Herbs , annual or perennial, from tuberous roots, caudices, rhizomes, stolons, or bulbous stem bases. Leaves basal, cauline, or both, simple, variously lobed or parted, or compound, all petiolate or distal leaves sessile; cauline leaves alternate (rarely a distal pair opposite in Ranunculus sect. Flammula ). Leaf blade reniform to linear, margins entire, crenate, or toothed. Inflorescences terminal or axillary, 2-50-flowered cymes to 25 cm or solitary flowers; bracts present or absent, small or large and leaflike, not forming involucre. Flowers bisexual, radially symmetric; sepals sometimes persistent in fruit, 3-5(-6), green or sometimes purple, yellow, or white, plane (base saccate in R . ficaria ), oblong to elliptic, ovate, or lanceolate, 1-15 mm; petals 0-22(-150), distinct, yellow, rarely white, red, or green, plane, linear to orbiculate, 1-26 mm; nectary present, usually covered by scale; stamens (5-)10-many; filaments filiform; staminodes absent between stamens and pistils; pistils 4-250, simple; ovule 1 per ovary; style present or absent. Fruits achenes, rarely utricles, aggregate, sessile, discoid, lenticular, globose, obovoid, or cylindric, sides sometimes veined; beak present or absent, terminal, straight or curved, 0-4.5 mm. x = 7, 8.
Glabrous to pubescent erect or procumbent herbaceous annuals or perennials, the stems occasionally rooting at the nodes, the roots fibrous, fascicled. Leaves radical or cauline, exstipulate, entire, dissected or compound, alternate or rarely opposite, glabrous to pubescent, often with acrid juice. Inflorescence terminal, the flowers perfect; sepals 5(-3-6), imbricate, caducous; petals (O-)5(-26), yellow, white or red, separate, with a nectariferous pit at the base, unguiculate; stamens commonly 10, often more, rarely fewer; anthers 2-celled, basifixed, longitudinally dehiscent; carpels 5-many, the single ovule attached near the base of the cell. Achenes capped by the elongate style, glabrous or hairy, smooth or variously ornate.
"Fls regular; sep green or yellowish, 3, 4, or more commonly 5, rarely more; pet mostly 5, sometimes fewer or more, each with a nectariferous pit or scale on the upper side at the base; stamens mostly numerous, rarely as few as 5; pistils numerous in a globose, ovoid, or cylindric head; ovule ordinarily 1, erect or ascending; fr an achene; annual or perennial herbs with alternate, entire to much dissected lvs and yellow, white, or rarely red fls; juice acrid, poisonous. (Batrachium, Ceratocephalus, Ficaria) 250+, ± cosmop."
Herbs perennial or annual, terrestrial or rarely aquatic. Stems usually leafy. Leaves usually both basal and along stem, lower leaves petiolate, petiole expanded into sheath at base; leaf blade simple, palmately divided, 1- or 2-ternate or, rarely, pinnate. Inflorescence a solitary terminal or leaf-opposed flower, or a simple or compound monochasium. Flowers bisexual, actinomorphic. Receptacle ± convex, sometimes forming androgynophore (Ranunculus angustisepalus). Sepals (3--)5(--7), usually greenish, occasionally dark reddish or purple, very rarely abaxial sepal appendiculate (R. angustisepalus), deciduous or, rarely, persistent. Petals (3--)5(--10), yellow, rarely white, exceptionally red (not in Flora area), base shortly clawed, with foveolate adaxial nectary pit which is sometimes covered by a scale. Stamens numerous or rarely few. Carpels numerous, sessile or rarely stalked (R. podocarpus); ovule 1 per carpel, basal; style usually present, with adaxial stigmatic tissue, sometimes absent; distinct stigma usually absent. Fruit aggregate, globose, ovoid, or cylindric, with numerous achenes. Achenes ovoid, obovoid, or slightly to strongly bilaterally compressed, smooth, sometimes tuberculate or spiny, sometimes marginate or winged along sutures, usually greenish, black in R. melanogynus. Seeds with a copious endosperm and small embryo.
Perennial herbs with simple or compound petiolate radical leaves and spirally arranged cauline leaves with sheathing bases.
Petals 5–8 or more, usually yellow or white with a basal nectariferous pit with or without a scale.
Sepals spreading or reflexed in anthesis.
Flowers actinomorphic in 1-many-flowered inflorescences.
Fruit of numerous achenes with usually glabrous styles.
Carpels indefinite in number, 1-ovulate.
Achenes with persistent, glabrous, sometimes hooked style.
Sepals spreading or reflexed in anthesis
Petals 5–8 or more, white, yellow, or with anthocyanin colours, with basal nectariferous pit with or without a scale
Herbs with simple or compound spirally arranged leaves, usually ex-stipulate
Carpels indefinite in number, uniovulate
Comprised of about 250 species in temperate and subarctic regions of both hemispheres, the buttercup genus is represented in Central America by few species, most of them confined to moderately high elevations. In his recent monograph of the North American species, Benson (in Am. Midl. Nat. 40: 1. 1948, and 52: 328. 1954) treats about 100 species.
Benson, L. D. 1948. A treatise on the North American Ranunculi. Amer. Midl. Naturalist 40: 1-261. Benson, L. D. 1954. Supplement to a treatise on the North American Ranunculi. Amer. Midl. Naturalist 52: 328-369. Cook, C. D. K. 1966. A monographic study of Ranunculus subgenus Batrachium (DC.) A. Gray. Mitt. Bot. Staatssamml. München 6: 47-237. Duncan, T. 1980. A taxonomic study of the Ranunculus hispidus Michaux complex in the Western Hemisphere. Univ. Calif. Publ. Bot. 77: 1-125. Nesom, G. L. 1993. Ranunculus (Ranunculaceae) in Nuevo León, with comments on the R. petiolaris group. Phytologia 75: 391-398.
|Buttercup, crowfoot, renoncule [Latin rana, frog, unculus, little, allusion to the wet habitats in which some species grow]|