FNA: Juncus diffusissimus vs. Juncus supiniformis

	Juncus diffusissimus	Juncus supiniformis
	diffuse rush, slim-fruit rush, slim-pod rush	hair-leaf rush, hairy-leaf rush, spreading rush
Habit	Herbs, perennial, cespitose, 2.5–6.5 dm.	Herbs, perennial, cespitose or matted, often decumbent, rooting at proximal nodes or floating, 0.3–5 dm.
Culms	erect, terete, 1–3 mm diam., smooth.	erect, decumbent and rooting at nodes, or floating, terete, 1–2 mm diam., smooth.
Cataphylls	0–1, maroon or dark green, apex obtuse.	0 or 1–2, straw-colored, apex acute.
Leaves	basal 1, cauline 2–3; auricles 1–2.1 mm, apex rounded, membranaceous; blade maroon or dark green, terete to compressed, 3–20 cm × 1–2.4 mm.	basal 1–3, cauline 1–4; auricles 0.8–2.1 mm, apex rounded to acute, membranaceous; blade terete, 3.7–15 cm × 0.4–1.3 mm, occasionally with filiform, flaccid, and floating leaves to 60 cm.
Inflorescences	terminal panicles of 30–70(–130), 5–20 cm, branches spreading; primary bract erect; ; heads (1–)2–10-flowered, hemispheric or narrower, 5–10 mm diam.	terminal racemes of 2–9 heads, 2–10 cm, branches erect; primary bract erect; heads 2–12-flowered, obconic or rarely hemispheric, 4–13 mm diam.
Flowers	tepals green to straw-colored, lanceolate, apex acute; outer tepals (2–)2.6–3.2 mm; inner tepals (1.8–)2.3–3 mm; stamens 3, anthers 1/2–2/3 filament length.	tepals light brown or greenish to reddish brown, linear to narrowly lanceolate, apex acute to acuminate-subulate; outer tepals (2.1–)2.8–4.9 mm; inner tepals (2.1–)2.8–5.5 mm; stamens 3 or 6, anthers 1/2–3/4 filament length.
Capsules	exserted, , straw-colored, 1-locular, linear-lanceoloid, 4–5.2 mm, apex acute, valves separating at dehiscence.	usually exserted, dark brown, 1-locular, ovoid to oblong, (3.2–)3.5–6.1 mm, apex acute to acuminate proximal to beak, valves separating at dehiscence.
Seeds	oblong-ellipsoid, 0.3–0.4 mm, not tailed; body clear yellow-brown.	narrowly obovoid to obovoid, 0.6–0.7 mm, not tailed; body clear yellow-brown..
n		= ca. 30, ca. 50–60, 2n = ca. 112.

	Juncus diffusissimus	Juncus supiniformis
Phenology	Fruiting summer.	Fruiting mid summer–fall.
Habitat	In soft mucky substrates, marshy shores, sloughs, occasionally in wet wooded places, often in shallow water, commonly abundantly colonizing wet, sandy- alluvial outwash in ditches and clearings	Pond, lake and river shores, marshes, bogs, and ditches
Elevation	10–1000 m (0–3300 ft)	0–1000 m (0–3300 ft)
Distribution	AL; AR; CA; CT; FL; GA; IL; IN; KS; KY; LA; MD; MO; MS; NC; OH; OK; SC; TN; TX; VA; WA; WV [Probably introduced, South America] [WildflowerSearch map] [BONAP county map]	AK; CA; OR; WA; BC [WildflowerSearch map] [BONAP county map]
Discussion		The northern California and southern Oregon populations (Juncus supiniformis in the strict sense) form long filiform leaves before flowering, are shorter, and have smaller flowers than the northern populations. Except for the filiform leaves, the variation in sizes appears to follow a rough latitudinal cline with the largest plants and largest flowers in Alaska. Flowers of Juncus supiniformis often form bulbils. (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. Septati
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. 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. roemerianus, J. scirpoides, J. secundus, J. squarrosus, J. stygius, J. subcaudatus, J. subtilis, 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. oreganus, J. paucicapitatus
Name authority	Buckley: Proceedings of the Academy of Natural Sciences of Philadelphia 14: 9. (1862)	Engelmann
Web links	Local floras: CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, Go Botany, IL Wildflowers, KS Wildflowers, LA Plants, MD Biodiversity, 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	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, 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 supiniformis

diffuse rush, slim-fruit rush, slim-pod rush

hair-leaf rush, hairy-leaf rush, spreading rush

Habit

Herbs, perennial, cespitose, 2.5–6.5 dm.

Herbs, perennial, cespitose or matted, often decumbent, rooting at proximal nodes or floating, 0.3–5 dm.

Culms

erect, terete, 1–3 mm diam., smooth.

erect, decumbent and rooting at nodes, or floating, terete, 1–2 mm diam., smooth.

Cataphylls

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

0 or 1–2, straw-colored, apex acute.

Leaves

basal 1, cauline 2–3;

auricles 1–2.1 mm, apex rounded, membranaceous;

blade maroon or dark green, terete to compressed, 3–20 cm × 1–2.4 mm.

basal 1–3, cauline 1–4;

auricles 0.8–2.1 mm, apex rounded to acute, membranaceous;

blade terete, 3.7–15 cm × 0.4–1.3 mm, occasionally with filiform, flaccid, and floating leaves to 60 cm.

Inflorescences

terminal panicles of 30–70(–130), 5–20 cm, branches spreading;

primary bract erect;

;

heads (1–)2–10-flowered, hemispheric or narrower, 5–10 mm diam.

terminal racemes of 2–9 heads, 2–10 cm, branches erect;

primary bract erect;

heads 2–12-flowered, obconic or rarely hemispheric, 4–13 mm diam.

Flowers

tepals green to straw-colored, lanceolate, apex acute;

outer tepals (2–)2.6–3.2 mm;

inner tepals (1.8–)2.3–3 mm;

stamens 3, anthers 1/2–2/3 filament length.

tepals light brown or greenish to reddish brown, linear to narrowly lanceolate, apex acute to acuminate-subulate;

outer tepals (2.1–)2.8–4.9 mm;

inner tepals (2.1–)2.8–5.5 mm;

stamens 3 or 6, anthers 1/2–3/4 filament length.

Capsules

exserted, , straw-colored, 1-locular, linear-lanceoloid, 4–5.2 mm, apex acute, valves separating at dehiscence.

usually exserted, dark brown, 1-locular, ovoid to oblong, (3.2–)3.5–6.1 mm, apex acute to acuminate proximal to beak, valves separating at dehiscence.

Seeds

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

body clear yellow-brown.

narrowly obovoid to obovoid, 0.6–0.7 mm, not tailed;

body clear yellow-brown..

= ca. 30, ca. 50–60, 2n = ca. 112.

Juncus supiniformis

Phenology

Fruiting summer.

Fruiting mid summer–fall.

Habitat

In soft mucky substrates, marshy shores, sloughs, occasionally in wet wooded places, often in shallow water, commonly abundantly colonizing wet, sandy- alluvial outwash in ditches and clearings

Pond, lake and river shores, marshes, bogs, and ditches

Elevation

10–1000 m (0–3300 ft)

0–1000 m (0–3300 ft)

Distribution

AL; AR; CA; CT; FL; GA; IL; IN; KS; KY; LA; MD; MO; MS; NC; OH; OK; SC; TN; TX; VA; WA; WV [Probably introduced, South America]

[WildflowerSearch map]

[BONAP county map]

AK; CA; OR; WA; BC

[WildflowerSearch map]

[BONAP county map]

Discussion

The northern California and southern Oregon populations (Juncus supiniformis in the strict sense) form long filiform leaves before flowering, are shorter, and have smaller flowers than the northern populations. Except for the filiform leaves, the variation in sizes appears to follow a rough latitudinal cline with the largest plants and largest flowers in Alaska.

Flowers of Juncus supiniformis often form bulbils.

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

Source

FNA vol. 22.

Parent taxa

Juncaceae > Juncus > subg. Septati

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. 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. roemerianus, J. scirpoides, J. secundus, J. squarrosus, J. stygius, J. subcaudatus, J. subtilis, 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. oreganus, J. paucicapitatus

Name authority

Buckley: Proceedings of the Academy of Natural Sciences of Philadelphia 14: 9. (1862)

Engelmann

Web links

Local floras: CA, OR, WA
Local Web sites: CalFlora, CalPhotos, Flora NW, Go Botany, IL Wildflowers, KS Wildflowers, LA Plants, MD Biodiversity, 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

Local floras: BC, CA, OR, WA
Local Web sites: CalFlora, CalPhotos, Flora NW, 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

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Flora of North America species comparison

Juncus diffusissimus

Juncus supiniformis

Juncus diffusissimus

Juncus supiniformis