Jepson eFlora: Taxon page
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Mentzelia torreyi

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; 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, 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 generally modified, +- widened, or petal-like with anther 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.
Species In Genus: +- 100 species: western North America, +- tropical America.
eFlora Treatment Author: Joshua M. Brokaw, John J. Schenk & Barry Prigge

Mentzelia torreyi A. Gray
Habit: Perennial herb 10--20 cm. Stem: many from thick caudex, erect to decumbent, hairy. Leaf: 2--4 cm, generally deeply pinnate-lobed, 0--7 linear lobes, margins rolled under. Inflorescence: bracts linear, base occasionally 2-lobed, margins rolled under, green. Flower: sepals 3--6 mm; petals 9--15 mm, oblanceolate, orange to pale yellow, abaxially puberulent; stamens 7--10 mm; style 8--12 mm. Fruit: +- erect, 4--8 mm, 3--6 mm wide, urn-shaped, gradually narrowing. Seed: 2--2.5 mm, +- fusiform, +- spiral-3-ribbed, acute distally, truncate proximally. Chromosomes: 2n=28.
Ecology: Sandy to alkaline fine-textured, slopes, scrub, pinyon woodland; Elevation: 900--2100 m. Bioregional Distribution: SNE; Distribution Outside California: to Oregon, Idaho. Flowering Time: Jun--Aug
eFlora Treatment Author: Joshua M. Brokaw, John J. Schenk & Barry Prigge
Jepson Online Interchange
Listed on CNPS Rare Plant Inventory

Previous taxon: Mentzelia reflexa
Next taxon: Mentzelia tricuspis

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botanical illustration including Mentzelia torreyi


Citation for this treatment: Joshua M. Brokaw, John J. Schenk & Barry Prigge 2016. Mentzelia torreyi, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on May 02, 2016.

Citation for the whole project: Jepson Flora Project (eds.) 2016. Jepson eFlora,, accessed on May 02, 2016.

Mentzelia torreyi
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© 2009 Keir Morse
Mentzelia torreyi
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© 2008 Steve Matson
Mentzelia torreyi
click for enlargement
© 2009 Keir Morse
Mentzelia torreyi
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© 2009 California Academy of Sciences
Mentzelia torreyi
click for enlargement
© 2008 Steve Matson
Mentzelia torreyi
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© 2010 Aaron Schusteff

More photos of Mentzelia torreyi in CalPhotos

Geographic subdivisions for Mentzelia torreyi:
Markers link to CCH specimen records. If the markers are obscured, reload the page [or change window size and reload]. Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues.
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.