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weak rush

dichotomous rush, fork rush

Habit Herbs, perennial, cespitose, 1–2.5 dm. Herbs, perennial, to 10 dm.
Rhizomes

densely branched to short- creeping.

Culms

erect, terete, 1–2 mm diam., smooth.

Cataphylls

0–1, maroon or dark green, apex acute.

1–3.

Leaves

basal 0–1, cauline 1–3;

auricles 1–1.5 mm, apex rounded, scarious;

blade maroon or dark green, terete, 1–12.5 cm × 0.5–1.5 mm.

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

terminal panicles of 3–50 heads, 2–8 cm, branches ascending to spreading;

primary bract erect;

heads 2–10-flowered, obpyramidal, 2–5 mm diam.

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

primary bract usually exceeding inflorescence.

Flowers

tepals green to straw-colored, lanceolate, 1.8–2.3(–2.5) mm, apex sharply acuminate;

stamens 3, 1/2 filament length.

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

exserted, straw-colored, 1-locular, narrowly ellipsoid to lanceoloid, 2.8–3.7 7(–4.2) mm, apex acute, valves separating at dehiscence.

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

ellipsoid, 0.3–0.4 mm, not tailed;

body clear yellow-brown.

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

2n

= ca. 80.

Juncus debilis

Juncus dichotomus

Phenology Fruiting summer. Flowering and fruiting late spring–summer.
Habitat Marshy shores, in small streams, swamps, wet clearings, spring runs, commonly in very soft mucky substrates Ditches, shores, clearings, and other typically open areas, usually in sandy, well-drained (but frequently wet) soil
Elevation 0–700 m (0–2300 ft)
Distribution
from FNA
AL; AR; DE; FL; GA; IL; KY; LA; MD; MO; MS; NC; NJ; NY; PA; SC; TN; TX; VA; Mexicos (Chiapas); Central America (Honduras)
[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

Juncus debilis A. Gray is a name being proposed for conservation.

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

Source FNA vol. 22. FNA vol. 22.
Parent taxa Juncaceae > Juncus > subg. Septati 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. 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. 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. 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
Synonyms J. acuminatus var. debilis, J. radicans J. dichotomus var. platyphyllus, J. tenuis var. dichotomus, J. tenuis var. platyphyllus, J. platyphyllus
Name authority A. Gray: Manual 481506. (1848) Elliott
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