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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.


Tree, shrub, with stipular spines at nodes or thorns in leaf axis (see leaf scars) or main leaf axis a strong spine. Stem: ± zigzag; bark smooth, green. Leaf: alternate or in clusters of 1–6 in spine axils, generally even-2-pinnate, sometimes appearing 1-pinnate, main axis flat, leaflets alternate, falling early or not; 1° leaflets 2–6; 2° leaflets 4–many. Inflorescence: raceme, axillary, generally < 7-flowered. Flower: ± bilateral; sepals ± free, alike, generally reflexed; petals ± equal, generally yellow or cream-white; stamens 10, yellow to orange, free, exserted. Fruit: indehiscent to partly late-dehiscent, generally flat, oblong, ± inflated, narrowed between seeds or not. Seed: 1–several.
11–12 species, 2 named hybrids: America, southern United States to Argentina, Africa; cultivated. (J. Parkinson, London, apothecary, author, 1567–1650) [Haston et al. 2005 Amer J Bot 92:1359–1371; Hawkins 1996 Ph.D. Dissertation, Univ Oxford, UK] Haston et al., Hawkins support treatment of Cercidium and Parkinsonia, both recognized in TJM (1993), as single, monophyletic genus.
Unabridged references: [Carter 1974 Proc Calif Acad Sci 40(2):17–57; Haston et al. 2005 Amer J Bot 92:1359–1371; Hawkins 1996 Ph.D. Dissertation, Univ of Oxford, UK]
Unabridged note: Since S. Watson (1870s), Cercidium and Parkinsonia have variously been treated as 1 or 2 genera; Carter 1974 and McClintock in TJM (1993) recognized both genera but work of Hawkins 1996 (Ph.D. Dissertation, Univ. Oxford, UK) and Haston et al. 2005 (Amer J Bot 92:1359–1371) support treatment as 1 monophyletic group.

Key to Parkinsonia

1. Plant with spines at nodes; leaves 10–30 cm; 2° leaflets 30–60 ..... P. aculeata

1' Plant with thorns in leaf axils or thorn-tipped branches; leaves 1–5 cm or 0; 2° leaflets 2–6 or 8–16

2. Leaf petioled; 2° leaflets 2–6, 4–8 mm; plant with thorns in leaf axils; fruit ± not narrowed between seeds ..... P. florida

2' Leaf sessile; 2° leaflets 8–16, 1–5 mm; plant with thorn-tipped branches; fruit narrowed between seeds ..... P. microphylla


Citation for the whole project: Jepson Flora Project (eds.) [year] Jepson eFlora, [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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