Juncaceae

Taxonomy

Family name: Juncaceae A.L. Jussieu

Synonym(s): [none]

Common name(s): rush family

*Number of genera/species: 8/464

List of genera records in GRIN-Global

Disseminule

fruit or seed

Description

Fruit dehiscent, loculicidalloculicidal:
type of capsular dehiscence, opening longitudinally through the locules (compare septicidal)
capsulecapsule:
a dry, dehiscent fruit formed by two or more carpels
, rarely a circumscissilecircumscissile:
(~pyxis); type of capsular dehiscence, opens by a lid (splitting transversely)
capsulecapsule:
a dry, dehiscent fruit formed by two or more carpels
(Distichia and Patosia), or indehiscentindehiscent:
not opening on its own, as in a fruit
(Oxychloe), 2–9 mm long, globoseglobose:
3D shape—more or less spherical
to trigonoustrigonous:
3D shape—having three faces that meet at distinct angles; triangular in outline
, tereteterete:
approximately circular in cross section; width and thickness approximately equal
or angledangled:
2D shape—having sides that meet at acute or obtuse angles  
in transectiontransection:
a cross section; representing a plane made by cutting across an organ at a right angle to its length
, sometimes beakedbeaked:
a usually firm, terminal appendage, sometimes tapered
or with stylar remnantsstylar remnants:
remnant of a style
, many seeded except three-seeded in Luzula. Pericarppericarp:
fruit wall or fruit coat
black, brown, purple, red, orange, shinyshiny:
uniformly reflecting a high proportion of incident light at all angles
or dulldull:
reflecting only a low proportion of incident light, with no apparent sheen
, chartaceouschartaceous:
=papery, papyraceous
or indurateindurate:
texture—hardened or stony; yielding under strong pressure; not deformable without internal structural disruption
, smooth.

Seed globoseglobose:
3D shape—more or less spherical
to irregular, tereteterete:
approximately circular in cross section; width and thickness approximately equal
in transectiontransection:
a cross section; representing a plane made by cutting across an organ at a right angle to its length
, 0.3–4 mm long, sometimes with winglike beakbeak:
a usually firm, terminal appendage, sometimes tapered
or caudatecaudate:
tapering to a long, tail-like appendage
appendage, and often with conspicuous raphes. Seeds in Luzula shinyshiny:
uniformly reflecting a high proportion of incident light at all angles
and with basalbasal:
at or pertaining to the point of attachment; (of embryo) embryo occupies one end of the seed
or apicalapical:
at or pertaining to the end of the seed or fruit distal from its point of attachment (i.e., base)
elaiosomes. Seed coat brown, yellow, red, or white, dulldull:
reflecting only a low proportion of incident light, with no apparent sheen
or shinyshiny:
uniformly reflecting a high proportion of incident light at all angles
, membranousmembranous:
texture—extremely thin, pliable, and fairly tough
, loose or tight, smooth, reticulatereticulate:
surface relief—netted, raised walls or concave grooves forming a net-like surface pattern with flat, concave, or convex interspaces
, wrinkledwrinkled:
surface relief—shallow, irregular folds and furrows covering the surface; appearing overall though crumpled and then spread out
, or striatestriate:
surface relief—having fine, parallel lines, grooves or ridges
. In some species of Juncus and Luzula elegans, seed coat may be mucilaginousmucilaginous:
resembling mucilage; moist and sticky
when wet.

Embryo rudimentaryrudimentary:
(of embryo) embryo is small and fills less than a quarter of the seed and can be variable in shapes, such as linear, spatulate, or oval
and minute or well developed and larger, linearlinear:
(shape) long, narrow, and uniform in width; (of embryo) embryo is straight and much longer than wide
or broad, straight, axileaxile:
on or of the axis
and centric or peripheralperipheral:
(of embryo) embryo is curved around the outer edge of the seed, near the seed coat
. Endospermendosperm:
nutritive starch- and oil-containing tissue present in many seeds
copious, fleshyfleshy:
texture—fairly firm and dense, juicy or at least moist, and easily cut
, firmfirm:
texture—yielding under only moderately strong pressure; only slightly deformable without internal structural disruption
.

Identification features

Fruit
Type	capsule, rarely nutlet
Size range	2–9 mm long
Shape(s)	globose, oblongoblong: 2D shape—much longer than broad with nearly parallel sides, corners are rounded , ellipsoidellipsoid: 3D shape—elliptic , trigonoustrigonous: 3D shape—having three faces that meet at distinct angles; triangular in outline , conical
Texture	chartaceous, indurate
Surface relief	smooth
Color(s)	brown, purple, red, orange, black
Unique features	Small, smooth capsulescapsules: a dry, dehiscent fruit formed by two or more carpels often with many beakedbeaked: a usually firm, terminal appendage, sometimes tapered or caudatecaudate: tapering to a long, tail-like appendage appendaged seeds.
Seed
Size range	0.3–4 mm long
Shape(s)	polygonal, globoseglobose: 3D shape—more or less spherical , ovoidovoid: 3D shape—ovate , sectoroidsectoroid: 3D shape—a wedge-shaped slice taken from an ovoid or globose structure (2D shape, sector-shaped) , ellipsoidellipsoid: 3D shape—elliptic , fusiformfusiform: spindle-shaped; broadest at the middle and tapering at both ends , irregular, oblong
Surface relief	smooth, reticulatereticulate: surface relief—netted, raised walls or concave grooves forming a net-like surface pattern with flat, concave, or convex interspaces , wrinkledwrinkled: surface relief—shallow, irregular folds and furrows covering the surface; appearing overall though crumpled and then spread out , striate
Color(s)	brown, red, yellow, white
Unique features	Seeds often beakedbeaked: a usually firm, terminal appendage, sometimes tapered , with caudatecaudate: tapering to a long, tail-like appendage appendage, and/or with conspicuous rapheraphe: a ridge or seam on the seed coat, formed by the portion of the funiculus united to the ovule wall in longitudinally curved ovules . Seed coats may be mucilaginousmucilaginous: resembling mucilage; moist and sticky .
Other
Embryo	rudimentary rudimentary: (of embryo) embryo is small and fills less than a quarter of the seed and can be variable in shapes, such as linear, spatulate, or oval and minute or well developed and larger, linearlinear: (shape) long, narrow, and uniform in width; (of embryo) embryo is straight and much longer than wide or broad, straight, axileaxile: on or of the axis and centric or peripheral
Nutritive tissuenutritive tissue: tissue within the seeds that nourishes the developing embryo; such as endosperm, perisperm, or chalazosperm in angiosperms; megagametophyte in gymnosperms	endosperm endosperm: nutritive starch- and oil-containing tissue present in many seeds copious, fleshyfleshy: texture—fairly firm and dense, juicy or at least moist, and easily cut , firm

Distribution

Worldwide.

Distribution map courtesy of Angiosperm Phylogeny Website.

References

Baskin and Baskin 2021Baskin and Baskin 2021:
Baskin C and Baskin J. 2021. Relationship of the lateral embryo (in grasses) to other monocot embryos: A status up-grade. Seed Science Research 31 (3): 199-210. doi:10.1017/S0960258521000209; Dahlgren et al. 1985Dahlgren et al. 1985:
Dahlgren RMT, Clifford HT, and Yeo PF. 1985. The families of the monocotyledons: structure, evolution, and taxonomy. Springer-Verlag, Berlin. 520 pp.; Flora of North America Editorial Committee 1993+Flora of North America Editorial Committee 1993+:
Flora of North America Editorial Committee, eds. 1993+. Flora of North America North of Mexico [Online]. 22+ vols. Flora of North America Association, New York and Oxford. Accessed January-December 2021. URL: http://beta.floranorthamerica.org.; Kirkbride et al. 2006Kirkbride et al. 2006:
Kirkbride JH, Jr, Gunn CR, and Dallwitz MJ. 2006. Family guide for fruits and seeds, vers. 1.0. Accessed September 2020ndash;January 2022. URL: https://nt.ars-grin.gov/seedsfruits/keys/frsdfam/index.cfm .; Kubitzki et al. 1990+Kubitzki et al. 1990+:
Kubitzki K et al., eds. 1990+. The families and genera of vascular plants. 7+ vols. Berlin etc.; Stevenson and Loconte 1995Stevenson and Loconte 1995:
Stevenson DW and Loconte H. 1995. A cladistic analysis of monocot families. In: Rudall PJ, Cribb PJ, Cutler DF, and Humphries CJ, eds. Monocotyledons: Systematics and Evolution. Royal Botanic Gardens, Kew.; Watson and Dallwitz 1992+Watson and Dallwitz 1992+:
Watson L and Dallwitz MJ. 1992+. The families of flowering plants: descriptions, illustrations, identification, and information retrieval. Version: 6th Accessed September 2020-September 2022. URL: delta-intkey.com; Zhengyi et al. 2004+Zhengyi et al. 2004+:
Zhengyi W, Raven PH, and Deyuan H. 2004+. Flora of China [online]. 25 vols. Science Press, Beijing China amp; Missouri Botanical Garden, St. Louis USA. Accessed January-December 2021. http://flora.huh.harvard.edu/china/

*The number of genera and species is based on Christenhusz and Byng 2016Christenhusz and Byng 2016:
Christenhusz MJM and Byng JW. 2016. The number of known plant species in the world and its annual increase. Phytotaxa 261 (3): 201ndash;217. https://doi.org/10.11646/phytotaxa.261.3.1, which may differ from the number of genera in GRIN-Global.