OregonFlora species comparison

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Juncus confusus

Juncus filiformis

Colorado rush

thread rush
Habit Plants perennial, 20–50 cm tall, cespitose, stems with 0–5 strong ridges visible on one side. Plants perennial, 10–80 cm tall, rhizomatous, stem ridges obscure.
Leaves

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.

lacking blades;

distal sheaths 3–10 cm, light brown.
Inflorescences

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

a more or less loose cluster of 4–15 flowers, usually attached near or below middle of stems (stems here including erect inflorescence bracts above inflorescences);

inflorescence bracts not swollen at base.
Flowers

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.

tepals 6, green or pale brown, 2.5–4 mm;

stamens 6;

filaments 0.4–0.9 mm;

anthers 0.3–0.6 mm;

styles 0.1– 0.15 mm.
Capsules

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

apex notched, crested, 3-chambered.

2.5–3.5 mm; shorter than or equaling the length of the tepals, green to light brown;

apex obtuse to acute, 3-chambered.
Seeds

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

0.4–0.5 × 0.2–0.25 mm.
2n

=80.

=70, 80, 84.

Juncus confusus

Juncus filiformis
Distribution
[WildflowerSearch map]
[BONAP county map]
[WildflowerSearch map]
[BONAP county map]
Discussion

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.

Pond shores, wet meadows, marshes. 800–2300 m. BW, Casc. ID, WA; northern North America; Eurasia. Native.
Source Flora of Oregon, volume 1, page 274
Peter Zika		 Flora of Oregon, volume 1, page 278
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. 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
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. 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
Web links 
Unless otherwise noted, all data comes from OregonFlora.



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