Flora of North America species comparison

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Juncus acutiflorus

Juncus roemerianus

sharpflower rush

black needlerush, needle rush, needlegrass rush
Habit Herbs, perennial, rhizomatous, to 8 dm. Herbs, perennial, 5–15 dm.
Rhizomes

5–6 mm diam., nodes not swollen.

long, thick, scaly.
Culms

erect, terete, 3 mm diam., smooth.

gray-green, 2–5 mm diam.
Cataphylls

1, straw-colored, apex acute.

2–5.
Leaves

basal 1, cauline 2;

auricles 0.5 mm, apex rounded, cartilaginous;

blade 7–45 cm x 1–2 mm, terete, not scabrous.

basal, 1–3;

auricles absent;

blade terete, 40–80 cdm × 1.5–2.5 mm.
Inflorescences

terminal panicles of 70–120 heads, 6–10 cm, branches ascending;

primary bract erect;

heads 3–5(–8)-flowered, obconic, 2–4 mm diam.

sympodial or appearing lateral, glomerules to 150, each with 2–6 perfect or pistillate flowers, congested to open, 4–20 × 5–10 cm;

primary bracts terete, longer than inflorescence.
Flowers

tepals dark reddish brown, lanceolate, apex acuminate to subulate tipte;

outer tepals 1.9–2.2 mm;

inner tepals 2–2.3 mm;

stamens 6, anthers 2 times filament length.

tepals pale brown, 2.5–3.3 mm, apex acuminate;

outer series acuminate;

inner series slightly shorter, acutish;

stamens 6, sometimes rudimentary, filaments 0.2–0.7 mm, anthers 1.3–2.5 mm;

style 0.3–1 mm.
Capsules

inserted with beak exserted, straw-colored, 1-locular, narrowly ovoid, 2.3–2.4 mm, tapering to subulate tip, valves separating at dehiscence.

brown, 3-locular, ovoid to oblate, 1.7–3 × 1.3–1.6 mm, mostly distinctly shorter than perianth, apiculate.
Seeds

narrowly ovoid, 0.5–0.6 mm, not tailed;

body clear yellow-brown.

dark brown, ellipsoid, 0.4–0.6 mm, not tailed.

Juncus acutiflorus

Juncus roemerianus
Phenology Fruiting fall. Flowering and fruiting spring–early fall.
Habitat Wet woods Coastal tidal marshes in dense zonal stands
Elevation 0–10 m (0–0 ft)
Distribution
from FNA
NF; SPM; Europe; Asia; Africa
[BONAP county map]
from FNA
AL; DC; DE; FL; GA; LA; MD; MS; NC; SC; VA; Texas
[WildflowerSearch map]
[BONAP county map]
Source FNA vol. 22. FNA vol. 22.
Parent taxa Juncaceae > Juncus > subg. Septati Juncaceae > Juncus > subg. Juncus
Sibling taxa
J. acuminatus, 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. 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. 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
Name authority Ehrhart: in G. F. Hoffmann, Deutschl. Fl. 1: 125. (1791) Scheele: Linnaea 22:348. (1849)
Web links 
Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).



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