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green head rush

Coville's rush

Habit Herbs, perennial, cespitose, 2–4.5 dm. Herbs, perennial, strongly rhizomatous, 0.5–2.5 dm.
Culms

erect, terete, 1–3 mm diam., smooth.

erect, slightly flattened.

Cataphylls

1, straw-colored or maroon, apex acute.

Leaves

basal 1–2, cauline 2–3;

auricles 2–3.5 mm, apex rounded, scarious;

blade terete, 2–16 cm × 1–2 mm.

basal 2–5, cauline 2–4;

auricles absent or, if present, 0.5–1.5 mm, apex acute;

blade flat, 5–15 cm × 2–3 mm.

Inflorescences

single heads (rarely cluster of 2–3 heads), 0.5–2 cm;

primary bract erect;

heads 15–25-flowered, spheric, 11–14 mm diam.

glomerules, 1–6, each with 3–7 flowers, open to aggregate, 2–6 cm;

primary bract or distal leaves usually exceeding inflorescences.

Flowers

tepals light green to light pink or white, lanceolate, 3.1–4.2 mm, apex obtuse;

stamens 6, anthers 2–3 times filament length.

tepals usually brown, ovate-oblong, 3–4 mm, margins scarious;

inner series slightly shorter, minutely papillate;

stamens 6, filaments 0.8–1.4 mm, anthers 0.8–1.4 mm;

style 1 mm.

Capsules

included, straw-colored, 1-locular, broadly obovoid to ovoid, 2.2–2.5 mm, apex obtuse, valves separating at dehiscence, fertile throughout or only proximal to middle.

3-locular, narrowly ovoid, 4–5 mm.

Seeds

oblong, 0.5 mm, not tailed;

body clear yellow-brown.

narrowly ovoid, 0.3 mm, not tailed.

Juncus chlorocephalus

Juncus covillei

Phenology Fruiting mid summer–fall.
Habitat Sandbars, meadows, damp soil in rock outcrops, and talus
Elevation 1400–3000 m (4600–9800 ft)
Distribution
from FNA
CA; NV
[WildflowerSearch map]
[BONAP county map]
from FNA
CA; ID; MT; OR; WA; BC; Coastal to montane areas
[WildflowerSearch map]
[BONAP county map]
Discussion

Varieties 2 (2 in the flora).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Key
1. Perianth dark brown, apex of inner series rounded; capsule dark brown, 1 mm longer than perianth
var. covillei
1. Perianth pale brown, apex of inner series acute to obtuse; capsule pale brown, barely exceeding perianth
var. obtusatus
Source FNA vol. 22. FNA vol. 22.
Parent taxa Juncaceae > Juncus > subg. Septati Juncaceae > Juncus > subg. Graminifolii
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. 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. uncialis, 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. cooperi, J. coriaceus, 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
Subordinate taxa
J. covillei var. covillei, J. covillei var. obtusatus
Synonyms J. falcatus var. paniculatus
Name authority Engelmann Piper: Contributions from the U. S. National Herbarium 11: 182. (1906)
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