Flora of North America species comparison

The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links

Juncus tenuis

Juncus debilis

path rush, poverty or slender rush, poverty rush, slender rush

weak rush
Habit Herbs, perennial, tufted, 1.5–5 dm. Herbs, perennial, cespitose, 1–2.5 dm.
Rhizomes

densely branching.

Culms

few–20.

erect, terete, 1–2 mm diam., smooth.
Cataphylls

0–1, maroon or dark green, apex acute.
Leaves

basal, (1–)2–3;

auricles 2–5 mm, apex acute, membranous;

blade flat, 3–12 cm × 0.5–1 mm, margins entire.

basal 0–1, cauline 1–3;

auricles 1–1.5 mm, apex rounded, scarious;

blade maroon or dark green, terete, 1–12.5 cm × 0.5–1.5 mm.
Inflorescences

5–40-flowered, borne congested or branch internodes ca. as long as tepals, ssomewhat loose, 1–5 cm;

primary bract usually longer than inflorescence.

terminal panicles of 3–50 heads, 2–8 cm, branches ascending to spreading;

primary bract erect;

heads 2–10-flowered, obpyramidal, 2–5 mm diam.
Flowers

bracteoles 2;

tepals greenish, lanceolate, 3.3–4.4 mm;

outer and inner series nearly equal;

stamens 6, filaments 0.5–0.9 mm, anthers 0.1–0.2 mm;

style 0.1–0.2 mm.

tepals green to straw-colored, lanceolate, 1.8–2.3(–2.5) mm, apex sharply acuminate;

stamens 3, 1/2 filament length.
Capsules

tan or light brown, 1-locular to pseudo-3-locular, ellipsoid, (3.3–)3.8–4.7 × (1.1–)1.3–1.7 mm, nearly equal to tepals.

exserted, straw-colored, 1-locular, narrowly ellipsoid to lanceoloid, 2.8–3.7 7(–4.2) mm, apex acute, valves separating at dehiscence.
Seeds

tan, ellipsoid to lunate, (0.52–)5.5–0.65(–0.7) mm, not tailed.

ellipsoid, 0.3–0.4 mm, not tailed;

body clear yellow-brown.
2n

= 80.

Juncus tenuis

Juncus debilis
Phenology Flowering spring–early summer. Fruiting summer.
Habitat Exposed or shaded sites in soils ranging from sandy to clayey under moist or drier conditions, oftentimes these sites naturally or otherwise disturbed (e.g., game or human trails) Marshy shores, in small streams, swamps, wet clearings, spring runs, commonly in very soft mucky substrates
Elevation 0–700 m (0–2300 ft)
Distribution
from FNA
AK; AL; AR; AZ; CA; CO; CT; DC; DE; FL; GA; IA; ID; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; MT; NC; ND; NE; NH; NJ; NM; NV; NY; OH; OK; OR; PA; RI; SC; SD; TN; TX; UT; VA; VT; WA; WI; WV; WY; AB; BC; MB; NB; NS; ON; PE; QC; SK [Introduced worldwide]
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; AR; DE; FL; GA; IL; KY; LA; MD; MO; MS; NC; NJ; NY; PA; SC; TN; TX; VA; Mexicos (Chiapas); Central America (Honduras)
[WildflowerSearch map]
[BONAP county map]
Discussion

Juncus tenuis occurs throughout North America. It is particularly abundant in northeastern United States and eastern Canada, although infrequent in the south and west.

Through the use of isozyme electrophoresis, hybridization can be demonstrated between various members of the Juncus tenuis complex, including Juncus tenuis, J. anthelatus, J. interior, J. secundus, and J. dichotomus (R. E. Brooks, unpubl.). Juncus ××oronensis is thought to be a hybrid between J. tenuis and J. vaseyi in the northeast.

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

Juncus debilis A. Gray is a name being proposed for conservation.

(Discussion copyrighted by Flora of North America; reprinted with permission.)
Source FNA vol. 22. FNA vol. 22.
Parent taxa Juncaceae > Juncus > subg. Poiophylli Juncaceae > Juncus > subg. Septati
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. 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. covillei, 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
Synonyms J. bicornis, J. bicornis var. williamsii, J. macer, J. macer, J. macer var. williamsii, J. tenuis var. bicornis, J. tenuis var. multicornis, J. tenuis var. williamsii J. acuminatus var. debilis, J. radicans
Name authority Willdenow: Sp. Pl. 2(1): 214. (1799) A. Gray: Manual 481506. (1848)
Web links 
Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).



Type/paste one or more Latin names into the boxes above; matching taxa will show up below the box as you type. You can use the up/down arrow keys to move through the list.

(If the plant you're looking for doesn't show up in the auto-complete list, that means it either isn't described in Flora of North America yet, or it's listed under a synonym. And please note that Flora of North America is still missing several plant families, including Apiaceae, Boraginaceae, and Polemoniaceae.)

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

The species comparison tool is brought to you by:
Northwest Wildflowers