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Key to families | Table of families and genera

Specimen numbers are hyperlinked to records in the Consortium of California Herbaria data view where possible. Taxa are hyperlinked to entries in the Jepson Interchange via the "[Online Interchange]" link.

 

FRAXINUS ASH
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.
± 65 species: temperate. North America, Eurasia, tropical Asia. (Latin: ancient name) [Little 1952 J Washington Acad Sci 42:369–380; Miller 1955 Cornell Univ Agric Exp Sta Mem 335:1–64] 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.

Key to Fraxinus

1. Small to large tree; leaves compound, leaflets (3)4–11(14) cm; fruit pedicel tip expanded; plants with either staminate or pistillate flowers

2. Leaflets ovate, or oblong-(ob)ovate; lateral leaflets ± sessile; fruit body 15–18 mm, 25–50 mm including wing, tapered wing extending proximally to or below mid-body ..... F. latifolia

2' Leaflets lanceolate to lance-ovate or lance-obovate; lateral leaflets generally stalked; fruit body 12–14 mm, 15–38 mm including wing, tapered wing extending proximally to distal 1/4 of body ..... F. velutina

1' Shrub or small tree, stems many; leaves simple or compound, leaflets 2–5(6) cm; fruit pedicel tip ± slender; flowers generally bisexual.

3. Petals generally 0; leaves simple or leaflets 3(5); calyx irregularly cut; n&e Desert Mountains ..... F. anomala

3' Petals 2, white or cream, 3.5–6.5 mm; leaves simple or leaflets 3–9; calyx generally 4-toothed; California Floristic Province

4. Petals and filaments free except at base; leaves, including petioles, 7–18 cm; leaflets (3)5–7(9), generally serrate-crenate ..... F. dipetala

4' Petals fused with proximal filaments for 0.5–1.5 mm at base; leaves, including petioles, 2–5(6) cm, simple and/or leaflets 3; simple leaves and/or leaflets generally entire ..... F. parryi

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Citation for the whole project: Jepson Flora Project (eds.) [year] Jepson eFlora, http://ucjeps.berkeley.edu/IJM.html [accessed on month, day, year]
Citation for an individual treatment: [Author of taxon treatment] [year]. [Taxon name] in Jepson Flora Project (eds.) Jepson eFlora, [URL for treatment]. Accessed on [month, day, year].
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