OregonFlora: Juncus trilocularis vs. Juncus bulbosus

	Juncus trilocularis	Juncus bulbosus
	foothill rush	bulbous rush, spreading rush
Habit	Plants perennial, 10–78 cm tall, cespitose, lacking strong stem ridges.	Plants perennial, sometimes flowering in the first year, 1–30 cm tall, cespitose, sometimes tuberous at nodes, stems sometimes prostrate, trailing, stoloniferous, rooting at nodes, upper nodes sometimes forming leafy bulblets.
Leaves	thin and wiry; blade flat and slightly inrolled; auricles soft and thin distally, 0.3–3 mm; dull, rounded or acute; dirty white.	round; hollow or several-chambered, septate at least in part; auricles 1–2 mm.
Inflorescences	cymes, 2–20 cm, usually open; bractlets subtending flowers acute to acuminate, often aristate.	open; (2)6–16 clusters; clusters 2–12-flowered; flowers often forming leafy bulblets.
Flowers	tepals 6, 3.3–5.1 mm; greenish to pale brown, nearly concolorous; tips acuminate; outer tepals distinctly longer than inner tepals; stamens 6; filaments 0.5–0.8 mm; anthers (0.6)0.8–1.7 mm; styles 0.3–1 mm.	tepals 6, 1.8–3.4 mm, green, red, or brown (dark brown); inner tepal margins flat; tips usually blunt, hooded; stamens (3)6; filaments 0.6–1 mm; longer than or equaling anthers; anthers 0.2–0.8 mm; styles 0.2–0.5 mm.
Capsules	2.8–4.1 mm; shorter than the tepals, pale brown to dark brown; apex truncate to notched (acute), crested, 3-chambered.	usually 0.1–0.4 mm longer than or equaling tepals, brown to dark brown, abruptly tapered to apices; blunt or acute, 1-chambered.
Seeds	0.4–0.6 × 0.2–0.3 mm, apiculate, reticulate.	ellipsoid to ovoid, 0.4–0.6 × 0.2–0.25 mm, apiculate.
2n		=40.

	Juncus trilocularis	Juncus bulbosus
Distribution	[WildflowerSearch map] [BONAP county map]	[BONAP county map]
Discussion	Seasonally damp meadows, springs, shores, creek banks, moist open forest, ditches. 300–1900m. BW, Col, ECas, Owy, Sisk, Casc. CA, ID, NV, WA. Native. This is an uncommon species found east of the Cascade Range and in the Siskiyou Mountains that has long been confused with Juncus brachyphyllus, a plant of grasslands and glades in the Midwest, which occurs no further west than Nebraska.	Damp grassy disturbed ground, lakeshores. 0–50 m. Est. CA, WA; north to British Columbia, northeastern Canada and NY; Australia, Europe, Mauritius, New Zealand. Exotic. This species is uncommon but can invade natural wetland systems. The capsule is rounded at the tip, differing from the acute to acuminate capsules of J. supiniformis. Juncus supiniformis capsules are more than 1 mm longer than the tepals. Juncus articulatus is coarser and has capsules more exserted than J. bulbosus.
Source	Flora of Oregon, volume 1, page 284 Peter Zika	Flora of Oregon, volume 1, page 273 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. supiniformis, J. tenuis, J. tiehmii, J. torreyi, J. triglumis, J. uncialis	J. acuminatus, J. anthelatus, J. articulatus, J. balticus, J. bolanderi, J. brevicaudatus, J. breweri, J. bryoides, J. bufonius, 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. supiniformis, J. tenuis, J. tiehmii, J. torreyi, J. triglumis, J. trilocularis, J. uncialis
Synonyms	Juncus brachyphyllus	Juncus supinus
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 bulbosus

foothill rush

bulbous rush, spreading rush

Habit

Plants perennial, 10–78 cm tall, cespitose, lacking strong stem ridges.

Plants perennial, sometimes flowering in the first year, 1–30 cm tall, cespitose, sometimes tuberous at nodes, stems sometimes prostrate, trailing, stoloniferous, rooting at nodes, upper nodes sometimes forming leafy bulblets.

Leaves

thin and wiry;

blade flat and slightly inrolled;

auricles soft and thin distally, 0.3–3 mm; dull, rounded or acute; dirty white.

round; hollow or several-chambered, septate at least in part;

auricles 1–2 mm.

Inflorescences

cymes, 2–20 cm, usually open;

bractlets subtending flowers acute to acuminate, often aristate.

open; (2)6–16 clusters; clusters 2–12-flowered;

flowers often forming leafy bulblets.

Flowers

tepals 6, 3.3–5.1 mm; greenish to pale brown, nearly concolorous;

tips acuminate;

outer tepals distinctly longer than inner tepals;

stamens 6;

filaments 0.5–0.8 mm;

anthers (0.6)0.8–1.7 mm;

styles 0.3–1 mm.

tepals 6, 1.8–3.4 mm, green, red, or brown (dark brown);

inner tepal margins flat;

tips usually blunt, hooded;

stamens (3)6;

filaments 0.6–1 mm; longer than or equaling anthers;

anthers 0.2–0.8 mm;

styles 0.2–0.5 mm.

Capsules

2.8–4.1 mm; shorter than the tepals, pale brown to dark brown;

apex truncate to notched (acute), crested, 3-chambered.

usually 0.1–0.4 mm longer than or equaling tepals, brown to dark brown, abruptly tapered to apices; blunt or acute, 1-chambered.

Seeds

0.4–0.6 × 0.2–0.3 mm, apiculate, reticulate.

ellipsoid to ovoid, 0.4–0.6 × 0.2–0.25 mm, apiculate.

=40.

Juncus trilocularis

Juncus bulbosus

Distribution

[WildflowerSearch map]

[BONAP county map]

Discussion

Seasonally damp meadows, springs, shores, creek banks, moist open forest, ditches. 300–1900m. BW, Col, ECas, Owy, Sisk, Casc. CA, ID, NV, WA. Native.

This is an uncommon species found east of the Cascade Range and in the Siskiyou Mountains that has long been confused with Juncus brachyphyllus, a plant of grasslands and glades in the Midwest, which occurs no further west than Nebraska.

Damp grassy disturbed ground, lakeshores. 0–50 m. Est. CA, WA; north to British Columbia, northeastern Canada and NY; Australia, Europe, Mauritius, New Zealand. Exotic.

This species is uncommon but can invade natural wetland systems. The capsule is rounded at the tip, differing from the acute to acuminate capsules of J. supiniformis. Juncus supiniformis capsules are more than 1 mm longer than the tepals. Juncus articulatus is coarser and has capsules more exserted than J. bulbosus.

Source

Flora of Oregon, volume 1, page 284
Peter Zika

Flora of Oregon, volume 1, page 273
Peter Zika

Sibling taxa