OregonFlora: Juncus brachycephalus vs. Juncus bulbosus

	Juncus brachycephalus	Juncus bulbosus
		bulbous rush, spreading rush
Habit		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		round; hollow or several-chambered, septate at least in part; auricles 1–2 mm.
Inflorescences		open; (2)6–16 clusters; clusters 2–12-flowered; flowers often forming leafy bulblets.
Flowers		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 0.1–0.4 mm longer than or equaling tepals, brown to dark brown, abruptly tapered to apices; blunt or acute, 1-chambered.
Seeds		ellipsoid to ovoid, 0.4–0.6 × 0.2–0.25 mm, apiculate.
2n		=40.

	Juncus brachycephalus	Juncus bulbosus
Distribution	[WildflowerSearch map] [BONAP county map]	[BONAP county map]
Discussion		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 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. 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 supinus
Web links	Local Web sites: 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 brachycephalus

Juncus bulbosus

bulbous rush, spreading rush

Habit

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

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

auricles 1–2 mm.

Inflorescences

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

flowers often forming leafy bulblets.

Flowers

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

Seeds

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

=40.

Juncus brachycephalus

Juncus bulbosus

Distribution

[WildflowerSearch map]

[BONAP county map]

Discussion

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 273
Peter Zika

Sibling taxa