| | 1. Flowers in simple umbels or heads, rarely spikes or racemes; fruit central axis not an obvious structure |
| |
| | 2. Leaf not truly sheathing at base but stipules present, sometimes slightly fused above node when leaves opposite |
| |
| | 3. Herbage hairs stellate; fruit not or slightly compressed front-to-back, inflated |
| BOWLESIA (no key) |
| | 3' Herbage hairs simple or 0; fruit very compressed side-to-side |
| HYDROCOTYLE |
| | 2' Leaf conspicuously sheathing at base, stipules 0 |
| |
| | 4. Flowers in open umbels; fruit glabrous, with well defined, thickened ribs |
| LILAEOPSIS |
| | 4' Flowers in dense umbels or heads; fruit with scales, prickles, or tubercles, without distinct ribs |
| |
| | 5. Flowers individually accompanied by a single bractlet, bisexual, sessile |
| ERYNGIUM |
| | 5' Flowers not individually accompanied by a single bractlet, bisexual and staminate (or staminate only) in same umbel or head, staminate often long-pedicelled |
| SANICULA |
| | 1' Flowers in compound umbels (these sometimes head-like), sometimes simple umbels as well; fruit central axis generally an obvious, separate structure |
| |
| | 6. Annual or biennial, from slender taproot or fibrous roots, reproducing solely from seed |
| |
| |
| | 8. Leaf pinnately dissected into thread-like segments; bractlets 0 |
| ANETHUM (no key) |
| | 8' Leaf simple, entire; bractlets leaf-like, > flowers, fruits |
| BUPLEURUM (no key) |
| | 7' Corolla white, greenish white, reddish, or rose-tinged |
| |
| | 9. Fruit generally elongate, much longer than wide, beaked or long-tapered to tip |
| |
| | 10. Bractlets entire; fruit ribs 0 or obscure, sterile beak << fertile body |
| ANTHRISCUS (no key) |
| | 10' Bractlets lobed or dissected; fruit ribs prominent, sterile beak > fertile body |
| SCANDIX (no key) |
| | 9' Fruit ± round to oblong or elliptic, not or only slightly longer than wide, not beaked, not long-tapered to tip |
| |
| | 11. Fruit ± round, not compressed, halves not separating readily |
| CORIANDRUM (no key) |
| | 11' Fruit ovate or cordate to oblong or elliptic, compressed either side-to-side or front-to-back, halves separating readily |
| |
| | 12. Bracts leaf-like, generally dissected |
| |
| | 13. Fruit glabrous; herbage glabrous |
| AMMI |
| | 13' Fruit conspicuously bristly; herbage hairy |
| |
| | 14. Fruit very compressed front-to-back; rays generally many; umbel dense, nest-like in fruit |
| DAUCUS |
| | 14' Fruit compressed side-to-side; rays few (1–9); umbel open, not nest-like in fruit |
| YABEA (no key) |
| | 12' Bracts 0 or inconspicuous, not leaf-like |
| |
| | 15. Leaves mostly opposite; rays 2–3; fruit elliptic-cordate |
| APIASTRUM (no key) |
| | 15' Leaves mostly alternate; rays 2–14; fruit oblong-ovate or ovate |
| |
| | 16. Petals very wide, tips narrowed, incurved; fruit covered or half covered with prickles; herbage hairy |
| TORILIS |
| | 16' Petals narrow, tips not narrowed, not incurved; fruit covered with prickles, or sharply scabrous, or glabrous; herbage glabrous or ± roughened but not hairy |
| |
| | 17. Involucel 0; fruit glabrous |
| CICLOSPERMUM (no key) |
| | 17' Involucel present; fruit conspicuously bristly or sharply scabrous, at least on ribs |
| |
| | 18. Inflorescence except fruits puberulent or minutely hairy; fruit oblong-ovate |
| AMMOSELINUM (no key) |
| | 18' Inflorescence except fruits glabrous; fruit widely ovate |
| SPERMOLEPIS (no key) |
| | 6' Perennial or biennial, from various, persistent, often swollen, tuberous underground structures, as well as reproducing from seed |
| |
| | 19. Plant glabrous, generally in wet or moist soil of marshes, streambanks, etc. or where water stands for long periods; corolla white |
| |
| | 20. Stem generally conspicuously purple-spotted or -streaked; herbage musty-scented; fruit oil tubes not apparent |
| CONIUM (no key)2 |
| | 20' Stem green or sometimes purplish but unspotted; herbage not musty-scented; fruit oil tubes apparent |
| |
| | 21. Stems from well developed single or from clustered tubers or clustered, tuberous or fibrous roots, generally not rooting at lower nodes |
| |
| | 22. Calyx lobes forming persistent crown on fruit; fruit corky; fruit central axis not an obvious structure |
| OENANTHE |
| | 22' Calyx lobes evident but not forming persistent crown on fruit; fruit not evidently corky; fruit central axis an apparent separate structure |
| |
| | 23. Fruit very compressed front-to-back, marginal ribs widely thin-winged |
| OXYPOLIS (no key) |
| | 23' Fruit slightly or not compressed side-to-side, ribs subequal, thread-like to prominent but not clearly winged |
| PERIDERIDIA |
| | 21' Stems from stout taproots or rooting at lower nodes or along rhizomes or stolons |
| |
| | 24. Calyx lobes forming persistent crown on fruit; fruit central axis not an obvious structure |
| OENANTHE |
| | 24' Calyx lobes 0 or minute, generally not forming a persistent crown on fruit; fruit central axis an apparent separate structure |
| |
| | 25. Bracts, bractlets conspicuous; fruit halves generally adhering to central axis |
| |
| | 26. Fruit ribs thread-like, inconspicuous in corky fruit wall |
| BERULA (no key) |
| | 26' Fruit ribs prominent, corky |
| SIUM (no key) |
| | 25' Bracts, bractlets conspicuous to 0; fruit halves not adhering to central fruit axis |
| |
| | 27. Biennial, perennial herb; leaves 1-pinnate, leaflets lanceolate to ± round; fruit axis entire or merely notched at tip; fruit not conspicuously corky |
| APIUM |
| | 27' Perennial; leaves 1–3-pinnate or 1–3-ternate-pinnate, leaflets mostly lanceolate; fruit axis divided to base; fruit conspicuously corky |
| CICUTA |
| | 19' Plant glabrous or variously hairy, generally not restricted to wet or moist soil of marshes, streambanks, etc or places where water stands for long periods; corolla white, yellow, or purplish |
| |
| | 28. Herbage anise- or licorice-scented; leaf segments thread-like |
| FOENICULUM (no key) |
| | 28' Herbage scented or not, but not anise-scented; leaf segments wider than thread-like |
| |
| | 29. Fruit ribs subequal, none expanded into definite wings |
| |
| | 30. Biennial of disturbed or cultivated places, alien |
| |
| | 31. Stems commonly purple-spotted; cauline leaves like basal; fruit ribs prominent, wavy |
| CONIUM |
| | 31' Stems unspotted; cauline leaves with more, narrower segments than basal; fruit ribs thread-like, not wavy |
| PETROSELINUM (no key) |
| | 30' Perennial of generally undisturbed places, native |
| |
| | 32. Plant dwarfed, 2–15 cm, leaf segments not sharply serrate; montane or alpine |
| |
| | 33. Plant erect or spreading, not cushion-forming, leaves loosely recurved or sometimes spreading at soil surface; umbels not head-like; involucel inconspicuous, not 1-sided, bractlets 0 or free; calyx lobes 0; styles cylindric |
| OROGENIA (no key)2 |
| | 33' Plants cushion-forming or leaves spreading at soil surface; umbels head-like; involucel conspicuous, 1-sided, bractlets generally partly fused; calyx lobes conspicuous; styles very compressed, tape-like |
| |
| | 34. Herbage coarsely hairy to generally tomentose; sterile pedicels many, > fruit |
| OREONANA |
| | 34' Herbage thinly to densely puberulent; sterile pedicels 0–few, < fruit |
| PODISTERA (no key) |
| | 32' Plant not dwarfed, 10–120 cm, if < 20 cm, leaf segments sharply serrate; generally lower than montane or alpine |
| |
| | 35. Fruit linear to oblong, 8–22 mm; fruit oil tubes obscure; roots licorice-scented |
| OSMORHIZA |
| | 35' Fruit oblong to round, 2–9 mm; fruit oil tubes evident, 1–5 per rib-interval; roots not licorice-scented |
| |
| | 36. Corolla white; involucel < or > pedicels or generally 0 |
| LIGUSTICUM |
| | 36' Corolla yellow; involucel present, often > pedicels |
| TAUSCHIA |
| | 29' Fruit ribs unequal, some expanded into definite wings |
| |
| | 37. Ribs at margins of fruit halves winged, others not or more narrowly so; fruit very compressed front-to-back |
| |
| | 38. Plant very robust, 1–3 m; outer petals of marginal flowers > others; oil tubes extending part way to base of fruit |
| HERACLEUM (no key) |
| | 38' Plant not very robust, rarely > 1 m; outer petals of marginal flowers = others; oil tubes extending to base of fruit |
| |
| | 39. Projection atop ovary small, conic, persistent on fruit |
| |
| | 40. Leaf 1–4-pinnately or -ternate-pinnately dissected or compound; corolla white; perennial herb |
| CONIOSELINUM (no key) |
| | 40' Leaf 1–2-pinnate; corolla yellow or orange; perennial herb, generally biennial |
| PASTINACA (no key) |
| | 39' Projection atop ovary 0 |
| |
| | 41. Marginal fruit wings thin or corky, not incurved; fruit axis divided to base |
| LOMATIUM |
| | 41' Marginal fruit wings strongly corky, incurved; fruit axis represented by a corky flange running length of each fruit half along its attachment |
| OROGENIA |
| | 37' Ribs at margins of fruit halves and some others ± winged; fruit cylindric to somewhat compressed front-to-back or side-to-side, rarely very much so |
| |
| | 42. Plant low, generally spreading, stem often 0; rays well developed or not; projection atop ovary 0 |
| |
| | 43. Plant erect or ± spreading; leaf glabrous to scabrous or finely hairy, often glaucous, but lower surface not tomentose; inland — often dry places |
| CYMOPTERUS |
| | 43' Plant prostrate or ± spreading; leaf upper surface green, lower tomentose; seashore |
| GLEHNIA (no key) |
| | 42' Plant erect, stem generally present; rays well developed; projection atop ovary conic |
| |
| | 44. Pedicels reduced to a disk, 2° umbels head-like |
| SPHENOSCIADIUM (no key) |
| | 44' Pedicels distinct or slightly webbed at base but not reduced to a disk, 2° umbels open, not head-like |
| |
| | 45. Stem base not fibrous; leaf segments generally coarse; fruit generally very compressed front-to-back, rarely slightly so or cylindric |
| ANGELICA |
| | 45' Stem base conspicuously fibrous; leaf segments generally fine; fruit compressed side-to-side |
| LIGUSTICUM
|