OregonFlora: Juncus uncialis vs. Juncus bulbosus

	Juncus uncialis	Juncus bulbosus
	inch-high rush, twelfth rush	bulbous rush, spreading rush
Habit	Plants annual, 0.3–3.5 cm tall, unbranched, stems not thickened below flowers.	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	capillary; basal.	round; hollow or several-chambered, septate at least in part; auricles 1–2 mm.
Inflorescences	1 terminal flower, subtended by solitary bractlet; base encircling stem; tip truncate.	open; (2)6–16 clusters; clusters 2–12-flowered; flowers often forming leafy bulblets.
Flowers	tepals usually 6 (4 or 8), green or reddish; stamens (2)3; filaments 0.9–1.6 mm; anthers 0.3–0.5 mm; styles 0.1–0.3 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	usually shorter than or equaling the tepals; (green) orange; reddish or dark purple and often darker than tepals.	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	approximately 100–140 per capsule, 0.3–0.4 × 0.15–0.25 mm, sometimes faintly reticulate (at 10×), not striate.	ellipsoid to ovoid, 0.4–0.6 × 0.2–0.25 mm, apiculate.
2n	=32.	=40.

	Juncus uncialis	Juncus bulbosus
Distribution	[WildflowerSearch map] [BONAP county map]	[BONAP county map]
Discussion	Vernal pools, shores exposed by receding water, stony swales. 50–2700m. BR, Col, ECas, Sisk. CA, NV, WA. Native.	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. trilocularis	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 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

inch-high rush, twelfth rush

bulbous rush, spreading rush

Habit

Plants annual, 0.3–3.5 cm tall, unbranched, stems not thickened below flowers.

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

capillary;

basal.

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

auricles 1–2 mm.

Inflorescences

1 terminal flower, subtended by solitary bractlet;

base encircling stem;

tip truncate.

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

flowers often forming leafy bulblets.

Flowers

tepals usually 6 (4 or 8), green or reddish;

stamens (2)3;

filaments 0.9–1.6 mm;

anthers 0.3–0.5 mm;

styles 0.1–0.3 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

usually shorter than or equaling the tepals; (green) orange; reddish or dark purple and often darker than tepals.

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

approximately 100–140 per capsule, 0.3–0.4 × 0.15–0.25 mm, sometimes faintly reticulate (at 10×), not striate.

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

=32.

=40.

Juncus uncialis

Juncus bulbosus

Distribution

[WildflowerSearch map]

[BONAP county map]

Discussion

Vernal pools, shores exposed by receding water, stony swales. 50–2700m. BR, Col, ECas, Sisk. CA, NV, WA. Native.

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