OregonFlora: Juncus howellii vs. Juncus ensifolius

	Juncus howellii	Juncus ensifolius
	Howell's rush	dagger-leaved rush, swordleaf rush
Habit	Plants perennial, 20–60 cm tall, rhizomatous.	Plants perennial, 15–65 cm tall, rhizomatous.
Leaves	flat; grass-like, blue-green; up to 4.5 mm wide; auricles absent or 0.2– 2 mm.	flat; iris-like, blue-green, partially septate; auricles usually absent (0.1–0.4 mm).
Inflorescences	(2)5–20 clusters; clusters usually 2–8-flowered.	1–12(22) clusters; clusters often head-like, 3–70-flowered.
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 to often dark brown or black; stamens 3; filaments 0.6–1.1 mm; anthers 0.4–0.7 mm; styles 0.2–0.8(1) mm.
Capsules	obovoid; shorter than the tepals, brown; acute, 3-chambered.	longer than or equaling tepals, dark brown to blackish; apices obtuse or acute and abruptly tapered to short beak, 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.	0.4–0.5(0.6) × 0.15–0.2 mm, apiculate, reticulate.

	Juncus howellii	Juncus ensifolius
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.	Shores, swales, springs, wet meadows, wet prairie, damp dunes, peatlands, ditches. 0–2500m. Throughout Oregon. CA, ID, NV, WA; north to Alaska, east to Saskatchewan, SD and CO, south to AZ and Mexico; Ontario and Quebec south to WI and NY; HI; northeastern Asia, Europe, New Zealand. Native. With three stamens, this species is reliably separated from J. saximontanus, which has six stamens. Rare plants with variable stamen numbers in an inflorescence may represent hybrids and need investigation.
Source	Flora of Oregon, volume 1, page 279 Peter Zika	Flora of Oregon, volume 1, page 277 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 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 ensifolius var. ensifolius, Juncus tracyi
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 ensifolius

Howell's rush

dagger-leaved rush, swordleaf rush

Habit

Plants perennial, 20–60 cm tall, rhizomatous.

Plants perennial, 15–65 cm tall, rhizomatous.

Leaves

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

auricles absent or 0.2– 2 mm.

flat; iris-like, blue-green, partially septate;

auricles usually absent (0.1–0.4 mm).

Inflorescences

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

1–12(22) clusters; clusters often head-like, 3–70-flowered.

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 to often dark brown or black;

stamens 3;

filaments 0.6–1.1 mm;

anthers 0.4–0.7 mm;

styles 0.2–0.8(1) mm.

Capsules

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

longer than or equaling tepals, dark brown to blackish;

apices obtuse or acute and abruptly tapered to short beak, 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.

0.4–0.5(0.6) × 0.15–0.2 mm, apiculate, reticulate.

Juncus ensifolius

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.

Shores, swales, springs, wet meadows, wet prairie, damp dunes, peatlands, ditches. 0–2500m. Throughout Oregon. CA, ID, NV, WA; north to Alaska, east to Saskatchewan, SD and CO, south to AZ and Mexico; Ontario and Quebec south to WI and NY; HI; northeastern Asia, Europe, New Zealand. Native.

With three stamens, this species is reliably separated from J. saximontanus, which has six stamens. Rare plants with variable stamen numbers in an inflorescence may represent hybrids and need investigation.

Source

Flora of Oregon, volume 1, page 279
Peter Zika

Flora of Oregon, volume 1, page 277
Peter Zika

Sibling taxa