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inch high dwarf rush, inch-high rush, twelfth rush

Cooper's rush

Habit Herbs, annual, cespitose, 0.8–3.5 cm. Herbs, perennial, robust, tufted, 4–10 dm.
Rhizomes

short.

Culms

to 70, more than 0.2 mm diam..

terete, 1.5–2.5 mm diam.

Cataphylls

several, reddish brown, often apiculate.

Leaves

to 2.2 cm, 1/2–3/4 height of plant.

basal, 1–2;

auricles essentially absent;

blade terete, 10–40 dcm, shorter than culm.

Inflorescences

terminal solitary flowers;

bracts subtending inflorescence 1, widely truncate, enwrapping culm, inconspicuous, 0.25–0.9 mm, membranous, apex widely truncate, completely sheathing culm..

glomerules 3–12, each with (1–)2–5 flowers, open, branches unequal, 3–12 cm, primary bract terete or slightly compressed, shorter to longer than inflorescence.

Flowers

3-merous, : tepals erect to recurved at maturity, greenish or tinged red, 2–4 × 0.6–0.9 mm;

outer and inner series nearly equal, apex acutish;

stamens usually 3, filaments 0.9–1.6 mm, anthers 0.3–0.4 mm, 1/3 length of filaments;

style 0.1–0.3 mm, stigma 0.4–1.3 mm.

tepals straw-colored to pale green, ovate-lanceolate, 4–5 mm, apex acuminate or setaceous;

inner series elliptic, nearly equal, margins wide, scarious, apiculate;

stamens 6, filaments 1 mm, anthers 1.5–2 mm;

style 1 mm.

Capsules

reddish to maroon, 3-locular, ovoid to ellipsoid, 1.8–3.2 × 1–2.5 mm, nearly equal or shorter than the tepals.

tan to light reddish brown, 3-locular, ellipsoid, 3.7–4.5 ×1.6–2 mm, mostly shorter than or nearly equal to perianth.

Seeds

ovoid, 0.3–0.4 mm.

dark amber, obovoid, body 0.7–1 mm, tails 0.1–0.5 mm.

n

= 16.

Juncus uncialis

Juncus cooperi

Phenology Flowering and fruiting spring–early summer. Flowering and fruiting spring–summer.
Habitat Margins of vernal pools and ponds Saline flats and meadows or edges of salt marshes
Elevation 0–1700 m (0–5600 ft) below 600 m (below 2000 ft)
Distribution
from FNA
CA; NV; OR
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ; CA; NV; UT; Mexico
[BONAP county map]
Source FNA vol. 22. FNA vol. 22.
Parent taxa Juncaceae > Juncus > subg. Graminifolii Juncaceae > Juncus > subg. Juncus
Sibling taxa
J. acuminatus, J. acutiflorus, J. acutus, J. alpinoarticulatus, J. anthelatus, J. arcticus, J. articulatus, J. biglumis, J. bolanderi, J. brachycarpus, J. brachycephalus, J. brachyphyllus, J. brevicaudatus, J. bryoides, J. bufonius, J. bulbosus, J. caesariensis, J. canadensis, J. capillaris, J. capitatus, J. castaneus, J. chlorocephalus, J. compressus, J. confusus, J. cooperi, J. coriaceus, J. covillei, J. debilis, J. dichotomus, J. diffusissimus, J. drummondii, J. dubius, J. dudleyi, J. effusus, J. elliottii, J. ensifolius, J. falcatus, J. filiformis, J. filipendulus, J. georgianus, J. gerardii, J. greenei, J. gymnocarpus, J. hallii, J. hemiendytus, J. howellii, J. inflexus, J. interior, J. kelloggii, J. leiospermus, J. lesueurii, J. longistylis, J. luciensis, J. macrandrus, J. macrophyllus, J. marginatus, J. maritimus, J. megacephalus, J. mertensianus, J. militaris, J. nevadensis, J. nodatus, J. nodosus, J. occidentalis, J. orthophyllus, J. oxymeris, J. parryi, J. patens, J. pelocarpus, J. pervetus, J. phaeocephalus, J. polycephalus, J. regelii, J. repens, J. roemerianus, J. scirpoides, J. secundus, J. squarrosus, J. stygius, J. subcaudatus, J. subtilis, J. supiniformis, J. tenuis, J. texanus, J. textilis, J. tiehmii, J. torreyi, J. trifidus, J. triformis, J. triglumis, J. trigonocarpus, J. validus, J. vaseyi, J. xiphioides
J. acuminatus, J. acutiflorus, J. acutus, J. alpinoarticulatus, J. anthelatus, J. arcticus, J. articulatus, J. biglumis, J. bolanderi, J. brachycarpus, J. brachycephalus, J. brachyphyllus, J. brevicaudatus, J. bryoides, J. bufonius, J. bulbosus, J. caesariensis, J. canadensis, J. capillaris, J. capitatus, J. castaneus, J. chlorocephalus, J. compressus, J. confusus, J. coriaceus, J. covillei, J. debilis, J. dichotomus, J. diffusissimus, J. drummondii, J. dubius, J. dudleyi, J. effusus, J. elliottii, J. ensifolius, J. falcatus, J. filiformis, J. filipendulus, J. georgianus, J. gerardii, J. greenei, J. gymnocarpus, J. hallii, J. hemiendytus, J. howellii, J. inflexus, J. interior, J. kelloggii, J. leiospermus, J. lesueurii, J. longistylis, J. luciensis, J. macrandrus, J. macrophyllus, J. marginatus, J. maritimus, J. megacephalus, J. mertensianus, J. militaris, J. nevadensis, J. nodatus, J. nodosus, J. occidentalis, J. orthophyllus, J. oxymeris, J. parryi, J. patens, J. pelocarpus, J. pervetus, J. phaeocephalus, J. polycephalus, J. regelii, J. repens, J. roemerianus, J. scirpoides, J. secundus, J. squarrosus, J. stygius, J. subcaudatus, J. subtilis, J. supiniformis, J. tenuis, J. texanus, J. textilis, J. tiehmii, J. torreyi, J. trifidus, J. triformis, J. triglumis, J. trigonocarpus, J. uncialis, J. validus, J. vaseyi, J. xiphioides
Name authority Greene: Pittonia 2: 105. (1890) Engelmann
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