OregonFlora: Juncus tiehmii

	Juncus tiehmii
	Tiehm's dwarf rush
Habit	Plants annual, 0.5–6 cm tall, unbranched.
Leaves	capillary; basal.
Inflorescences	1–4(7) flowers in a terminal cluster; flowers subtended by 2 bractlets; tips acute.
Flowers	tepals usually 4, pale green or pink; stamens 2(3); filaments 0.6–0.9 mm; anthers 0.3–0.4 mm; styles 0.1– 0.3 mm.
Capsules	usually elliptic to oblong, equaling or longer than the tepals, pale green or pink.
Seeds	up to 7 per chamber, 12–30 per capsule, 0.3–0.5 × 0.2–0.3 mm, longitudinally striate (at 10×).
2n	=34.

	Juncus tiehmii
Distribution	[BONAP county map]
Discussion	Damp depressions, stream banks, sunny floodplains. 1000– 2000m. BR, ECas. CA, NV, ID, WA; south to Mexico. Native. Plants with few seeds per capsule have larger seeds, and thus some specimens might suggest J. capillaris, but there is no overlap. Juncus capillaris always has fewer than 10 seeds per capsule.
Source	Flora of Oregon, volume 1, page 284 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. torreyi, J. triglumis, J. trilocularis, J. uncialis
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

Juncus tiehmii

Tiehm's dwarf rush

Habit

Plants annual, 0.5–6 cm tall, unbranched.

Leaves

capillary;

basal.

Inflorescences

1–4(7) flowers in a terminal cluster;

flowers subtended by 2 bractlets;

tips acute.

Flowers

tepals usually 4, pale green or pink;

stamens 2(3);

filaments 0.6–0.9 mm;

anthers 0.3–0.4 mm;

styles 0.1– 0.3 mm.

Capsules

usually elliptic to oblong, equaling or longer than the tepals, pale green or pink.

Seeds

up to 7 per chamber, 12–30 per capsule, 0.3–0.5 × 0.2–0.3 mm, longitudinally striate (at 10×).

=34.

Juncus tiehmii

Distribution

[BONAP county map]

Discussion

Damp depressions, stream banks, sunny floodplains. 1000– 2000m. BR, ECas. CA, NV, ID, WA; south to Mexico. Native.

Plants with few seeds per capsule have larger seeds, and thus some specimens might suggest J. capillaris, but there is no overlap. Juncus capillaris always has fewer than 10 seeds per capsule.

Source

Flora of Oregon, volume 1, page 284
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. torreyi, J. triglumis, J. trilocularis, J. uncialis

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

Unless otherwise noted, all data comes from OregonFlora.

Choose a data source: Flora of North America, OregonFlora, UW Burke Herbarium

The species comparison tool is brought to you by:

OregonFlora species comparison

Juncus tiehmii

Juncus tiehmii