OregonFlora: Juncus supiniformis

	Juncus supiniformis
	hair-leaved rush, spreading rush
Habit	Plants perennial, 3–50 cm tall, cespitose, forming mats if submerged, sometimes stoloniferous with stems trailing and rooting at nodes.
Leaves	numerous; capillary, 0.2– 0.3 mm wide if aquatic; round; hollow, septate; auricles 0.8–2.1 mm.
Inflorescences	open, cymes of 2–9 clusters; clusters 2–5(12)-flowered, often bearing leafy bulblets.
Flowers	tepals 6, 3.4–5.4 mm, brown; greenish or reddish; inner tepal margins usually inrolled; tips acuminate; stamens 3 or 6; filaments 0.8–1.5 mm; anthers 0.5–0.8 mm; styles 0.1–0.4 mm.
Capsules	usually 1–1.5 mm longer than the tepals, brown to dark brown; without metallic gloss, 1-chambered.
Seeds	ellipsoid to ovoid, 0.6–1 × 0.2–0.3 mm, apiculate, striate.

	Juncus supiniformis
Distribution	[WildflowerSearch map] [BONAP county map]
Discussion	Shores, peatlands, marshes, wet dune hollows, often in shallow water. 0–1100 m. Est, Casc. CA, WA, north to AK. Native. Like introduced Juncus bulbosus, this species can bear bulblets in the inflorescence, and both are variable in habit depending on water levels. They differ in the shape of the tepal tips and length of the capsules. Juncus articulatus is similar but has blunter tepal tips and is common on disturbed wet ground.
Source	Flora of Oregon, volume 1, page 283 Peter Zika
Sibling taxa	J. acuminatus, J. anthelatus, J. articulatus, J. balticus, J. bolanderi, J. brevicaudatus, J. breweri, J. bryoides, J. bufonius, J. bulbosus, J. canadensis, J. capillaris, J. capitatus, J. compressus, J. confusus, J. conglomeratus, J. covillei, J. diffusissimus, J. drummondii, J. dudleyi, J. effusus, J. ensifolius, J. ensifolius x Juncus nevadensis, J. exiguus, J. falcatus, J. filiformis, J. gerardi, J. hemiendytus, J. hesperius, J. howellii, J. inflexus, J. interior, J. kelloggii, J. laccatus, J. lescurii, J. longistylis, J. marginatus, J. mertensianus, J. mexicanus, J. nevadensis, J. occidentalis, J. orthophyllus, J. oxymeris, J. parryi, J. patens, J. pelocarpus, J. planifolius, J. ranarius, J. regelii, J. saximontanus, J. tenuis, J. tiehmii, J. torreyi, J. triglumis, J. trilocularis, J. uncialis
Synonyms	Juncus oreganus
Web links	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

hair-leaved rush, spreading rush

Habit

Plants perennial, 3–50 cm tall, cespitose, forming mats if submerged, sometimes stoloniferous with stems trailing and rooting at nodes.

Leaves

numerous; capillary, 0.2– 0.3 mm wide if aquatic; round; hollow, septate;

auricles 0.8–2.1 mm.

Inflorescences

open, cymes of 2–9 clusters; clusters 2–5(12)-flowered, often bearing leafy bulblets.

Flowers

tepals 6, 3.4–5.4 mm, brown; greenish or reddish;

inner tepal margins usually inrolled;

tips acuminate;

stamens 3 or 6;

filaments 0.8–1.5 mm;

anthers 0.5–0.8 mm;

styles 0.1–0.4 mm.

Capsules

usually 1–1.5 mm longer than the tepals, brown to dark brown; without metallic gloss, 1-chambered.

Seeds

ellipsoid to ovoid, 0.6–1 × 0.2–0.3 mm, apiculate, striate.

Juncus supiniformis

Distribution

[WildflowerSearch map]

[BONAP county map]

Discussion

Shores, peatlands, marshes, wet dune hollows, often in shallow water. 0–1100 m. Est, Casc. CA, WA, north to AK. Native.

Like introduced Juncus bulbosus, this species can bear bulblets in the inflorescence, and both are variable in habit depending on water levels. They differ in the shape of the tepal tips and length of the capsules. Juncus articulatus is similar but has blunter tepal tips and is common on disturbed wet ground.

Source

Flora of Oregon, volume 1, page 283
Peter Zika

Sibling taxa

J. acuminatus, J. anthelatus, J. articulatus, J. balticus, J. bolanderi, J. brevicaudatus, J. breweri, J. bryoides, J. bufonius, J. bulbosus, J. canadensis, J. capillaris, J. capitatus, J. compressus, J. confusus, J. conglomeratus, J. covillei, J. diffusissimus, J. drummondii, J. dudleyi, J. effusus, J. ensifolius, J. ensifolius x Juncus nevadensis, J. exiguus, J. falcatus, J. filiformis, J. gerardi, J. hemiendytus, J. hesperius, J. howellii, J. inflexus, J. interior, J. kelloggii, J. laccatus, J. lescurii, J. longistylis, J. marginatus, J. mertensianus, J. mexicanus, J. nevadensis, J. occidentalis, J. orthophyllus, J. oxymeris, J. parryi, J. patens, J. pelocarpus, J. planifolius, J. ranarius, J. regelii, J. saximontanus, J. tenuis, J. tiehmii, J. torreyi, J. triglumis, J. trilocularis, J. uncialis

Synonyms

Juncus oreganus

Web links

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 OregonFlora.

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

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Juncus supiniformis

Juncus supiniformis