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black needle rush, blackgrass, blackgrass rush, Gerard's rush, saltmarsh rush, saltmeadow rush

dichotomous rush, fork rush

Habit Herbs, perennial, 2–9 dm. Herbs, perennial, to 10 dm.
Rhizomes

long- creeping.

densely branched to short- creeping.

Cataphylls

1–3.

1–3.

Leaves

basal, (1–)2–4;

auricles 0.4–0.6(–0.8) mm, scarious;

blade flat or somewhat channeled, 10–40 cm × 0.4–0.7 mm, margins entire.

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

10–30(–80)-flowered, usually loose and somewhat lax, 2–16 cm;

primary bract rarely surpassing inflorescence.

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

primary bract usually exceeding inflorescence.

Flowers

bracteoles 2;

tepals dark brown or blackish, lanceolate-ovate to oblong, 2.6–3.2(–3.8) mm;

inner and outer series nearly equal, apex obtuse;

stamens 6, filaments 0.4–0.7 mm, anthers 1.1–1.6(–1.8) mm;

style 0.4 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

chestnut brown or brown, 3-locular, widely ellipsoid, (2.2–)2.5–3.2(–3.5) × 1.3–1.9 mm.

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

dark brown, ellipsoid to lunate, 0.485–0.6(–0.67) mm, not tailed.

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

2n

= ca. 80, 84.

= ca. 80.

Juncus gerardii

Juncus dichotomus

Phenology Flowering and fruiting late spring–summer. Flowering and fruiting late spring–summer.
Habitat Forming extensive colonies in exposed coastal estuary meadows and salt marshes just above high- tide line, also inland Ditches, shores, clearings, and other typically open areas, usually in sandy, well-drained (but frequently wet) soil
Distribution
from FNA
CO; CT; DE; IL; IN; KS; KY; MA; MD; ME; MI; MN; MO; MT; ND; NH; NJ; NY; OH; OR; OR; PA; RI; UT; VA; VT; WA; WI; BC; MB; NB; NF; NS; ON; PE; QC; SPM; Greenland; Europe; Asia
[WildflowerSearch 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]
Source FNA vol. 22. FNA vol. 22.
Parent taxa Juncaceae > Juncus > subg. Poiophylli 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. 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. bulbosus var. gerardii, J. fucensis, J. gerardii var. pedicellatus J. dichotomus var. platyphyllus, J. tenuis var. dichotomus, J. tenuis var. platyphyllus, J. platyphyllus
Name authority Loiseleur-Deslongchamps: J. Bot. (Desvaux) 2: 284. (1809) Elliott
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