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Vascular Plants of California
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Mentzelia involucrata

Higher Taxonomy
Family: LoasaceaeView DescriptionDichotomous Key
Habit: Annual to subshrub; hairs needle-like, barbed, occasionally stinging. Leaf: alternate [opposite], generally +- pinnate-lobed; stipules 0. Inflorescence: cyme, raceme. Flower: bisexual, radial; sepals generally 5, generally persistent; petals generally 5, free or fused to each other or filament tube; stamens 5--many, filaments thread-like to flat, occasionally fused at base or in clusters; petal-like staminodes occasionally present; pistil 1, ovary inferior, chamber generally 1, placentas generally 3, parietal, style 1. Fruit: capsule or achene. Seed: 1--many.
Genera In Family: 18+ genera, 250 species: especially America (Africa, Pacific).
eFlora Treatment Author: Larry Hufford & Barry Prigge, except as noted
Scientific Editor: Douglas H. Goldman, Bruce G. Baldwin.
Genus: MentzeliaView DescriptionDichotomous Key

Habit: Annual to perennial herb, sometimes subshrub-like; hairs barbed to needle-like, not stinging; stems pale pink or generally +- white, branched or not. Leaf: linear to ovate, entire to pinnate-lobed; basal in rosettes, generally petioled; cauline generally sessile, +- reduced distally on stem. Inflorescence: generally cyme (or flower 1); bracts green to white-centered, margin green. Flower: sepals lanceolate to deltate, persistent; petals generally 5, free, white to yellow or orange; stamens generally many, +- free, generally unequal, inner filaments generally thread-like; outermost stamens opposite sepal lobes often modified, +- widened, or petal-like, with or without anthers or not; ovary generally cylindric, placentas generally 3, style thread-like, stigma 3-furrowed or -lobed. Fruit: capsule, cup-, barrel-, or urn-shaped to narrowly cylindric, occasionally curved. Seed: generally many, shape variable, sometimes winged.

eFlora Treatment Author: Joshua M. Brokaw, John J. Schenk, Barry Prigge & David Keil
Reference: Schenk & Hufford 2020 Syst Bot Monogr 110:1--230
Mentzelia involucrata S. Watson
Habit: Annual 7--35 cm. Stem: erect, hairy. Leaf: 2--18 cm, lanceolate to ovate, generally irregular-toothed. Inflorescence: bracts 4--5 per flower, ovate to obovate, 6--20--toothed, white-scarious, margin +- green. Flower: sepals 7--23 mm; petals 13--62 mm, obovate, +- white to pale yellow, veins generally orange; stamens 4--26 mm, filaments broadened, distally 2-lobed; style 8--30 mm. Fruit: erect, 14--25 mm, 5--10 mm wide, cylindric. Seed: 2--3 mm, 2--2.5 mm wide, +- compressed, middle transverse-ridged, beaked, ashy-white. Chromosomes: 2n=18.
Ecology: Washes, fans, steep slopes, creosote-bush scrub; Elevation: < 900 m. Bioregional Distribution: D (exc DMtns); Distribution Outside California: Arizona, northern Mexico. Flowering Time: Jan--May
Synonyms: Mentzelia involucrata var. involucrata; Mentzelia involucrata var. megalantha I.M. Johnst.
Jepson eFlora Author: Joshua M. Brokaw, John J. Schenk, Barry Prigge & David Keil
Reference: Schenk & Hufford 2020 Syst Bot Monogr 110:1--230
Index of California Plant Names (ICPN; linked via the Jepson Online Interchange)

Previous taxon: Mentzelia hirsutissima
Next taxon: Mentzelia inyoensis

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Botanical illustration including Mentzelia involucratabotanical illustration including Mentzelia involucrata

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Citation for this treatment: Joshua M. Brokaw, John J. Schenk, Barry Prigge & David Keil 2023, Mentzelia involucrata, in Jepson Flora Project (eds.) Jepson eFlora, Revision 12,, accessed on July 20, 2024.

Citation for the whole project: Jepson Flora Project (eds.) 2024, Jepson eFlora,, accessed on July 20, 2024.

Mentzelia involucrata
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©2008 Aaron Schusteff
Mentzelia involucrata
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©2016 Keir Morse
Mentzelia involucrata
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©2009 Keir Morse
Mentzelia involucrata
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©2009 Barry Breckling
Mentzelia involucrata
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©2010 Neal Kramer

More photos of Mentzelia involucrata
in CalPhotos

Geographic subdivisions for Mentzelia involucrata:
D (exc DMtns)
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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 occurrence).


Data provided by the participants of the  Consortium of California Herbaria.

View all CCH records
All markers link to CCH specimen records. The original determination is shown in the popup window.
Blue markers indicate specimens that map to one of the expected Jepson geographic subdivisions (see left map). Purple markers indicate specimens collected from a garden, greenhouse, or other non-wild location.
Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues.

CCH collections by month Flowering-Fruiting Monthly Counts

Duplicates counted once; synonyms included.
Species do not include records of infraspecific taxa, if there are more than 1 infraspecific taxon in CA.
Blue line denotes eFlora flowering time (fruiting time in some monocot genera).