Jepson eFlora: Taxon page
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Fraxinus dipetala

Higher Taxonomy
Family: OleaceaeView DescriptionDichotomous Key

Habit: Perennial herb to tree [vine], hairs 0 or peltate or not; rarely dioecious. Leaf: simple to odd-pinnately compound, alternate or generally opposite, deciduous or evergreen; stipules 0. Inflorescence: various; flowers >= 1. Flower: generally bisexual, generally radial; calyx generally minute (0), tube cup-shaped, lobes 4--15; petals (0)4--6(8), generally fused; nectar disk often present; stamens (0)2(4--5), epipetalous; pistil 1, ovary superior, chambers 2, each 2--4 ovuled, placenta axile, style 1, stigma generally 2-lobed. Fruit: drupe, capsule, or winged achene. Seed: 1 per chamber.
Genera In Family: +- 25 genera, 900 species: +- worldwide; some cultivated for ornamental (Forsythia; Jasminum, jasmine; Ligustrum, privet; Syringa, lilac) or food (Olea, olive).
eFlora Treatment Author: Family description, key to genera by Thomas J. Rosatti; treatment of genera by James Henrickson, except as noted
Scientific Editor: Bruce G. Baldwin.
Genus: FraxinusView DescriptionDichotomous Key

Common Name: ASH
Habit: Shrub or tree; generally dioecious, often bisexual (in California). Stem: older bark smooth or becoming furrowed, generally gray; lenticels broadly elliptic; twigs cylindric to 4-angled, glabrous to hairy; developing short-shoot spurs. Leaf: simple or generally odd-pinnate, opposite, deciduous; petioles channeled, occasionally winged, hairy or not; if compound, leaflets (1)3--9, lanceolate to ovate or obovate, generally acute to acuminate at tip, entire or +- crenate-serrate, generally dark green adaxially, pale abaxially, thin to +- leathery in drier habitats, generally glabrous or with simple hairs abaxially or throughout, proximal opposite on rachis, stalked or not, terminal generally largest, stalk longer. Inflorescence: axillary, of clusters or long-branched panicles; flowers pedicelled. Flower: unisexual or bisexual; calyx 1--2 mm, shallowly +- 4-lobed to cut, persistent on fruit; petals 0, 2, or 4, free or fused to basal filaments. Staminate Flower: stamens 2(3); pistil vestigial. Pistillate Flower: stamens 0; style slender; ovules 2 per chamber. Fruit: achenes, winged, wings generally flat, extending to tip or base of seed-containing chamber. Seed: generally 1.
Species In Genus: +- 65 species: temperate. North America, Eurasia, tropical Asia. Etymology: (Latin: ancient name) Note: Fraxinus uhdei (Wenzig) Lingelsheim, Mexican ash, cultivated in western United States; similar to Fraxinus velutina, with +- larger leaves and leaflets, generally with stiff hairs to 0.5 mm bordering abaxial midvein and occasionally 2° veins abaxially (as occasionally in Fraxinus velutina), and +- larger fruit, but margins tapered to near base of fruit body; native northern Mexico to Honduras.

Fraxinus dipetala Hook. & Arn.
Habit: Shrub to small tree, 1.5--3(6) m. Stem: older stem bark gray, smooth; twigs cylindric to 4-angled, gray; buds +- glandular-puberulent. Leaf: compound, 7--18 cm, 5--9(11) cm wide; petiole 2.4--4.5 cm; leaflets (3)5--7(9), 2--4.5 cm, 1--2.5 cm wide, ovate to +- rounded, tapered at base, obtuse to +- rounded at tip, generally serrate-crenate, generally thin, glabrous, dark green adaxially, pale abaxially. Inflorescence: 8--15 cm. Flower: generally bisexual; calyx 1.2--2 mm, +- toothed, thin, green; petals 2, 3.5--6.5 mm, 1.3--3 mm wide, oblong-ovate, cream-white, +- cupped, narrowed and fused with filaments at base (rarely forming basal tube); anthers 2.4--4.2 mm; filaments 0.8--2.8 mm; stigmas +- < style. Fruit: 20--32 mm, 5--9 mm wide; body broadly oblanceolate, flat, broadly winged to near base; fruit pedicel tip slender. Chromosomes: 2n=46.
Ecology: Canyons, slopes, chaparral, oak/pine woodland; Elevation: 100--1300 m. Bioregional Distribution: KR, NCoR, CaR, SNF, c&s SN, CW, TR, PR. Flowering Time: Apr--Jun
eFlora Treatment Author: Family description, key to genera by Thomas J. Rosatti; treatment of genera by James Henrickson
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botanical illustration including Fraxinus dipetala


Citation for this treatment: Family description, key to genera by Thomas J. Rosatti; treatment of genera by James Henrickson 2017. Fraxinus dipetala, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on October 23, 2017.

Citation for the whole project: Jepson Flora Project (eds.) 2017. Jepson eFlora,, accessed on October 23, 2017.

Fraxinus dipetala
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© 2014 Julie Kierstead Nelson
Fraxinus dipetala
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© 2011 Vernon Smith
Fraxinus dipetala
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© 2016 Julie Kierstead Nelson
Fraxinus dipetala
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© 2009 Keir Morse
Fraxinus dipetala
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© 2014 Neal Kramer
Fraxinus dipetala
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© 2016 Julie Kierstead Nelson

More photos of Fraxinus dipetala in CalPhotos

Geographic subdivisions for Fraxinus dipetala:
KR, NCoR, CaR, SNF, c&s SN, CW, TR, PR.
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.
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.