Juncus
From Natural History of Southeast Alaska
| Scientific name is | PlantDescription | StemDescription | LeafDescription | InflorescenceDescription | FlowerDescription | CapsuleDescription | SeedDescription | |
|---|---|---|---|---|---|---|---|---|
| Juncus alpinoarticulatus | Juncus alpinoarticulatus | perennial, rhizomatous, 0.5--5 dm. Rhizomes 2--4 mm diam., not swollen. | Culms erect, terete, 1--3 mm diam., smooth. Cataphylls 0--1, straw-colored or maroon, apex acute | basal 0--2, cauline 1--2(--5); auricles 0.5--1.2 mm, apex rounded, scarious; blade green to straw-colored, terete, 1.5--12 cm x 0.5--1.1 mm | terminal panicles of 5--25 heads, 3--11 cm, branches erect to ascending; primary bract erect; heads 2--10-flowered, obpyramidal, usually with some flowers short- pedicellateled, 2--6 mm in diam | tepals greenish to straw-colored, lanceolate to oblong; outer tepals 1.8--3 mm, apex obtuse, mucronate; inner tepals 1.6--2.7 mm, apex obtuse; stamens 6, anthers 1/2 filament length. | equaling perianth to usually exserted, chestnut brown to straw-colored, imperfectly 3-locular, oblong to oblong-ovoid, 2.3--3.5 mm, apex obtuse, valves separating at dehiscence | oblong to ovoid, 0.5--0.7 mm, not tailed |
| Juncus arcticus | Juncus arcticus | perennial, 2--10 dm. Rhizomes long- creeping | Culms erect, 1--3 mm diam. Cataphylls several | blade usually absent | lateral, 3--many-flowered, loose to congested; primary bract barely exceeding to many times longer than inflorescence. | bracteoles membranous; tepals chestnut brown or paler, lanceolate, (2.5--)3.3--5.5(--6) mm, margins clear; inner series loosely subtending capsule at maturity; usually slightly shorter, margins scarious to clear, apex acutish to obtuse; stamens 6, filaments 0.2--1.1 mm, anthers 0.9--2.2 mm; style 0.9--1.5 mm. | 3-locular or infrequently pseudo-3-locular, oblate to narrowly ovoid, 3.5--4(--4.5) mm, equal to or exceeding perianth. | dark amber, oblate to ellipsoid, 0.6--0.8 mm. |
| Juncus articulatus | Juncus articulatus | perennial, rhizomatous to nearly cespitose, 0.5--6(--10) dm | Culms erect to decumbent (and floating), terete, 1--3 mm diam., smooth. Cataphylls 1, maroon to straw-colored, apex acute to obtuse. | basal 0--2, cauline (1--)3--6; auricles 0.5--1 mm, apex rounded, scarious; blade green to straw-colored, terete, 3.5--12 cm x 0.5--1.1 mm | terminal panicles of 3--30(--50) heads, 3.5--8 cm, branches spreading; primary bract erect; heads 3--10-flowered, obpyramidal to hemispheric, 6--8 mm diam | tepals green to straw-colored or dark brown, ovate to lanceolate, 1.8--3 mm; outer tepals with apex acute or acuminate; inner tepals with apex acute acuminate to obtuse; stamens 6, anthers equal to filament length. | Capsules exserted ca. 1 mm beyond perianth, chestnut brown to dark brown, imperfectly 3-locular, ellipsoid or ovoid, 2.8--4 mm, apex acute proximal to beak, valves separating at dehiscence. | Seeds obovoid, 0.5 mm, not tailed |
| Juncus biglumis | Juncus biglumis | perennial,loosely cespitose, 0.25--1.6 dm. | nearly terete. Cataphylls 2--4 | basal, 1--4; sheaths loose; auricles absent or rounded, 0.5 mm; blade imperfectly septate, ascending, roundish in cross section | heads, 1--2(--4)-flowered; primary bracts much longer than inflorescence. | tepals brown to blackish, oblong, 2.5--4 mm, apex obtuse; outer and inner series nearly equal; stamens 6, filaments 1--1.5 mm, anthers 0.5--0.7 mm; style deciduous, 0.3--0.4 mm. | Capsules pale with dark purplish valve margins, pseudo-3-locular, oblate to narrowly ovoid, 4--5.5 x 1.7--2.3 mm, exceeding perianth, apex retuse | yellowish tan, fusiform-ovoid, 0.7--0.9 mm, short tailed. |
| Juncus bufonius | Juncus bufonius | annual, cespitose, 0.5--4 dm. | 1--many, occasionally becoming decumbent. Cataphylls 0--2. | basal and cauline; auricles rudimentary or absent; blade flat, 3--13 cm x 0.3--1.1 mm. | loose and diffuse or less often compact, usually at least ½1/2 total height of plant; primary bract shorter than inflorescence. | bracteoles 2; tepals greenish, lanceolate, 3.8--7(--8.5) mm; inner series slightly shorter, apex sometimes obtuse; stamens 3--6, filaments (0.7--)1--1.8 mm, anthers 0.3--0.8 mm; style 0.1--0.2 mm. | tan to reddish brown, 3-locular, ellipsoid to narrowly so, slightly truncate, 2.7--4 x 1--1.5 mm, sometimes exceeding inner tepals but usually not outer series. | yellowish, widely ellipsoid to ovoid, 0.26--0.49, not tailed. |
| Juncus castaneus | Juncus castaneus | perennial, strongly rhizomatous, 1--4 dm. | solitary, 1--2 mm diam. Cataphylls 1--2. | partially cauline, 3--5, auricles absent distally, rounded proximally; blade channeled, to 20 cm, reduced distally | glomerules, 1--3(--5), each with 2--10 flowers; peduncles 0.4--1.5 cm; primary bracts somewhat inflated, usually surpassing inflorescence. | bracteoles absent; tepals brown or occasionally paler, lanceolate, 4.5--6.6 mm, apex acute to obtuse; inner series slightly shorter; stamens 6, filaments 2.5--3.5 mm, anthers 0.6--1.3 mm; style 1--1.3 mm. | chestnut brown, 3-locular, narrowly oblong, 6.5--8.5 x 1.8--2.3 mm | pale yellow, fusiform, body 0.6--0.7 mm, tails 0.8--1.1 mm |
| Juncus covillei | Juncus covillei | annual, cespitose, 0.5--4 dm. | 1--many, occasionally becoming decumbent. Cataphylls 0--2. | basal and cauline; auricles rudimentary or absent; blade flat, 3--13 cm x 0.3--1.1 mm. | loose and diffuse or less often compact, usually at least ½1/2 total height of plant; primary bract shorter than inflorescence. | bracteoles 2; tepals greenish, lanceolate, 3.8--7(--8.5) mm; inner series slightly shorter, apex sometimes obtuse; stamens 3--6, filaments (0.7--)1--1.8 mm, anthers 0.3--0.8 mm; style 0.1--0.2 mm. | tan to reddish brown, 3-locular, ellipsoid to narrowly so, slightly truncate, 2.7--4 x 1--1.5 mm, sometimes exceeding inner tepals but usually not outer series. | yellowish, widely ellipsoid to ovoid, 0.26--0.49, not tailed. |
| Juncus drummondii | Juncus drummondii | perennial, strongly tufted, to 4 dm. Rhizomes densely short-branched. | Culms terete. Cataphylls several. | blade absent or rarely present, to 1 cm. | 2--5-flowered, loosely compact; primary bract usually longer than inflorescence. | tepals brown to chestnut brown with green midstripe, lanceolate or widely so, (4--)5--8 mm, margins clear; inner series loosely subtending capsule at maturity, shorter; stamens 6, filaments 0.7--1 mm, anthers 1.1--1.6 mm; style 0.2 mm. | brown to chestnut brown, 3-locular, oblate, 4.5--7(--8) x 1.8--2.2 mm, nearly equal to or exceeding perianth | amber, body oblate, 0.5--0.6 mm |
| Juncus dudleyi | Juncus dudleyi | perennial, 2--10 dm. Rhizomes densely branching. | 1--20. Cataphylls 1--3 | basal, 2--3; auricles yellowish, 0.2--0.4 mm, leathery; blade flat, 5--30 cm x 0.5--1 mm, margins entire, turned up, occasionally involute | compact and few flowered to loose and lax with to 80 flowers, 1.5--5(--9) cm; primary bract usually exceeding inflorescence. | bracteoles 2; tepals greenish, lanceolate, 4--5 mm; inner series nearly equal, spreading in fruit, nearly equal to or exceeding capsule; stamens 6, filaments 0.8--1.2 mm, anthers 0.6--1 mm; style 0.2 mm. | tan, 1-locular to pseudo-3-locular, ellipsoid, 2.9--3.6 x 1.5--1.9 mm | tan to amber, ellipsoid to lunate, 0.4--0.67 mm, not tailed |
| Juncus effusus | Juncus effusus | perennial, 4--13 dm. Rhizomes short -branched, forming distinct, often large clumps | Culms erect, terete, 1--2.5 mm diam. at top of sheaths. Cataphylls several. | blade absent | lateral, compound dichasia, many flowered; primary bract erect, terete, extending well beyond dichasium. | tepals tan or darker, usually with greenish midstripe, lanceolate, 1.9--3.5 mm; inner slightly shorter; stamens 3, filaments 0.5--0.8 mm, anthers 0.5--0.8 mm; style 0.2 mm | greenish tan or darker, 3-locular, broadly ellipsoid to oblate, 1.5--3.2 mm. | amber, (0.3--)0.4---0.5 mm |
| Juncus ensifolius | Juncus ensifolius | perennial, rhizomatous, 2--6 dm. Rhizomes 2--3 mm diam | Culms erect, 2--6 mm diam. Cataphylls 0 or 1--2, straw-colored, apex narrowly acute | basal 1--3, cauline 2--6, straw-colored; auricles absent; blade 2--25 cdm x 1.5--6 mm | panicles or racemes of 2--50 heads or heads solitary, 2--14 cm, erect or ascending branches; primary bract erect; heads 3--70-flowered, obovoid to globose, 7--11 mm diam | tepals green to brown or reddish brown, lanceolate; outer tepals 2.7--3.6(--4) mm, apex acuminate; inner tepals 2.2--3(--3.5) mm, nearly equal, apex acuminate; stamens 3 or 6; anthers ½1/2 to equal filament length | included to slightly exserted, chestnut to dark brown, 1-locular, oblong, 2.4--4.3 mm, apex obtuse proximal to beak. | elliptic to obovate, 0.4--1 mm, occasionally tailed |
| Juncus falcatus | Juncus falcatus | perennial, rhizomatous, 0.5--3 dm | erect, slightly compressed | basal 2--4, cauline 1--3; auricles absent or rudimentary; blade flat, 4--15 cm x 1.5--3 mm | glomerules, (1--)2--5, each with 2--15 flowers, open or aggregate; primary bract usually exceeding inflorescence | tepals brown, ovate-lanceolate, 4.5--6 mm, margins scarious, minutely papillate; inner series slightly shorter | brown, 3-locular, obovoid, 3--5 mm, shorter than perianth | ovoid to pyriform, 0.7 mm, not tailed |
| Juncus filiformis | Juncus filiformis | perennial, 0.2--3.5 dm. Rhizomes widely creeping, sparingly branched, 1.5--2 mm diam., nodes closely set. | terete, 1 mm diam. Cataphylls several | blade absent. | 3--10(--12)-flowered, loosely congested, 1--2 cm; primary bract terete, nearly equaling to much longer than culm several flowers in cluster, seemingly from side of stem | pedicellate; bracteoles broadly ovate, tepals light brown or green, lanceolate, 2.5--4.2 mm; inner series loosely subtending capsule at maturity, slightly shorter, margins scarious; stamens 6, filaments 0.5--0.9 mm, anthers 0.5--0.7 mm; style 0.2 mm | tan, 3-locular, nearly globose, 2.5--3 x 1.8--2.1 mm, shorter than perianth | amber, 0.5--0.6 mm, not tailed |
| Juncus mertensianus | Juncus mertensianus | perennial, rhizomatous to cespitose, 0.5--4 dm. Rhizomes 1--2 mm diam., not swollen | Culms erect, terete, 1--3 mm diam., smooth. Cataphylls 0--1, straw-colored to chestnut brown, apex acute | basal 1--2, cauline 0--1; auricles 1--1.2 mm, apex rounded to acute, membranaceous or scarious; blade green to straw-colored, terete, 3--15 cm x 0.3--0.6 mm | terminal single head (rarely cluster of 2 heads), 0.5--1.6 cm; primary bract erect; heads 12--60-flowered, spheric (to hemispheric), 4.5--15 mm diam. | tepals dark purplish brown to black, lanceolate to lance-ovate, apex acute, mucro subulate; outer tepals 2.4--4.9 mm; inner tepals 2.3--4.3 mm; stamens 6, anthers 1/4 to equal filament length | included or slightly exserted, chestnut brown, 1-locular, obovoid, 1.9--3.5 mm, apex obtuse or rounded, valves separating at dehiscence, fertile throughout or only proximal to middle | ellipsoid, 0.4--0.5 mm, not tailed; body clear yellow-brown |
| Juncus nodosus | Juncus nodosus | perennial, rhizomatous, 0.4--5.5(--7) dm. Rhizomes with swollen nodes, 1 mm diam | Culms erect, terete, 1--3 mm diam., smooth. Cataphylls 0 or 1--2., pink to gray, apex acute. | basal 1, cauline 2--4, green to pink; auricles 0.5--1.7 mm, apex rounded, membranaceous to cartilaginous; blade terete, 6--30 cm x 0.5--1.5 mm | terminal racemes of 3--15 heads, 0.6--6 cm, branches ascending to erect; primary bract erect; heads 6--30-flowered, spheric, 6--10(--12) mm diam | tepals green to light brown, lance-subulate, 2.4--4.1 mm, nearly equal, apex acuminate; stamens 3 or 6, anthers 1/2 to equal filament length | exserted, chestnut brown, 1-locular, lance-subulate, 3.2--5 mm, apex tapering, valves separating at dehiscence, fertile throughout or only proximal to middle | oblong, ellipsoid, or obovoid, 0.4--0.5 mm, not tailed |
| Juncus stygius | Juncus stygius | perennial, loosely cespitose, 2--4 dm. | basal 1--3, cauline 1--2; auricles rounded, scarcely prolonged, scarious; blade imperfectly septate (often inconspicuous), ascending, terete to slightly flattened, 8--18 cm x 0.5--1 mm, much reduced distally. | glomerules, 1--3, each with 1--3 flowers; peduncles 0.2--1 cm, primary bracts nearly equal to or slightly surpassing glomerules. | bracteoles absent; tepals pale to reddish brown, lanceolate to lanceolate-ovate, 4--5 mm x 1 mm, apex acutish; outer and inner series nearly equal; stamens 6, filaments 2.5--3.5 mm, anthers 0.4--0.5 mm; style 1--1.2 mm | greenish to tan, pseudo-3-locular, ellipsoid, 5.5--9 x 1.8--2.6 mm | pale yellow, fusiform, body 0.8--1.1 mm, tails 1--1.4 mm. | |
| Juncus supiniformis | Juncus supiniformis | perennial, cespitose or matted, often decumbent, rooting at proximal nodes or floating, 0.3--5 dm | erect, decumbent and rooting at nodes, or floating, terete, 1--2 mm diam., smooth. Cataphylls 0 or 1--2, straw-colored, apex acute. | basal 1--3, cauline 1--4; auricles 0.8--2.1 mm, apex rounded to acute, membranaceous; blade terete, 3.7--15 cm x 0.4--1.3 mm, occasionally with filiform, flaccid, and floating leaves to 60 cm | terminal racemes of 2--9 heads, 2--10 cm, branches erect; primary bract erect; heads 2--12-flowered, obconic or rarely hemispheric, 4--13 mm diam. | tepals light brown or greenish to reddish brown, linear to narrowly lanceolate, apex acute to acuminate-subulate; outer tepals (2.1--)2.8--4.9 mm; inner tepals (2.1--)2.8--5.5 mm; stamens 3 or 6, anthers 1/2--3/4 filament length. | usually exserted, dark brown, 1-locular, ovoid to oblong, (3.2--)3.5--6.1 mm, apex acute to acuminate proximal to beak, valves separating at dehiscence | narrowly obovoid to obovoid, 0.6--0.7 mm, not tailed; body clear yellow-brown |
| Juncus tenuis | Juncus tenuis | perennial, tufted, 1.5--5 dm. Rhizomes densely branching | few--20. | basal, (1--)2--3; auricles 2--5 mm, apex acute, membranous; blade flat, 3--12 cm x 0.5--1 mm, margins entire. | 5--40-flowered, borne congested or branch internodes ca. as long as tepals, ssomewhat loose, 1--5 cm; primary bract usually longer than inflorescence | 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 | tan or light brown, 1-locular to pseudo-3-locular, ellipsoid, (3.3--)3.8--4.7 x (1.1--)1.3--1.7 mm, nearly equal to tepals. | tan, ellipsoid to lunate, (0.52--)5.5--0.65(--0.7) mm, not tailed |
| Juncus triglumis | Juncus triglumis | perennial, cespitose, 0.3--3.5 dm | 1--8, 0.3--0.5 mm diam. Cataphylls 1--2 | basal, 2--4; auricles slightly prolonged, rounded, scarious to ± leathery; blade deeply channeled, 2--10 cm, mostly shorter than culms | solitary heads, each with 2--3(--50) flowers; primary bracts brownish, nearly equal to or slightly shorter than about equaling inflorescence. | tepals pale brown or darker, oblong-lanceolate, 3--5 mm, outer and inner series nearly equal; stamens 6, filaments 2.5--4 mm, anthers 0.6--1 mm; styles 0.5--0.8 mm | tan, pseudo-3-locular, 3-gonous--cylindric, apex obtuse, mucronate | tan or darker, fusiform, body 0.5--1 mm, tails 0.6--1 mm |
