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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.

 

EUCALYPTUS EUCALYPTUS, GUM TREE

Matt Ritter


Tree, shrub. Stem: generally erect; bark shedding, smooth, or persistent near base (occasionally) or throughout, rough; twigs generally round. Leaf: juvenile generally opposite, horizontal, sessile, ± cordate, entire, glaucous; adult generally alternate, vertical, petioled, ± lanceolate, entire, glandular, glabrous, generally same color on both sides. Inflorescence: axillary, (1)3–many-flowered, stalked umbel or panicle-like cluster of such umbels. Flower: perianth (generally, entirety of calyx lobes, petals) fused into bud cap in bud, bud cap shed at flower; stamens many, in several series, generally all fertile, white (yellow, red, pink); ovary chambers 3–6, fused to hypanthium. Fruit: capsule, thick-walled, woody, generally smooth, generally dehiscing at top. Seed: generally 1–3 mm, wind-dispersed.
± 700 species: most endemic to Australia; > 250 species. Cult in California; important for oils, tannins, timber, orns. (Greek: true cap, for bud cap) [Brooker 2000 Austral Syst Bot 13:79–148] World's largest flowering plants, some > 100 m; Eucalyptus pulverulenta Sims excluded, cultivated only.

Key to Eucalyptus

1. Inflorescence a panicle of 3–many-flowered umbels

2. Leaves lanceolate, lemon-scented; bark smooth ..... E. citriodora

2' Leaves ovate, elliptic, or round, not lemon-scented; bark rough ..... E. polyanthemos

1' Inflorescence a 3–many-flowered umbel or flowers 1 in axils

3. Flowers 1 in leaf axils, ± sessile; fruit glaucous, > 1.5 cm wide ..... E. globulus

3' Flowers 3–many in stalked umbels; fruit not glaucous, < 1 cm wide

4. Bark deeply furrowed, dark brown to ± black; anthers 0 on outer stamens ..... E. sideroxylon

4' Bark smooth, shedding, occasionally rough near base, mottled, gray, white, orange, or tan; anthers on all stamens

5. Fls, fruit fused at base into cluster 3–6 cm wide ..... E. conferruminata

5' Fls, fruit all free at base

6. Hypanthium cylindric or urn-shaped; leaves lighter abaxially ..... E. cladocalyx

6' Hypanthium obconic, ovoid, or hemispheric; leaves same color on both sides

7. Inflorescence a 3-flowered umbel ..... E. viminalis

7' Inflorescence a 5–15-flowered umbel

8. Leaves linear, generally < 0.5 cm wide; fruit valves not exserted ..... E. pulchella

8' Leaves lanceolate, generally > 1 cm wide; fruit valves exserted

9. Bud cap hemispheric, beaked, ± = hypanthium ..... E. camaldulensis

9' Bud cap horn-shaped to conic, not beaked, ± 2 × hypanthium ..... E. tereticornis

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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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