OregonFlora: Juncus howellii vs. Juncus occidentalis

	Juncus howellii	Juncus occidentalis
	Howell's rush	prairie rush, western rush
Habit	Plants perennial, 20–60 cm tall, rhizomatous.	Plants perennial, 30–60 cm tall, cespitose, 0–3(5) strong stem ridges visible per side.
Leaves	flat; grass-like, blue-green; up to 4.5 mm wide; auricles absent or 0.2– 2 mm.	thin and wiry; blade flat and slightly inrolled; auricles soft and thin distally, 0.1– 1.1 mm; dull, rounded or acute; dirty white.
Inflorescences	(2)5–20 clusters; clusters usually 2–8-flowered.	cymes, 1–7 cm; bractlets subtending flowers blunt to acute.
Flowers	tepals 6, dark brown, papillose; inner usually longer than the outer; stamens 6; filaments 0.6–1.1 mm; anthers 1.2–2.6 mm; styles 1.2–3.2 mm.	tepals 6, brown-striped; tepal tips acuminate; stamens 6; filaments 0.6–1.1 mm; anthers 0.4–0.9 mm; styles 0.1–0.3 mm.
Capsules	obovoid; shorter than the tepals, brown; acute, 3-chambered.	2.7–4.5 mm; shorter than the tepals, brown; apex usually truncate to slightly notched, strongly ridged or crested distally, 1-chambered.
Seeds	slender, 0.6–1 × 0.25– 0.3 mm; body 0.4–0.6 mm; tail 0.1–0.3 mm, 1 or 2 tails at least half the length of the seed body.	0.4–0.6 × 0.2– 0.25 mm, apiculate.
2n		=80.

	Juncus howellii	Juncus occidentalis
Distribution	[WildflowerSearch map] [BONAP county map]	[WildflowerSearch map] [BONAP county map]
Discussion	Springs, gravel bars, wet slopes, peatlands. 600–2200m. BW, Casc. CA, ID, WA. Native. Auricle characters are occasionally unreliable, so this species is best separated from J. orthophyllus and J. regelii by the intermediate length of the tail on the seed, with one or both seed tails about half as long as the seed body. Juncus orthophyllus has apiculate seeds without a tail, and J. regelii has seed tails approximately as long as the seed body.	Wet prairies, swales, shores, riparian zones, seeps, wet meadows, balds, vernal pools, ditches. 0–2100 m. CR, ECas, Est, Sisk, WV. CA, WA; British Columbia, Baja California Norte, Mexico. Native. Juncus occidentalis is a western Oregon sister species to J. confusus, separable by the construction of the capsules (threechambered in J. confusus, one-chambered in J. occidentalis).
Source	Flora of Oregon, volume 1, page 279 Peter Zika	Flora of Oregon, volume 1, page 281 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. 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. 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. 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 tenuis var. congestus
Web links	Local floras: 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	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 occidentalis

Howell's rush

prairie rush, western rush

Habit

Plants perennial, 20–60 cm tall, rhizomatous.

Plants perennial, 30–60 cm tall, cespitose, 0–3(5) strong stem ridges visible per side.

Leaves

flat; grass-like, blue-green; up to 4.5 mm wide;

auricles absent or 0.2– 2 mm.

thin and wiry;

blade flat and slightly inrolled;

auricles soft and thin distally, 0.1– 1.1 mm; dull, rounded or acute; dirty white.

Inflorescences

(2)5–20 clusters; clusters usually 2–8-flowered.

cymes, 1–7 cm;

bractlets subtending flowers blunt to acute.

Flowers

tepals 6, dark brown, papillose; inner usually longer than the outer;

stamens 6;

filaments 0.6–1.1 mm;

anthers 1.2–2.6 mm;

styles 1.2–3.2 mm.

tepals 6, brown-striped;

tepal tips acuminate;

stamens 6;

filaments 0.6–1.1 mm;

anthers 0.4–0.9 mm;

styles 0.1–0.3 mm.

Capsules

obovoid; shorter than the tepals, brown; acute, 3-chambered.

2.7–4.5 mm; shorter than the tepals, brown;

apex usually truncate to slightly notched, strongly ridged or crested distally, 1-chambered.

Seeds

slender, 0.6–1 × 0.25– 0.3 mm;

body 0.4–0.6 mm; tail 0.1–0.3 mm, 1 or 2 tails at least half the length of the seed body.

0.4–0.6 × 0.2– 0.25 mm, apiculate.

=80.

Juncus occidentalis

Distribution

[WildflowerSearch map]

[BONAP county map]

[WildflowerSearch map]

[BONAP county map]

Discussion

Springs, gravel bars, wet slopes, peatlands. 600–2200m. BW, Casc. CA, ID, WA. Native.

Auricle characters are occasionally unreliable, so this species is best separated from J. orthophyllus and J. regelii by the intermediate length of the tail on the seed, with one or both seed tails about half as long as the seed body. Juncus orthophyllus has apiculate seeds without a tail, and J. regelii has seed tails approximately as long as the seed body.

Wet prairies, swales, shores, riparian zones, seeps, wet meadows, balds, vernal pools, ditches. 0–2100 m. CR, ECas, Est, Sisk, WV. CA, WA; British Columbia, Baja California Norte, Mexico. Native.

Juncus occidentalis is a western Oregon sister species to J. confusus, separable by the construction of the capsules (threechambered in J. confusus, one-chambered in J. occidentalis).

Source

Flora of Oregon, volume 1, page 279
Peter Zika

Flora of Oregon, volume 1, page 281
Peter Zika

Sibling taxa