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Ranunculaceae
See list of 18 genera in this familyReference: Mitchell and Dean (1982).
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1a. Plants woody, with yellow inner bark; fruit a sparsely pubescent follicle
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1b. Plants herbaceous; fruit an achene, berry, or glabrous follicle
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3a. Calyx composed of 5 spurred sepals; receptacle continuing to elongate through and after anthesis, the cluster of achenes becoming slender-conical and 16–50 ×1–3 mm
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3b. Calyx composed of 4–20 sepals that are not spurred; receptacle not continuing to elongate after anthesis, the cluster of achenes relatively broader compared with length
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4a. Petals present, yellow or both white and yellow; sepals (3–) 5, sepaloid
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5b. Flowers with 3 (–4) sepals; achenes either beakless or with a prominent, corky appendage distal to the seed
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6a. Flowers with 5–8 petals; leaf blades prominently lobed with deep sinuses [Fig. 813]; roots all slender; achenes with both a terminal beak and a prominent, corky appendage prolonged distal to the seed
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6b. Flowers with 7–11 petals; leaf blades entire to crenate; some roots tuberous-thickened; achenes lacking both a terminal beak and a corky appendage distal to the seed
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4b. Petals absent or inconspicuous; sepals 4–20, petaloid or sepaloid in some species of Thalictrum
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7a. Plants trailing or climbing vines; sepals valvate in bud; style plumose [Fig. 812]; stem leaves opposite
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7b. Plants upright, not vining; sepals imbricate in bud; style not plumose; stem leaves alternate or lacking (note: the opposite or whorled leaves found on the stems of some Thalictrum and Anemone are involucral leaves associated with the inflorescence)
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8a. Stem leaves alternate; sepals 1.5–5 mm long, often inconspicuous and sometimes caducous (in part)
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8b. Stem leaves lacking, but appearing opposite or whorled in most species (these leaves actually involucral bracts associated with the inflorescence); sepals 5–25 mm long, conspicuous, usually persisting through anthesis
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9a. Leaf blades palmately lobed or palmately compound (subternately divided in A. multifida); style present; achenes lacking evident veins on lateral surfaces
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9b. Leaf blades pinnately compound in ternate fashion [Fig. 821]; style absent (i.e., the stigma sessile); achenes with evident veins or ribs on lateral surfaces (in part)
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2b. Fruit a follicle, capsule, or berry [Fig. 807]; ovaries with 2 or more ovules
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10a. Flowers zygomorphic
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11a. Upper sepal arched or hooded; petals not spurred
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11b. Upper sepal neither arched nor hooded, prolonged into a spur; upper petal or all the petals spurred
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12a. Flowers with 4 distinct petals and 3 carpels; ultimate lobes of leaf blades 5–25 mm wide; plants perennial, from fasciculate roots
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12b. Flowers with 2 connate petals and 1 carpel; ultimate lobes of leaf blades narrower than 1.5 mm; plants annual, from a slender taproot
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10b. Flowers actinomorphic
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13a. Leaf blades pinnately dissected into filiform segments; gynoecium of 5–10 connate carpels; fruit a capsule
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13b. Leaf blades toothed to divided, but the divisions not threadlike; gynoecium of 1–15 distinct carpels; fruit a follicle or berry
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14b. Leaf blades simple or compound, but not palmately lobed; perianth either with both sepals and petals present or with 4–9 petaloid sepals; inflorescence either with 2 or more flowers or a solitary flower borne on a scape (solitary and terminal in Trollius and also rarely in Caltha); mature fruit a follicle or berry (a red berry in some Actaea)
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15a. Leaf blades not pinnately compound, either simple or palmately divided; calyx composed of 5–9 petaloid, pale yellow to bright yellow or orange-yellow sepals
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16a. Leaf blades palmately divided to the base; flowers with 10–15 (–25) yellow staminodes 3–6 mm long; inflorescence with a solitary, terminal flower
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16b. Leaf blades simple; flowers lacking staminodes; inflorescence terminal or both terminal and axillary, with 1–7 flowers
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15b. Leaf blades pinnately compound, often in ternate fashion; perianth not yellow, the calyx with 5 or fewer sepals
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17b. Perianth conspicous, not caducous, the petaloid sepals (4–) 5–25 mm long; inflorescence a solitary flower or a 1- to 10-flowered cyme; fruit a follicle; ultimate segments of leaves crenately toothed or crenately lobed
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18a. Sepals red or blue to people (rarely white); petals conspicuous, prolonged into long spurs [Fig. 811], 15–31 mm long including the spur; leaves borne on an aerial, leafy stem, the blades 2- or 3-times compound
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18b. Sepals white; petals represented by small, clavate-spatulate staminodia, without spurs, 2.5–3 mm long; leaves all basal, the blades once-compound
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Each photo represents one genus in this family.