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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.

 

ARABIS ROCKCRESS
Annual, biennial, perennial herb; base not woody; hairs simple, forked, or stellate; caudex branched or not. Stem: branched or not, leafy. Leaf: basal rosetted, petioled, entire or dentate; cauline sessile, entire or dentate, base lobed or not. Flower: sepals erect or ascending, base of lateral pair sac-like or not; petals spoon-shaped to oblong, oblanceolate, or obovate, white to pink or deep purple. Fruit: silique, erect to spreading, linear, dehiscent, unsegmented, straight, flat parallel to septum, glabrous. Seed: 12–110, 1 row per chamber, flat, winged or margined.
< 70 species: temperate North America, Eurasia, northern Africa. (Latin: of Arabia) Most species of Arabis in TJM (1993) moved to Boechera; Arabis glabra to Turritis. California record of Arabis aculeolata Greene not confirmed.

Key to Arabis

1. Cauline leaf bases lobed or sagittate

2. Petals (5.5)6.5–9(10) mm; bases of lateral sepal pair sac-like; fruit 1.2–2 mm wide; cauline leaves (2)4–12(18), generally well-spaced ..... A. eschscholtziana

2' Petals 3.5–5(5.5) mm; sepal base not sac-like; fruit 0.8–1(1.2) mm wide; cauline leaves (7)10–45(61), generally overlapping ..... A. pycnocarpa var. pycnocarpa

1' Cauline leaf bases tapered, not lobed or sagittate

3. Hairs of basal leaves stellate, 3- or 4-rayed ..... A. modesta

3' Hairs of basal leaves simple to 2(4)-rayed or 0

4. Seeds ± round, 2–2.5 mm; fruit 2–3 mm wide ..... A. blepharophylla

4' Seeds oblong, 1–1.3 mm wide; fruit 1.5–2 mm wide

5. Plant glabrous or with a few simple hairs at teeth tips of basal leaves; fruit 2–4 cm ..... A. mcdonaldiana

5' Plant moderately to densely hairy, hairs simple, forked; fruit (3)4.5–5 cm ..... A. oregana

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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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