TREATMENT FROM THE JEPSON MANUAL	previous taxon | next taxon Jepson Interchange (more information)
	©Copyright 1993 by the Regents of the University of California Print edition is available from the University of California Press

	The second edition of The Jepson Manual (2012) is available from the University of California Press
	See also the Jepson eFlora, which parallels the Second Edition

RANUNCULACEAE

BUTTERCUP FAMILY

Dieter H. Wilken, except as specified

Annual, perennial herb, sometimes aquatic
Leaves generally basal and cauline, generally alternate, simple or compound; petioles at base generally flat, sometimes sheathing or stipule-like
Inflorescence: cyme, raceme, panicle, or flowers solitary
Flower generally bisexual, radial; sepals generally 5, free, early deciduous or withering in fruit, generally green; petals 0–many, free; stamens generally 10–many; pistils 1–many, ovary superior, chamber 1, style 1, generally ± persistent in fruit as beak, ovules 1–many
Fruit: achene, follicle, berry, or utricle-like, 1–many-seeded
Genera in family: ± 60 genera, 1700 species: worldwide, especially n temp, tropical mtns; many ornamental (Adonis, Aquilegia, Clematis, Consolida, Delphinium, Erianthis, Helleborus ), some highly TOXIC (Aconitum, Actaea, Delphinium, Ranunculus )
Reference: [Duncan & Keener 1991 Phytologia 70:24–27]

RANUNCULUS

BUTTERCUP

Annual, perennial herb, sometimes from stolons or caudices, terrestrial or aquatic; roots generally fibrous
Stem prostrate to erect
Leaves basal and generally cauline, generally reduced upwards, generally glabrous; petiole base flat, stipule-like or not; basal and lower cauline petioles generally long; blades simple to dissected or compound, entire to toothed
Inflorescence: cyme, axillary or terminal, 1–few-flowered
Flower radial; sepals generally 5, generally early deciduous, generally glabrous, generally green to yellowish; petals generally 5, generally > sepals, generally white to yellow, shiny; nectar gland near petal base, pocket-like or with flap-like scale; anthers yellow; pistils generally many
Fruit: achene, generally compressed, beaked, generally glabrous; walls thick
Species in genus: ± 250 species: temp worldwide, tropical mtns; some ornamental
Etymology: (Latin: (Pliny) little frog, from generally wet habitats)

Introduced

R. arvensis L.

Annual or biennial 10–40 cm; roots 3–4.5 mm wide above, tapered
Stem generally erect; branches 0–few; hairs 0–sparse
Leaves: hairs 0 or sparse, appressed; basal and lower cauline petioles 1–4.5 cm, blades 1.5–6 cm, ± ovate to wedge-shaped, entire to deeply lobed or dissected, lobes or segments 3, entire to few-toothed or -lobed; upper cauline leaves generally deeply 3-lobed, lobes linear to (ob)lanceolate
Flower: receptacle glabrous, tip puberulent; sepals 3.5–6 mm, short-hairy; petals 6–8 mm, 2.5–3.5 mm wide
Fruits 4–10; cluster spheric; body 4–6 mm, sides ± 3 mm wide, spiny; keel thick, few-spined; beak 2–3 mm, curved
Ecology: Waste places, fields, ditchbanks
Elevation: < 1000 m.
Bioregional distribution: Klamath Ranges, Outer North Coast Ranges, Cascade Range, Sierra Nevada Foothills, Outer South Coast Ranges, expected elsewhere
Distribution outside California: to Washington, Idaho, Utah, also e US; native to Europe