OregonFlora: Juncus ranarius vs. Juncus confusus

	Juncus ranarius	Juncus confusus
	frog rush	Colorado rush
Habit	Plants annual, 3–10(17)cm tall, branched.	Plants perennial, 20–50 cm tall, cespitose, stems with 0–5 strong ridges visible on one side.
Leaves	usually less than 1 mm wide; stem leaves usually 1–2.	thin and wiry; blade flat and slightly inrolled; auricles soft and thin distally, 0.3–0.8 mm; dull, rounded or acute; dirty white to translucent.
Inflorescences	cymose; flowers solitary at nodes.	cymes, 0.5–2.5 cm, usually dense and small.
Flowers	tepals 6, green to light brown; outer tepals usually 4–5 mm; inner more or less blunt; stamens 6; filaments 0.7– 1.5 mm; anthers 0.4–0.8 mm; styles 0.3–0.4 mm.	tepals 6, with broad medium brown stripes flanking a green midvein; tepal tips acuminate; erect; equal or subequal; stamens 6; filaments 0.7–1.1 mm; anthers 0.5–0.7 mm; styles 0.05–0.2 mm.
Capsules	usually truncate (blunt to subacute); (shorter than) more or less equaling inner tepals, brown, 1-chambered.	2.5–3.5 mm; shorter than or equaling tepals, brown to dark brown; apex notched, crested, 3-chambered.
Seeds	0.35–0.5 × 0.25–0.35 mm, apiculate.	0.4–0.5 × 0.2–0.3 mm, apiculate, longitudinally ridged.
2n	=34.	=80.

	Juncus ranarius	Juncus confusus
Distribution		[WildflowerSearch map] [BONAP county map]
Discussion	Moist clay, stream banks, disturbed wet ground. 0–2000m. BR. CA; scattered across North America; North Africa, Eurasia. Exotic. Juncus ranarius is similar to J. bufonius, as well as Eurasian J. ambiguus, a misapplied name in our flora. The taxonomy of these species is controversial (Balslev 1996), and the complex needs worldwide revision. It is presumably exotic in North America and easily overlooked.	Seasonally moist or wet meadows, springs, swales, shores, ditches. 800–2700 m. BR, BW, ECas, Owy, Sisk. CA, NV, ID, WA; north to British Columbia, east to SD, southeast to NM. Native. This species is often confused with Juncus occidentalis, which shares the brown-striped tepals and crested capsules but does not grow east of the Cascades. Where they overlap in southwestern Oregon and California, they are separable by the internal structure of the capsules: three-chambered in J. confusus and one-chambered in J. occidentalis.
Source	Flora of Oregon, volume 1, page 283 Peter Zika	Flora of Oregon, volume 1, page 274 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. regelii, J. saximontanus, J. supiniformis, J. tenuis, J. tiehmii, J. torreyi, J. triglumis, J. trilocularis, J. uncialis	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. 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. supiniformis, J. tenuis, J. tiehmii, J. torreyi, J. triglumis, J. trilocularis, J. uncialis
Synonyms	Juncus ambiguus, Juncus bufonius var. halophilus
Web links	Local floras: CA, OR 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	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 confusus

frog rush

Colorado rush

Habit

Plants annual, 3–10(17)cm tall, branched.

Plants perennial, 20–50 cm tall, cespitose, stems with 0–5 strong ridges visible on one side.

Leaves

usually less than 1 mm wide;

stem leaves usually 1–2.

thin and wiry;

blade flat and slightly inrolled;

auricles soft and thin distally, 0.3–0.8 mm; dull, rounded or acute; dirty white to translucent.

Inflorescences

cymose;

flowers solitary at nodes.

cymes, 0.5–2.5 cm, usually dense and small.

Flowers

tepals 6, green to light brown;

outer tepals usually 4–5 mm; inner more or less blunt;

stamens 6;

filaments 0.7– 1.5 mm;

anthers 0.4–0.8 mm;

styles 0.3–0.4 mm.

tepals 6, with broad medium brown stripes flanking a green midvein;

tepal tips acuminate; erect; equal or subequal;

stamens 6;

filaments 0.7–1.1 mm;

anthers 0.5–0.7 mm;

styles 0.05–0.2 mm.

Capsules

usually truncate (blunt to subacute); (shorter than) more or less equaling inner tepals, brown, 1-chambered.

2.5–3.5 mm; shorter than or equaling tepals, brown to dark brown;

apex notched, crested, 3-chambered.

Seeds

0.35–0.5 × 0.25–0.35 mm, apiculate.

0.4–0.5 × 0.2–0.3 mm, apiculate, longitudinally ridged.

=34.

=80.

Juncus confusus

Distribution

[WildflowerSearch map]

[BONAP county map]

Discussion

Moist clay, stream banks, disturbed wet ground. 0–2000m. BR. CA; scattered across North America; North Africa, Eurasia. Exotic.

Juncus ranarius is similar to J. bufonius, as well as Eurasian J. ambiguus, a misapplied name in our flora. The taxonomy of these species is controversial (Balslev 1996), and the complex needs worldwide revision. It is presumably exotic in North America and easily overlooked.

Seasonally moist or wet meadows, springs, swales, shores, ditches. 800–2700 m. BR, BW, ECas, Owy, Sisk. CA, NV, ID, WA; north to British Columbia, east to SD, southeast to NM. Native.

This species is often confused with Juncus occidentalis, which shares the brown-striped tepals and crested capsules but does not grow east of the Cascades. Where they overlap in southwestern Oregon and California, they are separable by the internal structure of the capsules: three-chambered in J. confusus and one-chambered in J. occidentalis.

Source

Flora of Oregon, volume 1, page 283
Peter Zika

Flora of Oregon, volume 1, page 274
Peter Zika

Sibling taxa