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Juncus mexicanus
MEXICAN RUSH

Higher Taxonomy
Family: JuncaceaeView DescriptionDichotomous Key

Common Name: RUSH FAMILY
Habit: Annual, perennial herb generally from rhizomes. Stem: round or flat. Leaf: generally basal; sheath margins fused, or overlapping and generally with 2 ear-like extensions at blade junction; blade round, flat, or vestigial, glabrous or margin hairy. Inflorescence: head-like clusters or flowers 1, variously arranged; bracts subtending inflorescence 2, generally leaf-like; bracts subtending inflorescence branches 1--2, reduced; bractlets subtending flowers generally 1--2, generally translucent. Flower: generally bisexual, radial; sepals and petals similar, persistent, scale-like, green to brown or +- purple-black; stamens generally 3 or 6, anthers linear, persistent; pistil 1, ovary superior, chambers generally 1 or 3, placentas 1 and basal or 3 and axile or parietal, stigmas generally > style. Fruit: capsule, loculicidal. Seed: 3--many, generally with white appendages on 1 or both ends.
Genera In Family: 7 genera, 440 species: temperate, arctic, and tropical mountains. Note: Flowers late spring to early fall.
eFlora Treatment Author: Peter F. Zika, except as noted
Scientific Editor: Douglas H. Goldman, Bruce G. Baldwin.
Genus: JuncusView DescriptionDichotomous Key

Common Name: RUSH
Habit: Rhizome 0 or generally with scale-like leaves. Stem: generally cylindric or flat. Leaf: blade well developed and cylindric or flat, occasionally closely resembling stem, or reduced to small point; crosswalls generally present; appendages generally present at blade-sheath junction. Inflorescence: generally terminal, appearing lateral when pushed aside by inflorescence bract; bractlets 0--2. Flower: sepals, petals similar; stamens generally 3 or 6(2); pistil 1, ovary chambers 1--3, placentas axile or parietal, stigmas generally 3(2). Seed: many.
Species In Genus: 315 species: worldwide, especially northern hemisphere. Etymology: (Latin: to join or bind, from use of stems) Note: All species with leaf crosswalls may have leaves, stems swollen, deformed by sucking insects. Fruiting time given instead of flowering time. Plants included in TJM2 as Juncus brachyphyllus now treated in California as a new species, Juncus trilocularis (Zika 2012 Rhodora 114:309--329); Juncus bulbosus, Juncus dichotomus, and Juncus elliottii, only noted as naturalized in TJM2, now fully treated.

Juncus mexicanus Willd.
NATIVE
Habit: Perennial herb 10--60 cm; rhizome heavy. Stem: erect or generally spirally twisted, flattened, slender. Leaf: basal; sheaths loose, appendages short, firm; some upper sheaths generally bearing 5--20 cm blades resembling stem. Inflorescence: appearing lateral, +- compact; lowest bract 1--25 cm, cylindric, resembling stem; flowers 2--many. Flower: perianth parts 3--5.5 mm, sepals > petals, generally acuminate, color variable, midstripe intensity and width variable, margins generally scarious; stamens 6, filaments << anthers. Fruit: generally >= perianth, ovoid, 3-angled; beak 0.3 mm. Seed: 0.5--0.7 mm; appendages 0.
Ecology: Common. Coast to montane meadows; Elevation: < 3800 m. Bioregional Distribution: CA; Distribution Outside California: to southern Oregon, New Mexico, Central America, South America. Fruiting Time: Aug--Nov Note: Sheath blades less common farther n.
Synonyms: Juncus arcticus Willd. var. mexicanus (Willd.) Balslev
eFlora Treatment Author: Peter F. Zika
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Citation for this treatment: Peter F. Zika 2016. Juncus mexicanus, in Jepson Flora Project (eds.) Jepson eFlora, http://ucjeps.berkeley.edu/cgi-bin/get_IJM.pl?tid=29687, accessed on December 04, 2016.

Citation for the whole project: Jepson Flora Project (eds.) 2016. Jepson eFlora, http://ucjeps.berkeley.edu/IJM.html, accessed on December 04, 2016.


Juncus mexicanus
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© 2002 Larry Blakely
Juncus mexicanus
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© 2004 Steve Matson
Juncus mexicanus
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© 2004 Steve Matson
Juncus mexicanus
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© 2004 Steve Matson
Juncus mexicanus
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© 2016 Neal Kramer
Juncus mexicanus
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© 2002 Larry Blakely

More photos of Juncus mexicanus in CalPhotos


Geographic subdivisions for Juncus mexicanus:
CA;
Markers link to CCH specimen records. Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues. Purple markers indicate specimens collected from a garden, greenhouse, or other non-wild location.
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map of distribution 1
(Note: any qualifiers in the taxon distribution description, such as 'northern', 'southern', 'adjacent' etc., are not reflected in the map above, and in some cases indication of a taxon in a subdivision is based on a single collection or author-verified occurence).

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Data provided by the participants of the Consortium of California Herbaria.
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CCH collections by month

Duplicates counted once; synonyms included.
Species do not include records of infraspecific taxa.
Blue line denotes eFlora flowering time.