FNA: Juncus acutiflorus vs. Juncus acuminatus

	Juncus acutiflorus	Juncus acuminatus
	sharpflower rush	knotty-leaf rush, sharp-fruit rush, tapered rush, tapertip rush
Habit	Herbs, perennial, rhizomatous, to 8 dm.	Herbs, perennial, cespitose, not rhizomatous, 1.4–10 dm.
Rhizomes	5–6 mm diam., nodes not swollen.
Culms	erect, terete, 3 mm diam., smooth.	erect, terete, 1–3 mm diam., smooth.
Cataphylls	1, straw-colored, apex acute.	1–2, gray, apex acute.
Leaves	basal 1, cauline 2; auricles 0.5 mm, apex rounded, cartilaginous; blade 7–45 cm x 1–2 mm, terete, not scabrous.	basal 1–2, cauline 1–2; auricles 1–1.5 mm, apex rounded, scarious; blade green, straw-colored, or pink, nearly terete, 1–40 cm.
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.	terminal panicles of 5–50 heads, 5–15 cm, branches ascending; primary bract erect; heads (2–)5–20(–50)-flowered, hemispheric (to spheric), 3–10 mm diam.
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 light brown to greenish, lanceolate, 2.6–3.5(–3.9) mm, apex acuminate; stamens 3 (or 6), anthers 1/3 filament length.
Capsules	inserted with beak exserted, straw-colored, 1-locular, narrowly ovoid, 2.3–2.4 mm, tapering to subulate tip, valves separating at dehiscence.	equaling perianth or slightly exserted, straw-colored, 1-locular, ellipsoid to narrowly ovoid, 2.8–3.5(–4) mm, apex acute, valves separating at dehiscence, fertile throughout or only proximal to middle.
Seeds	narrowly ovoid, 0.5–0.6 mm, not tailed; body clear yellow-brown.	ellipsoid to oblong, 0.3–0.4 mm, not tailed; body clear yellow-brown.
2n		= 40.

	Juncus acutiflorus	Juncus acuminatus
Phenology	Fruiting fall.	Fruiting early summer–fall.
Habitat	Wet woods	Shores, swamps, ditches, springs, wet meadows, and rock outcrops
Elevation	0–10 m (0–0 ft)	0–2200 m (0–7200 ft)
Distribution	NF; SPM; Europe; Asia; Africa [BONAP county map]	AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; NE; NH; NJ; NM; NY; OH; OK; OR; PA; RI; SC; TN; TX; VA; VT; WA; WI; WV; BC; NS; ON; QC; Mexico; Central America (Honduras) [WildflowerSearch map] [BONAP county map]
Source	FNA vol. 22.	FNA vol. 22.
Parent taxa	Juncaceae > Juncus > subg. Septati	Juncaceae > Juncus > subg. Septati
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. 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. triglumis, J. trigonocarpus, J. uncialis, J. validus, J. vaseyi, J. xiphioides
Synonyms		J. acuminatus var. legitimus, J. pallescens, J. pondii
Name authority	Ehrhart: in G. F. Hoffmann, Deutschl. Fl. 1: 125. (1791)	Michaux: Flora Boreali-Americana 1: 192. (1803)
Web links	WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, Go Botany, IL Wildflowers, KS Wildflowers, LA Plants, MD Biodiversity, MI Flora, MN Wildflowers, MO Plants, PNW Herbaria WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Juncus acuminatus

sharpflower rush

knotty-leaf rush, sharp-fruit rush, tapered rush, tapertip rush

Habit

Herbs, perennial, rhizomatous, to 8 dm.

Herbs, perennial, cespitose, not rhizomatous, 1.4–10 dm.

Rhizomes

5–6 mm diam., nodes not swollen.

Culms

erect, terete, 3 mm diam., smooth.

erect, terete, 1–3 mm diam., smooth.

Cataphylls

1, straw-colored, apex acute.

1–2, gray, apex acute.

Leaves

basal 1, cauline 2;

auricles 0.5 mm, apex rounded, cartilaginous;

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

basal 1–2, cauline 1–2;

auricles 1–1.5 mm, apex rounded, scarious;

blade green, straw-colored, or pink, nearly terete, 1–40 cm.

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.

terminal panicles of 5–50 heads, 5–15 cm, branches ascending;

primary bract erect;

heads (2–)5–20(–50)-flowered, hemispheric (to spheric), 3–10 mm diam.

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 light brown to greenish, lanceolate, 2.6–3.5(–3.9) mm, apex acuminate;

stamens 3 (or 6), anthers 1/3 filament length.

Capsules

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

equaling perianth or slightly exserted, straw-colored, 1-locular, ellipsoid to narrowly ovoid, 2.8–3.5(–4) mm, apex acute, valves separating at dehiscence, fertile throughout or only proximal to middle.

Seeds

narrowly ovoid, 0.5–0.6 mm, not tailed;

body clear yellow-brown.

ellipsoid to oblong, 0.3–0.4 mm, not tailed;

body clear yellow-brown.

= 40.

Juncus acutiflorus

Juncus acuminatus

Phenology

Fruiting fall.

Fruiting early summer–fall.

Habitat

Wet woods

Shores, swamps, ditches, springs, wet meadows, and rock outcrops

Elevation

0–10 m (0–0 ft)

0–2200 m (0–7200 ft)

Distribution

NF; SPM; Europe; Asia; Africa

[BONAP county map]

AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; NE; NH; NJ; NM; NY; OH; OK; OR; PA; RI; SC; TN; TX; VA; VT; WA; WI; WV; BC; NS; ON; QC; Mexico; Central America (Honduras)

[WildflowerSearch map]

[BONAP county map]

Source

FNA vol. 22.

Parent taxa

Juncaceae > Juncus > subg. Septati

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. 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. triglumis, J. trigonocarpus, J. uncialis, J. validus, J. vaseyi, J. xiphioides

Synonyms

J. acuminatus var. legitimus, J. pallescens, J. pondii

Name authority

Ehrhart: in G. F. Hoffmann, Deutschl. Fl. 1: 125. (1791)

Michaux: Flora Boreali-Americana 1: 192. (1803)

Web links

Local floras: BC, CA, OR, WA
Local Web sites: CalFlora, CalPhotos, Flora NW, Go Botany, IL Wildflowers, KS Wildflowers, LA Plants, MD Biodiversity, MI Flora, MN Wildflowers, MO Plants, PNW Herbaria
WildflowerSearch
iNaturalist (observations)
USDA Plants Database
LBJ Wildflower Center
SEINet
Plants of the World Online
Encyclopedia of Life
Wikipedia
Google Image Search

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).

Choose a data source: Flora of North America, OregonFlora, UW Burke Herbarium

The species comparison tool is brought to you by:

Flora of North America species comparison

Juncus acutiflorus

Juncus acuminatus

Juncus acutiflorus

Juncus acuminatus