Ranunculaceae Juss.

Including Nigellaceae J.G. Agardh

Excluding Glaucidiaceae, Hydrastidaceae, Kingdoniaceae

Habit and leaf form. Herbs (mostly), or shrubs (Xanthorhiza), or lianas (Clematis); without essential oils. Annual to perennial; with a basal aggregation of leaves, or with neither basal nor terminal aggregations of leaves; often rhizomatous, or tuberous. Self supporting, or climbing. Hydrophytic to mesophytic; when hydrophytic, rooted. Leaves of aquatics emergent, or submerged, or submerged and floating. Heterophyllous (commonly, when hydrophytic), or not heterophyllous. Leaves alternate (usually), or opposite (Clematis); usually spiral; petiolate; sheathing. Leaf sheaths with free margins. Leaves without marked odour, or foetid; simple, or compound; peltate (more or less, occasionally), or not peltate; epulvinate; when compound pinnate, or palmate, or bipinnate, or multiply compound. Lamina when simple dissected, or entire; when simple/dissected palmately lobed, or much-divided; pinnately veined, or palmately veined; cross-venulate (usually), or without cross-venules. Leaves stipulate (commonly rather conspicuously so), or exstipulate. Stipules intrapetiolar. Lamina margins entire, or crenate, or serrate, or dentate. Leaves without a persistent basal meristem.

Leaf anatomy. Hydathodes present (occasionally), or absent.

Minor leaf veins without phloem transfer cells (Helleborus, Ranunculus).

Stem anatomy. Cork cambium present, or absent. Nodes unilacunar (rarely), or tri-lacunar to multilacunar. Primary vascular tissue comprising a ring of bundles, or in two or more rings of bundles, or in scattered bundles; centrifugal. Secondary thickening absent (commonly), or developing from a conventional cambial ring. Xylem with fibre tracheids; with libriform fibres, or without libriform fibres; with vessels. Vessel end-walls simple (at least usually). Wood partially storied (VP), or not storied. Sieve-tube plastids S-type.

Reproductive type, pollination. Hermaphrodite, or dioecious (rarely, by suppression). Floral nectaries present (usually), or absent (e.g. Anemone, Clematis, Thalictrum). Nectar secretion from the perianth, or from the androecium (from the bases of the petals, considered staminodial in origin). Entomophilous (usually - attracting insects by either nectar or pollen), or anemophilous (e.g. Thalictrum).

Inflorescence, floral, fruit and seed morphology. Flowers solitary (often pedunculate), or aggregated in `inflorescences'; in cymes, or in racemes, or in panicles. The terminal inflorescence unit cymose. Inflorescences scapiflorous, or not scapiflorous; terminal, or axillary; various, but determinate. Flowers small to medium-sized; regular (usually), or somewhat irregular to very irregular (Aconitum etc.); cyclic (Aquilegia), or partially acyclic, or acyclic. When more or less acyclic the perianth acyclic, the androecium acyclic, and the gynoecium acyclic, or the androecium acyclic and the gynoecium acyclic, or the gynoecium acyclic. Floral receptacle not markedly hollowed (convex or elongated). Free hypanthium absent. Hypogynous disk absent.

Perianth with distinct calyx and corolla, or sequentially intergrading from sepals to petals, or sepaline, or petaline; 5-50 (to `many'); free, or joined. Calyx when definable (3-)5-8 (or more, often becoming petaloid); polysepalous, or partially gamosepalous, or gamosepalous; spurred, or neither appendaged nor spurred; persistent, or not persistent; imbricate, or valvate. Corolla when definable 3-50 (to `many' - perhaps staminodal in origin); polypetalous, or partially gamopetalous, or gamopetalous; imbricate; green, or white, or yellow, or red (e.g. some Aquilegia species), or purple, or blue; spurred (occasionally), or not spurred (or with little tubular nectariferous `petals'). Petals clawed, or sessile.

Androecium 15-100 (usually `many'). Androecial members unbranched; maturing centripetally; free of the perianth; free of one another; 1-13 - whorled (or spiralled). Androecium including staminodes. Staminodes usually several or many, if nectaries of various kinds between perianth and stamens are interpreted as such; petaloid, or non-petaloid. Stamens (5-)10-100 (usually `many'). Anthers adnate; non-versatile; dehiscing via longitudinal slits, or dehiscing by londitudinal valves (e.g. Trautvetteria); extrorse, or latrorse; tetrasporangiate. Endothecium developing fibrous thickenings. Microsporogenesis simultaneous. The initial microspore tetrads tetrahedral, or isobilateral, or decussate. Anther wall initially with one middle layer, or initially with more than one middle layer (1 or 2); of the `dicot' type. Tapetum glandular. Pollen grains aperturate (usually), or nonaperturate (Souliea); (2-)3 - aperturate; variously colpate, or foraminate, or rugate, or spiraperturate (but not colporate, not even colporoidate); 2-celled (usually), or 3-celled (occasionally).

Gynoecium (1-)3-100 (i.e. to `many'); monomerous, or apocarpous, or syncarpous; of one carpel (Actaea), or eu-apocarpous (nearly always), or semicarpous (carpels sometimes more or less connate, e.g. Aquilegia), or synovarious (e.g. Nigella); superior. Carpel non-stylate, or stylate; apically stigmatic; (when monomeric or apocarpous) 1 ovuled, or 2-100 ovuled (`several to many'). Placentation when monomeric or apocarpous marginal, or basal. Ovary when syncarpous, 3-5 locular. Styles when syncarpous, 3-5; apical. Stigmas dry type; papillate, or non-papillate; Group II type. Placentation when syncarpous, axile. Ovules when syncarpous, 3-15 per locule (?); pendulous, or horizontal, or ascending; with ventral raphe to with dorsal raphe; non-arillate; hemianatropous, or anatropous; unitegmic, or bitegmic; crassinucellate (when bitegmic), or pseudocrassinucellate (when unitegmic). Embryo-sac development Polygonum-type, or Allium-type. Polar nuclei fusing prior to fertilization. Antipodal cells formed; 3 (sometimes multinucleate); proliferating (rarely), or not proliferating. Synergids pear-shaped, or hooked (sometimes with filiform apparatus). Endosperm formation nuclear. Embryogeny onagrad (or undifferentiated).

Fruit non-fleshy (usually), or fleshy (rarely); multiple (usually), or not multiple. The fruiting carpel dehiscent, or indehiscent; a follicle, or an achene, or baccate (Actaea). Fruit when syncarpous a capsule (e.g. Nigella). Seeds copiously endospermic. Endosperm oily. Seeds without amyloid. Embryo rudimentary at the time of seed release to weakly differentiated, or well differentiated. Cotyledons 1 (occasionally), or 2 (often connate). Embryo achlorophyllous (14/25); straight.

Seedling. Germination phanerocotylar, or cryptocotylar.

Physiology, biochemistry. Cyanogenic, or not cyanogenic. Cynogenic constituents tyrosine-derived (including triglochinin). Alkaloids present (mostly), or absent. Berberine present (at least in the rhizome of Coptis), or absent. Iridoids absent. Proanthocyanidins absent (usually), or present (e.g. Clematis); when present, cyanidin. Flavonols present (mostly), or absent; kaempferol, or quercetin, or kaempferol and quercetin (nearly always both). Ellagic acid absent (13 species, 9 genera). Arbutin absent. Saponins/sapogenins present, or absent. Aluminium accumulation not found. C3. C3 recorded in Anemone, Clematis, Delphinium, Ranunculus. Anatomy non-C4 type (Anemone, Delphinium, Ranunculus).

Geography, cytology. Frigid zone to tropical. Cosmopolitan, concentrated in the North temperate.

Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren's Superorder Ranunculiflorae; Ranunculales. Cronquist's Subclass Magnoliidae; Ranunculales. Takhtajan's Subclass Ranunculidae; Ranunculanae; Ranunculales. Species 1500. Genera about 50; Aconitum, Actaea, Adonis, Anemone, Anemonopsis, Aquilegia, Archiclematis, Asteropyrum, Barneoudia, Beesia, Calathodes, Callianthemum, Caltha, Ceratocephala, Cimicifuga, Clematis, Clematopsis, Consolida, Coptis, Delphinium, Dichocarpum, Enemion, Eranthis, Hamadryas, Helleborus, Hepatica, Isopyrum, Knowltonia, Komaroffia, Krapfia, Kumlienia, Laccopetalum, Leptopyrum, Megaleranthis, Metanomone, Miyakea, Myosurus, Naravelia, Nigella, Oreithales, Paraquilegia, Paroxygraphis, Pulsatilla, Ranunculus, Semiaquilegia, Souliea, Thalictrum, Trautvetteria, Trollius, Urophysa, Xanthorhiza.

Economic uses, etc. Many cultivated ornamentals (Ranunculus, Anemone, Helleborus, Trollius, Delphinium, Aconitum, Aquilegia, some (e.g. Aconitum) supply poisonous narcotic drugs.

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