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1 Principal leaves either all simple (though sometimes palmately or pinnately lobed) or those that are basally disposed simple (those on the upper stem sometimes compound) | |
1 Principal leaves all variously compound (small bracteal leaves on the upper stem sometimes reduced and simple). | |
2 Leaves 1-palmately or 1-pinnately compound (all leaflets attached to the summit of the petiole or to the primary inflorescence rachis). | |
2 Leaves 2-5× compound, with 5-200+ leaf divisions, at least some attached to secondary or higher-order inflorescence axes. | |
4 Leaves 2-4× pinnately or pinnately-ternately compound, the ultimate segments consisting of relatively few (usually < 25), discreet, typically broad (elliptic, ovate, or lanceolate) leaflets. | |
4 Leaves 2-5× pinnately or pinnately-ternately decompound, the ultimate segments either linear and < 1 mm wide (and then either flat or angled in ×-section) or broader than 1 mm wide, but if broader then many (> 25) and often imperfectly separated from one another. | |
5 Leaves 2-5× pinnately or pinnately-ternately decompound, the ultimate segments linear and < 1 mm wide (and then either flat or angled in ×-section) | |
5 Leaves 2-5× pinnately or pinnately-ternately decompound, the ultimate segments broader than 1 mm wide, but if broader then many (> 25) and often imperfectly separated from one another | |
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2 Leaves phyllodial (septate, hollow or flat, segmented); flowers white or purple; [plants of wetlands]. | |
3 Umbels compound; leaves tapering to a pointed tip, either flat or terete in ×-section. | |
4 Leaves flat in ×-section, with obvious parallel venation and less obvious septae / cross-partitions | |
4 Leaves terete in ×-section, the septae obvious. | |
5 Plants 1-11 dm tall, annuals, sometimes mat-forming and adventitiously perennial; fruits 1-3 mm long, with lateral ribs; rays 3-15 | |
5 Plants 6-24 dm tall, perennials from rhizomes or tubers; fruits 4-9 mm long, with lateral wings; rays 5-20 | |
2 Leaves “normal” (non-septate, flat, continuous, and in some cases lobed, toothed, or spinose-margined); flowers blue, yellow, white, or whitish-green; [plants of wetlands or uplands]. | |
6 Flowers in compound umbels; corolla yellow or white. | |
9 Leaves herbaceous or somewhat fleshy. toothed or lobed, but not spinose; inflorescence umbellate or verticillate; flowers white, greenish, or purplish; [collectively common and widespread]. | |
11 Leaves perfoliate; flowers yellow; [rare exotics]. | |
13 Flowers greenish or blue; leaves all simple (sometimes stem leaves lobed); inflorescence a head or very congested (subcapitate) umbel; [plants of wetland situations, prostrate, creeping, or erect]. | |
14 Inflorescence a very congested (subcapitate) umbel, with 4-9 flowers; leaves cordate at the base, long-petiolate, the petioles characteristically 2× as long as the leaf | |
13 Flowers yellow or purple; basal leaves simple, stem leaves usually compound; Inflorescence a compound umbel; [erect plants of upland situations]. | |
15 Fruits ribbed (with rounded, cordlike ribs), lacking thin-edged wings; flowers yellow; central flower of each umbellet either staminate and pedicelled, or pistillate and sessile; fruits all pedicelled in some umbellets (those with a staminate central flower), or the central fruit sessile in some umbellets (those with a pistillate central flower) |
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1 Leaflets narrowly lanceolate or linear, > 8× as long as wide, entire; umbels compound and regular, the rays and pedicels each of relatively uniform lengths; leaves 3-5-foliolate. | |
2 Fruit 2-3 mm long; leaves 1-5-foliolate; [of calcareous or rich moist to wet areas, AL and TN and westward] | |
2 Fruit 3-5 mm long; leaves 1-3-foliolate; [of saturated acid wetlands, of the FL Panhandle, e. GA, e. SC, e. NC, and e. VA] | |
1 Leaflets ovate, obovate, broadly lanceolate, or broadly oblanceolate, 1-5× as long as wide, serrate or variously incised or cleft; umbels compound and irregular, the rays and/or pedicels of widely varying lengths; leaves 3-7-foliolate. | |
3 Rays 3-8, the involucre absent or inconspicuous; umbellets with 3-10 pedicellate perfect flowers; fruits linear-oblong, glabrous; leaves 3-foliolate, the lateral leaflets often 2-parted; corollas white | |
3 Rays few, the involucre of prominent, broad, foliaceous bracts; umbellets with 3 sessile to subsessile or short-pedicellate perfect flowers and a variable number of pedicellate staminate flowers; fruits ovoid, obovoid, or subglobose, covered with uncinate bristles; leaves palmately 3-7-foliolate, the lateral sometimes 2-parted; corollas greenish-white, yellowish-green, or white |
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1 Larger leaves 20-50 cm wide, 3 (-5) foliolate, many of the leaflets deeply lobed into segments often > 10 cm wide; fruits 8-15 mm long, pubescent; petioles sheathing and also strongly dilated | |
1 Larger leaves 3-25 cm wide, 5-15 (or more) foliolate, the leaflets variously toothed, if also deeply lobed, the segments < 3 cm wide; fruits 1-7 mm wide; petioles sheathing, not dilated. | |
3 Leaflets rather finely toothed (and sometimes also deeply lobed), the teeth evenly disposed along the margins; fruits 1-6 mm long; corolla white or yellow. | |
6 Bracteoles present subtending the umbellets; outer flowers of the umbellet asymmetric, with the outer petals larger and often bifid (raylike); annuals; stems solid | |
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1 Leaflets entire. | |
4 Corolla yellow, maroon, or pale creamy yellow. | |
5 Flowers yellow, maroon, or pale creamy-yellow; central flower of each umbellet staminate and pedicelled; fruits all pedicelled in all umbellets; developing fruits subterete to slightly dorsally compressed, several or all of the ribs with thin-edged wings | |
5 Flowers yellow; central flower of each umbellet either staminate and pedicelled, or pistillate and sessile; fruits all pedicelled in some umbellets (those with a staminate central flower), or the central fruit sessile in some umbellets (those with a pistillate central flower); developing fruits laterally compressed, all of the ribs rounded and cordlike | |
4 Corolla white. {Add to keylead 4b: Apium graveolens var. dulce, Cicuta bolanderi, Cicuta mexicana, Imperatoria ostruthium, Petroselinum crispum} | |
7 Rays 16-25; leaves somewhat coriaceous; leaflet bases often cuneate or obliquely truncate; [plants of dry habitats] | |
11 Sheaths of the upper leaves not dilated, < 1 cm wide; [plants either of wetlands or of moist to dry forests]. | |
15 Fruits dorsally compressed (strongly to slightly) or subterete, either thin-winged or corky-winged. | |
16 Ribs thin-winged; fruits 3-8 mm long; [common natives of most to submesic forests]. | |
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1 Corolla yellow; rays 15-40; plants 5-21 dm tall; fruits ca. 2× as long as wide; [naturalized aromatic culinary herbs of upland situations]. | |
3 Mericarps (and ovary) ornamented with tubercles, spines, or sharp-pointed projections ("scabes"), in addition to the ribs (use at least 10× magnification). | |
4 Schizocarp ovoid-oblong to urceolate-ovoid or broadly ellipsoid, ribs sparsely to densely scaberulous with single-celled papilla-like projections | |
4 Schizocarp broadly ovoid to ellipsoid or elliptic-ovoid, ribs and intervals variously hairy or at least tuberculate | |
5 Umbels terminal or on axillary branches; umbels compound. | |
9 Umbellets per umbel (=rays) 2-30; [collectively widespread and common]. | |
10 Non-sheathing portion of petioles 5-10 cm long. | |
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1 Plants perennial or biennial, 3-30 dm tall; rays 12-60. | |
2 Fruits 2-6 mm long, 1.7-3.5 mm broad; corollas white; [either native, NY, NJ, PA, w. VA, w. NC, and s. IN northward, or exotic and widespread]. | |
3 Fruits 2-2.5 mm long; plant from a thickened taproot; [collectively common plant of mostly disturbed areas] | |
4 Plants annual (or sometimes a short-lived perennial in Anthriscus) from fibrous roots; flowering Apr-Jun; [of rich forests or weedy situations]. | |