A N F Keys
1 Corollas all 2-lipped (bilabiate), strap-shaped lips purplish pink to reddish purple or deep lilac (white), 3-toothed (outer lip) and 2-toothed (inner lip) .. Acourtia microcephala [pics]
1' Corollas never 2-lipped or head with inconspicuously 2-lipped ray flowers (Monolopia lanceolata)
2 Plants with milky latex; heads with all flowers having bilateral, ± strap-shaped corolla (ligulate flowers) mostly with 5 short teeth .. GROUP 1
2' Plants lacking milky latex; heads with all flowers ± radially symmetric or having an outer series of bilaterally symmetric flowers (ray flowers)
3 Heads discoid (disc flowers) or disciform (disc flowers and similar peripheral flowers)
4 Pappus absent or minute and inconspicuous .. GROUP 2
4' Pappus present on most or all flowers .. GROUP 3
3' Heads radiate, having an outer series of bilateral ray flowers and a central area of disc flowers
5 Pappus absent or minute and inconspicuous .. GROUP 4
5' Pappus present on most or all flowers
6 Pappus of soft to firm bristles .. GROUP 5
6' Pappus of pointed, barbed awns or stiff scales .. GROUP 6
GROUP 1. Milky latex present; heads composed of only bilateral flowers (ligulate) with 5 teeth
1 Pappus composed of scales, in some cases terminating with stiff, barbed awn (aristate)
2 Perennial herbs; heads subsessile in paniclelike arrays; flowers blue; pappus of minute, awnless scales .. Cichorium intybus [pics]
2' Annuals; heads on long peduncles, solitary and terminal or in cymelike array with several heads; flowers yellow, pale yellow, or white; pappus with conspicuous scales, at least some sharp-tipped
3 Foliage hirsute-hispid becoming ± scabrous with hairs barbed at tip; outer phyllaries bluntly keeled with narrowly winged margins enveloping ovaries becoming incurved and hardened around outer cypselae; pappus of outer flowers with 5 fused scales, of inner flowers not fused .. Hedypnois cretica [pics]
3' Foliage appearing glabrous or mealy from drying of ephemeral hairs; outer phyllaries not hardened and enveloping ovaries or cypselae; pappus scales never united .. Microseris
1' Pappus composed of flexible to stiff bristles, feathery or capillary
4 Pappus bristles mostly feathery with fine lateral branches (plumose)
5 Fruit with prominent beak between cypsela and pappus, at least for central flowers
6 Perennial herbs with grasslike basal and cauline leaves, blades mostly 200+ mm long; heads solitary on long peduncles terminating each shoot, 50−70 mm across; corollas purple; head in fruit ca. 100 mm across, fruit ca. 50 mm long including ribbed cypsela and beak with reddish brown pappus 21−25 mm long .. Tragopogon porrifolius [pics]
6' Annuals with at least some leaves having lobes or teeth; heads in branched array; corollas not purple; head in fruit with pappus < 35 mm across
7 Shoots glabrous; heads 13−24 mm across; corolla white; fruit with cypsela 4−5 mm long and brown with purplish dashes, beak 4.5−7.5 mm long, and pappus 6−8 mm long .. Rafinesquia californica [pics]
7' Shoots with hairs; corolla yellow
8 Plants strongly rosetted, scapose with leafless, branched inflorescences; blades ± hirsute; heads 5−14 mm across; receptacle with bractlets (paleae) < 6 mm long cupped around ovary; outer flowers producing fruits with or without beak, inner fruits beaked .. Hypochaeris
8' Plants with basal and cauline leaves along branched inflorescences; blades bristly with coarse hairs; heads > 20 mm across; receptacle lacking bractlets (paleae); all flowers producing fruits with beak
9 Coarse hairs with 2−4 terminal hooks or grapplelike, lacking fine hairs; blades of basal leaves 100−370 × 25−80(−100) mm; bracts surrounding involucre (calyculus) conspicuous, ovate, 9−20 × 4−9 mm increasing and spreading in fruit; limbs of corollas 10−14 mm long; fruits dimorphic, of outer flowers cypsela enclosed by inner phyllary, crescent-shaped, 2.8−3 mm long, and short-hairy, with beak 4−5 mm long and diminutive pappus 2−3 mm long, of central flowers cypsela mummylike, 2.5−2.8 mm long, with beak 4−5 mm long and pappus 4−7.5 mm long, the beaks slender .. Helminthotheca echioides [pics]
9' Coarse hairs bristlelike to minute-spinelike often hooked or claw-shaped, also with fine curly to wavy hairs; blades of basal leaves 30−100 × 15−55 mm; bracts surrounding involucre (calyculus) absent; fruits ± dimorphic, cypselae compressed oblanceoloid, 3.5−4 mm long and having grasping projections, with beak 8−11(−15) mm long and pappus 9−12 mm long, the beaks greatly enlarged nearly to midpoint and never straight .. Urospermum picroides [pics]
5' Cypselae lacking a beak below pappus; shoots nearly glabrous to white-tomentose or woolly, never stiff hairy; heads on short, axillary cymelike clusters (1-headed) along canopy branches; corolla purple or purplish to pink or lavender (whitish); pappus wholly are partially plumose .. Stephanomeria
4' Pappus bristles mostly of flexible to firm capillary bristles; flowers yellow (white in Malacothrix saxatilis)
10 Fruit having slender beak between cypsela and pappus
11 Plants strongly rosetted and acaulous, with solitary heads on erect peduncles arising from axils of basal leaves; fruit with beak between cypsela and pappus
12 Leaves densely soft-hairy and appearing gray-pubescent; peduncle many-ridged; heads 15−25 mm across; bracts subtending involucre (calyculus) many, ascending and ovate or elliptic, 9−13 mm long; phyllaries 14−24 mm long; head in fruit with pappus 55−65 mm across; cypselae 3.5−7 mm long, 10-pleated, with beak 13−17 mm long and pappus 7−11 mm long .. Agoseris grandiflora var. grandiflora [pics]
12' Leaves villous becoming glabrescent and always appearing green; peduncle smooth; heads 25−50 mm across; bracts subtending involucre (calyculus) 13−19, reflexed and lanceolate, 5−10 mm long; phyllaries 8−18 mm long; head in fruit with pappus 25−35 mm across; cypselae 2.8−3 mm long, with beak 7−9 mm long and pappus 5−7 mm long .. Taraxacum officinale [pics]
11' Plants with basal and cauline leaves, with many heads in canopy
13 Shoots often with prickles or bristles to 3 mm long along stems and leaf axes; inflorescence open, heads 9−11 mm across; bracts subtending involucre (calyculus) ca. 8, ascending and narrowly ovate to triangular to 3 mm long; head in fruit with pappus 11−17 mm across: cypselae 2.8−3.5 mm long and strongly compressed, with beak 3.5−4.1 mm long and pappus 4−5 mm long .. Lactuca serriola [pics]
13' Shoots with smooth, ascending, wandlike photosynthetic branches (virgate); inflorescence of heads densely clustered at axils, with heads 13−17 mm across; bracts subtending involucre (calyculus) several and minute; head in fruit with pappus > 17 mm across; cypselae ± 3 mm long and angular and 15-ribbed, with beak 4.5−5 mm long and pappus (5−)5.5−6 mm long .. Chondrilla juncea [pics]
10' Fruit lacking beak between cypsela and pappus
14 Heads to 26 mm across; flowers yellow
15 Foliage conspicuously villous and with some dendritic hairs and scattered short-stalked glandular hairs, dendritic hairs and glandular hairs also on inflorescence; heads ca. 15 mm across; limbs of corolla ca. 4 mm long .. Hieracium argutum [pics]
15' Foliage never having dendritic hairs
16 Upper cauline leaves slender and linear, with teeth at base or slender clasping basal lobes (auriculate); bracts subtending involucre (calyculus) ca. 8
17 Heads 6.5−8 mm across; peduncles, bracts, and involucres ± glabrous; limbs of corollas 2.2−2.5 mm long cypselae (1.2−)1.4−1.6 mm long, with pappus having outer set of minute triangular scales + a long bristle and an inner set of bristles 4−4.5 mm long .. Malacothrix clevelandii [pics]
17' Heads 16−24 mm across; peduncles, bracts, and involucres short-hairy and with some glandular hairs, the glandular hairs on phyllaries often blackish and aging bristlelike; limbs of corollas 4.5−9 mm long; cypselae 2−2.6 mm long and strongly 10-ribbed, with pappus bristles in 2 series 4−6 mm long .. Crepis capillaris
16' Upper cauline leaves conspicuous, often toothed or lobed, with prominent clasping basal lobes; bracts subtending involucre (calyculus) absent; involucre glabrous or with glandular hairs; pappus 5−9 mm long, for each flower inner series of capillary bristles coherent or fused at base; cypselae 2.5−3.8 mm long .. Sonchus
14' Heads 20−43 mm across; flowers white with some having pinkish midstripe; outer pappus whorl a rim with minute teeth and inner pappus whorl of barbed capillary bristles fused at bases .. Malacothrix saxatilis var. tenuifolia [pics]
GROUP 2. Heads discoid (disc flowers) or disciform (disc flowers and similar peripheral flowers); pappus absent or minute and inconspicuous
1 Flowers of 2 types in each head
2 Peripheral flowers with corolla more showy than on central disc flowers
3 Peripheral flowers bisexual; phyllaries > 25 in 2 series, linear-lanceolate; receptacle lacking long capillary bristles; calyx (pappus) of 4 scales to 1 mm long; corolla to 10 mm long, golden yellow .. Chaenactis glabriuscula var. glabriuscula [pics]
3' Peripheral flowers generally neuter; phyllaries many in a graded series, often spinescent on margins; receptacle having long capillary bristles; calyx (pappus) absent; corolla 10−23 mm long, lavender purple, blue, violet-blue, or light purple (white) .. Centaurea (part)
2' Peripheral flowers not more showy than central disc flowers
4 Within a head, peripheral flowers pistillate and central flowers staminate
5 Short and fine-stemmed annuals with white-woolly foliage; involucre < 3 mm wide
6 Heads with only 7−11 flowers; shoots with mostly alternate leaves
7 Leaves mostly basal; paleae of pistillate flowers 3-veined (having 2 prominent lateral veins); paleae of staminate flowers persistent and hooked at tip .. Ancistrocarphus filagineus [pics]
7' Leaves cauline; paleae of pistillate flowers 1-veined; paleae of staminate flowers lacking paleae and hooks .. Micropus californicus var. californicus [pics]
6' Heads with 14−22 flowers; leaves opposite at nodes 1−2; heads readily separating from plant like minute, cottony balls .. Stylocline gnaphaloides [pics]
5' Rhizomatous perennial herb to 45 cm tall, foliage strigose to villous with gland-dotted leaves and involucres, pleasantly aromatic; involucre at anthesis 3.7−5 mm wide and wider in fruit .. Iva axillaris [pics]
4' Within a head, peripheral flowers pistillate and central flowers bisexual or appearing so; anthers fused into cylinder surrounding style
8 Plants mostly woolly or cottony on at least young foliage (plants often gray to white; exceptions in Pseudognaphalium) and clusters of heads; phyllaries and other bractlets scarious and white to silvery reflective or light pink
9 Receptacle without bractlets (paleae); heads with pistillate peripheral flowers and bisexual central flowers
10 Blades green, at least upper surface, at maturity; foliage strongly scented and obviously glandular-hairy .. Pseudognaphalium (part)
10' Blades white-tomentose to woolly on both surfaces; foliage unscented or only mildly scented and glandular hairs absent or inconspicuous
11 Heads clustered at tips of stems, usually surpassed by subtending leaves; pappus bristles 8−12, not united and falling separately .. Gnaphalium palustre [pics]
11' Heads not so clustered and subtending leaves very reduced or absent; pappus bristles 12+ and united at base and falling as a unit .. Pseudognaphalium (part)
9' Receptacle with bractlets (paleae); shoots with mostly opposite leaves; pistillate peripheral flowers 10−30; paleae veiny; pappus absent .. Psilocarphus tenellus [pics]
8' Plants neither conspicuously woolly nor having scarious bracts on the head
12 Corolla of peripheral flowers absent; central flowers with 4 stamens and a 4-lobed corolla
13 Leaves helically alternate; heads terminal on a conspicuous peduncle; central flowers bisexual; peripheral flowers short-stalked, leaving short pedicles on old receptacle; cypselae often winged .. Cotula
13' Leaves alternate but appearing opposite at each fork produced a sessile, solitary head; central flowers functionally staminate; peripheral flowers sessile; cypselae not winged, horseshoe crab-shaped with a spinelike tip .. Soliva sessilis [pics]
12' Corolla of peripheral flowers present
14 Ephemeral, strongly aromatic annual; peripheral (ray) flowers not showy and enclosed within a phyllary, which falls with the fruit; central flower surrounded by a tube of fused bractlets (paleae) .. Madia exigua [pics]
14' Shrubs, perennial herbs, biennials (annuals); flowers somewhat colorful, peripheral flower not closely associated with a phyllary; bractlets (paleae) absent on receptacle
15 Leaves helically alternate (sometime opposite in Artemisia tridentata) but branching always alternate, foliage strongly scented (unscented in A. biennis); corolla pale yellow to greenish, of peripheral flowers 2−5-lobed, of central flowers 5-lobed .. Artemisia (part)
15' Taprooted annuals; leaves (and branches) opposite decussate, scabrous and strigose; central flowers functionally bisexual; corolla lobes whitish, of peripheral flowers unlobed or shallowly 2-lobed, of central flowers 4(−5)-lobed .. Eclipta prostrata [pics]
1' Flowers only of 1 type in a head
16 Heads unisexual; staminate heads of discoid flowers and anthers not fused; pistillate heads highly modified with pistillate flowers concealed within involucres (except exserted styles); fruits burlike (spinescent involucres) or not but with tubercles, cypsela always hidden within involucre
17 Leaves pinnately lobed; staminate involucre with united phyllaries; fruiting involucre 1-fruited, having a spine or tubercle projection from each phyllary .. Ambrosia
17' Leaves unlobed or with only basal lobes; staminate involucre with phyllaries free; fruiting involucre 2-fruited, covered with many hooked bristles .. Xanthium
16' Heads of bisexual discoid flowers; anthers fused in a ring surrounding style; shrubs with gray to whitish foliage; corolla 5-lobed, yellow; fruiting structures never spinescent
18 Leaves crowded along stems, blades linear to oblanceolate and often shallowly 3-lobed at tip, (2−)8−35(−55) × 1.5−5 mm, strongly aromatic; corolla 0.8−1.2 mm across, pale yellow .. Artemisia tridentata subsp. parishii [pics]
18' Leaves widely spaced, blades linear and never lobed, 20−60 × 1−2.5 mm with dense, white, feltlike hairs, unscented; corolla 5−6 mm across, vivid yellow .. Tetradymia comosa [pics]
NB. Hesperevax has also recently been collected in range.
GROUP 3. Heads discoid (disc flowers) or disciform (disc flowers and similar peripheral flowers); pappus present and relatively conspicuous
1 Flowers of 2 types in each head
2 Peripheral flowers < central flowers, each peripheral flower opposite a phyllary, pistillate, and having a bright yellow, 2-toothed corolla; central disc flowers bisexual and having 4 stamens and mostly 4 corolla lobes; aromatic (sticky), glabrous ephemeral annuals of the coastal zone .. Amblyopappus pusillus [pics]
2' Peripheral flowers > central flowers
3 Blades linear with upper cauline leaves having tiny basal lobes; bisexual central flowers typically with 4 stamens; phyllaries green and striped often with dark purple tips; plants ± white woolly .. Senecio quadridentatus [pics]
3' Blades not lobed; bisexual central flowers typically with 5 stamens; phyllaries not with dark purple tips
4 Relatively unbranched and often tall annuals; leaves conspicuously hairy, where glandular hairs present not in shallow pits; central flowers bisexual; pappus 2−3.7 mm long
5 Shoots villous and viscid with stalked glandular hairs; cauline leaves sessile and clasping; heads with 150−200 peripheral flowers and 8−10 central flowers .. Laënnecia coulteri [pics]
5' Shoots not viscid and lacking glandular hairs; cauline leaves sessile to petiolate but not clasping; heads generally with < 150 peripheral flowers and > 12 central flowers .. Erigeron (part)
4' Rhizomatous perennials (annuals); leaves strongly spicy with glandular hairs in shallow pits; central flowers functionally staminate; corolla with rose-pink to purple lobes, pappus capillary bristles ca. 4.5 mm long .. Pluchea odorata var. odorata [pics]
1' Flowers of 1 type in each head
6 Low, weedy annual with feathery, finely dissected leaves that smell like pineapple; tiny bisexual disc flowers 125−500+ produced on a conic to hemispheric receptacle; corolla 4-lobed and stamens 4 .. Matricaria discoidea [pics]
6' Shrubs to annuals without finely dissected leaves, sometimes aromatic but never scented like pineapple; bisexual disc flowers produced on a flat to concave receptacle; corolla typically 5-lobed and stamens 5
7 Plants with either spine-tipped phyllaries or spines on leaves and internodes or both (thistles)
8 Pappus of white capillary bristles or narrow scales
9 Fruit lacking beak between cypsela and pappus
10 Blades with spine-tipped teeth; flowers monomorphic and all bisexual
11 Stem internodes spinescent along leaflike wings (decurrent leaf bases); corollas 12−16 mm long, with linear lobes 4−5.3 mm long and dark lavender, orchid, or purple; cypselae 3.8−4.2 mm long, with 100−170 bristles to 15 mm long .. Carduus pycnocephalus subsp. pycnocephalus [pics]
11' Stem internodes not spinescent; corolla 20+ mm long
12 Blades broad, to 600 mm long, dark green with wide, gray to whitish areas along principal veins; corollas with 3−4 lobes fused 1/4−1/2 length, dark purple; cypselae 5.5−7 × 3.3−4 mm, with pappus 5−7 whorls of long capillary bristles with inner whorl of shorter, fine hairs, falling together as a cupped ring .. Silybum marianum [pics]
12' Blades oblong to lanceolate, to 120 mm long, green without gray to whitish patches; corolla with all separate lobes, bright yellow with purplish red veins; cypselae 4.5−5 mm long, at least inner fruits of head with 85−105 narrow, white pappus scales .. Carthamus lanatus [pics]
10' Blades lacking spines, to 150 mm long, never dark green and lacking achlorophyllous areas; flowers dimorphic with peripheral flowers somewhat showier and neuter; corollas 10−23 mm long, with lobes not fused, yellow, blue, lavender purple, to light purple; cypselae 2.5−5 mm long .. Centaurea (part)
9' Fruit having beak between cypsela and pappus, beak ca. 0.2 mm long, cypselae never produced from showier, neuter peripheral flowers .. Centaurea calcitrapa [pics]
8' Pappus bristles mostly feathery with fine lateral branches (plumose); fruit lacking beak between cypsela and pappus
13 Both leaves and involucre having sharp spines; blades of cauline leaves mostly toothed or shallowly lobed, lacking glandular hairs; corolla < 25 mm long with lobes < 7 mm long, light to deep purple, lavender, or white; pappus bristle plumose base-to-tip .. Cirsium
13' Leaves spiny but involucre like a pine cone and lacking spines or spines < 2 mm long; blades of cauline leaves deeply pinnately lobed, with midrib appearing to have leafy wings, lower surface with scattered glandular hair beneath wool; corolla 32−54 mm long with lobes 5−12 mm long, blue; pappus bristles finely and short-plumose at least from midpoint .. Cynara cardunculus subsp. cardunculus [pics]
7' Plants lacking spines on shoots and inflorescences
14 Disc flowers yellow
15 Perennial vines with large polygonal blades 20−80 mm wide broadly dentate and having palmate venation .. Delairea odorata [pics]
15' Shrubs or subshrubs or annuals, blades < 35 mm wide
16 Blades linear, threadlike, or scalelike < 5 mm wide and with entire margins
17 Shoots with blades reduced to appressed scales and stem hidden by green, decurrent leaf bases defined by grooves; heads with 9−13(−17) disc flowers; corolla 3−4 mm across; pappus bristles dense, 5−8 mm long, and persistent .. Lepidospartum squamatum [pics]
17' Leaves spreading to ascending from stems
18 Leaves widely spaced, blades 20−60 × 1−2.5 mm with dense, white, feltlike hairs, unscented; heads with (5−)6 flowers; 5−6 mm across .. Tetradymia comosa [pics]
18' Internodes between leaves < 10 mm, blades resinous and aromatic when crushed, either glabrous to glabrate (often coated with resin) or tomentose matted with resin; heads with 4−18 flowers 1.5−3 mm across .. Ericameria (part)
16' Blades wider with teeth or lobes
19 Phyllaries in graded series and overlapping
20 Leaves opposite decussate and stems with longitudinal channels below each node, pinnately 3-foliolate or 5-foliolate; pappus of 2(3) erect, barbed awns .. Bidens (part)
20' Leaves helically alternate, blades never compound, toothed; pappus of capillary bristles
21 Leaves clasping; arrays of heads racemelike to spikelike; involucre ± cylindric, 6.5−12 mm long; corolla throat expanded gradually above tube; cypselae 5.3−7.5 mm long with pappus 8.5−9 mm long .. Hazardia squarrosa var. grindelioides [pics]
21' Leaves sessile to subsessile but not clasping; arrays of heads ± flat-topped to domed; involucre ± cylindric aging inversely conic, 5−10.5 mm long; corolla throat expanded abruptly above tube; cypselae 2−4.2 mm long with pappus to 6.5 mm long and unequal .. Isocoma
19' Phyllaries in 1 or 2 series and appearing whorled, with dark purple or black tips; annuals with lobed, slightly fleshy leaves .. Senecio (part)
14' Disc flowers white or pinkish to purple to greenish or yellowish green, never yellow
22 Herbs
23 Foliage glandular-hairy and aromatic
24 Annuals on burns, foliage resinous-smelling; leaves pinnately compound, 70−180 mm long, much dissected and somewhat 3-dimensional; involucre hemispheric to bell-shaped, 10−12 × 12−15 mm, containing > 150 white flowers .. Chaenactis (part)
24' Annuals (biennials) of moist or coastal habitats, foliage aromatic; leaves pinnately lobed, < 25 mm long; involucre ± hemispheric or ± urn-shaped, 5.5−6 × 6−7.5 mm, containing < 50 golden yellow disc flowers (often also white ray flowers) .. Perityle emoryi [pics]
23' Foliage not glandular-hairy and aromatic; clonal by creeping roots; heads 5−14 mm across, with 11−20+ flowers; corolla 9−11.5 mm long, strong reddish purple; receptacle bristles flattened and smooth, 4−7.5 mm long .. Acroptilon repens [pics]
22' Shrubs or subshrubs
25 Leaves opposite decussate having petioles 10−43 mm long, blades 25−110 × 15−90 mm; inflorescence densely glandular-hairy with glandular heads becoming reddish; corollas white; cypselae with pappus of 5 colorless bristles with upward-pointing barbs .. Ageratina adenophora [pics]
25' Leaves helically alternate with petioles to 10 mm long; inflorescence not glandular-hairy; cypselae with pappus of 15+ capillary bristles
26 Flowers of head appearing bisexual but species dioecious with functionally staminate and pistillate plants, staminate heads with pappus; involucre bell-shaped to hemispheric; staminate flowers 2−2.5 mm across, pistillate flowers 0.25−0.5 mm across; cypselae 5-ribbed, with white (brown) pappus .. Baccharis
26' Flowers all bisexual producing fruits with pappus; involucre cylindric to subcylindric; flowers to 1 mm across; cypselae 10-ribbed, with tawny to straw-colored pappus .. Brickellia
GROUP 4. Heads radiate (ray flowers and disc flowers); pappus absent or minute and inconspicuous
1 Ray flowers white, of material escaped from cultivation of bright colors, never yellow
2 Heads with white ray flowers
3 Corollas of disc flowers white
4 Perennials with helically alternate, finely dissected, aromatic leaves; heads in tight, flat-topped or convex array; limbs of ray flowers roundish, 1.8−2.3 × 1.8−2.1 .. Achillea millefolium [pics]
4' Annuals with opposite decussate, unlobed, scabrous and strigose leaves; heads in open, cymelike array; limbs of ray flowers linear and inconspicuous .. Eclipta prostrata [pics]
3' Corollas of disc flowers ± golden yellow
5 Phyllaries pocketlike, each enclosing a ray flower; receptacle bractlets (paleae) forming a curtain between ray flowers and outer disc flowers; limbs of ray flowers white with purple veins on lower surface .. Hemizonia congesta subsp. luzulifolia
5' Phyllaries not pocketlike and not enclosing a ray flower; receptacle with or without bractlets (paleae), but not having a curtain of paleae between ray flowers and outer disc flowers
6 Limbs of ray flowers roundish, 1.5−4 mm long; pappus of minute scales and rarely 1 short bristle .. Perityle emoryi [pics]
6' Limbs of ray flowers 4−15 mm long
7 Heads in dense, flat-topped arrays; compound leaves with alternate to subopposite lateral leaflets and with a petiole 7−35 mm long .. Tanacetum parthenium [pics]
7' Heads solitary on long axis; compound leaves symmetric with mostly opposite lateral leaflets and lacking a petiole .. Anthemis cotula [pics]
2' Heads with brightly colored ray flowers
8 Leaves opposite decussate, finely 1−3-pinnately dissected; inflorescence a cymelike array of 1−3 flowers; pappus on disc flowers sometimes minutely 1-pointed or 2-pointed .. Cosmos bipinnatus [pics]
8' Leaves helically alternate, simple often shallowly lobed or toothed; heads mostly solitary on long stalks; pappus always absent .. Dimorphotheca
1' Ray flowers yellow, sometimes with white patches
9 Leaves opposite, at least at many of the nodes
10 Blades glaucous and comparatively thick with only a midvein apparent; pappus of disc flowers sometimes of 1−5 bristles < 0.3 mm long; perennial herbs growing in salt marsh .. Jaumea carnosa [pics]
10' Blades neither glaucous nor thick; pappus never of short bristles; plants absent from salt marsh
11 Plants densely woolly; heads 13−45 mm across, ray flowers 5 or 8 and disc flowers 12−many; corolla of ray flower with a small lobe opposite the toothed limb .. Monolopia lanceolata [pics]
11' Plants not woolly; ray flowers 5−13; corolla without special lobe opposite the toothed limb
12 Heads 8−11 mm across, with 5 ray flowers and 6 disc flowers; receptacle with bractlets (paleae) fused for 1 mm to form a short, pleated tube between the 2 types of flowers .. Lagophylla ramosissima [pics]
12' Heads 23−30 mm across, with 6−13 ray flowers and 20−95 disc flowers; receptacle without bractlets (paleae) .. Lasthenia (part)
9' Leaves helically alternate (some opposite, especially on the lower plant)
13 Ray flowers 2-colored with yellow and white, on some or all individuals in a population
14 Robust annuals with 2(−3)-dissected leaves; heads mostly 30−60 mm across with ca. 18 ray flowers and many disc flowers; plants with either all-yellow ray flowers or limbs of ray flowers white at the base and yellow above midpoint; cypselae polymorphic, with various wings .. Glebionis coronaria [pics]
14' Annuals with linear to oblanceolate-linear leaves; heads mostly < 30 mm across with 8−10 ray flowers and 40−48 disc flowers; limbs of ray flowers bright yellow but abruptly white on tips of lobes; cypselae club-shaped and without wings .. Layia platyglossa [pics]
13' Ray flowers only yellow
15 Receptacle without bractlets (paleae)
16 Shrubs of chaparral and coastal sage scrub communities; leaves entire
17 Involucre with leafy, spreading to reflexed phyllaries; corollas of disc flowers bright yellow .. Venegasia carpesioides [pics]
17' Involucre with appressed phyllaries; corollas of disc flowers orange-yellow or dark purple .. Encelia
16' Herbs; woolly tomentose throughout; leaves pinnately lobed with to 3 lobes on each side .. Baileya multiradiata [pics]
15' Receptacle with bractlets (paleae); phyllaries in 1 series, and a phyllary enclosing each ray flower
18 Plants spinescent; involucre subtended by spine-tipped bracts (calyculus); phyllary of ray flower folded lengthwise; disc flowers functionally staminate, each enclosed by a palea .. Centromadia pungens subsp. pungens [pics]
18' Plants not spinescent; involucre not subtended by spine-tipped bracts; disc flowers bisexual or staminate, phyllary of ray flower pocketlike and enclosing ovary of a ray flower; paleae forming a division between ray flowers and outer disc flowers .. Madia (part)
GROUP 5. Heads radiate (ray flowers and disc flowers); pappus of soft to firm bristles
(In Progress)
1 Limbs of ray flowers lavender to shades of purple, violet (bluish), pink, and white
2 Plants mostly woolly (grayish); disc flowers 1.5 mm across; pappus bristles many, 4−6 mm long .. Corethrogyne filaginifolia [pics]
2' Plants nearly glabrous to sparsely short-hairy; disc flowers 0.7−1 mm across; pappus bristles 2−3.8 mm long
3 Blades 1−3 mm wide; heads 15−25 mm across; pappus dimorphic including short scales in an outer whorl .. Erigeron (part)
3' Blades 2−15 mm wide, heads either < or > 15−25 mm across; pappus monomorphic and lacking scales .. Symphyotrichum
1' Limbs of ray flowers yellow (may include some white) to yellow-orange
4 Leaves exclusively opposite decussate, blades glaucous and comparatively thick with only a midvein apparent; pappus on ray flowers absent and on disc flowers either absent or of 1−5 bristles < 0.3 mm long; ray flowers 7−10(−12) and disc flowers (20−)35−50, heads 8−15 mm across; perennial herbs growing in salt marsh .. Jaumea carnosa [pics]
4' Leaves either helically alternate or parts of the shoot with some leaves opposite, blades not conspicuously glaucous or thick; plants absent from salt marsh (sometimes present in coastal sand habitat)
5 Annuals; ray flowers 8−10 and disc flowers 40−48, heads 14−25(−35) mm across; limbs of ray flowers bright yellow but abruptly white on tips of lobes; pappus often absent or reduced to a small crown on top of ovary, but in range disc flowers with 15+ flattened bristles 1−2.3 mm long; inflorescence with glandular hairs having ruby red heads .. Layia platyglossa [pics]
5' Limbs of yellow ray flowers lacking white tips; pappus of disc flowers not of flattened bristles
6 Pappus of 100+ white, soft, silky capillary bristles on cypsela
7 Cauline leaves with basal lobes mostly clasping stem (Note: there is no 7' at this time)
8 Shrubs having leaves pinnately dissected with 1−3 pairs of linear lateral lobes; foliage when young grayish woolly-tomentose; heads with 7−13(−21) ray flowers and 40−63 disc flowers, heads 25−40 mm across .. Senecio (part)
8' Herbs
9 Perennial herbs with long-petiolate lobed lower leaves having a large terminal lobe; ray flowers (4−)6−8 and disc flowers 24−46, heads 12−30 mm across; corolla limbs of ray flowers yellow-orange with darker veins; pappus of capillary bristles 4.5−6.2 mm long in fruit .. Packera breweri [pics]
9' Annuals with mostly shallowly lobed leaves; ray flowers several and inconspicuous to 13 and disc flowers many, heads 3−20 mm across; corolla limbs yellow .. Senecio (part)
6' Pappus of firm capillary bristles on cypsela
10 Shoots gland-dotted and aromatic when crushed
11 Ephemeral annuals to 30 cm tall; heads with 5−8 nonshowy ray flowers and usually 1 disc flower, and each ray flower enveloped by a phyllary; ray flowers separated from disc flower by a tube formed from fused bractlets (paleae); cypselae of disc flowers sometimes having several short bristles .. Madia (part)
11' Perennials; ray flowers neither enveloped by phyllaries nor separated from disc flowers by bractlets (paleae)
12 Perennial herbs with rhizomes
13 Tall, erect shoots in wet soil along creek beds or in wetlands, to 200+ cm tall with linear blades; foliage glabrous; inflorescences congested at shoot tips domelike; heads 3.5−4.5 mm across; pappus capillary bristles 20−40, 3.5−4 mm long increasing to 6 mm long in fruit .. Euthamia occidentalis [pics]
13' Plants of woodland edges, to 150 cm tall, with elliptic to obovate or oblanceolate blades; foliage densely canescent or short-tomentose to nearly glabrous; heads in narrow, paniclelike arrays with heads oriented to the upper side and 3−7 mm across; pappus capillary bristles on cypselae 2.5−3.5 mm long .. Solidago
12' Shrubs with linear leaves, often with resin drying on surface, glabrous to sparsely hairy; ray flowers conspicuous to inconspicuous; pappus bristles 30−50+, 4−8 mm long in fruit .. Ericameria
10' Shoots not gland-dotted or aromatic
14 Coarsely hairy annuals; pappus consisting of an outer whorl of 20−30 scales and 1−2 inner whorls of capillary bristles .. Heterotheca
14' Sparsely hairy annuals; pappus lacking outer whorl of scales; capillary bristles 8−12 united at base, easily broken in fruit but persisting as a ring .. Pentachaeta lyonii [pics]
GROUP 6. Heads radiate (ray flowers and disc flowers); pappus of pointed, barbed awns or stiff scales
1 Pappus awns present on some or all cypselae
2 Foliage covered with soft hairs, densely sericeous-strigose when appressed; heads 30−52 mm across with 12−16 ray flowers and 100+ disc flowers; cypselae of disc flowers with 2 ascending awns 0.7−1.3 mm long but lacking barbs .. Verbesina encelioides [pics]
2' Foliage not covered with soft hairs; ray flowers typically < 11; cypselae with variable numbers of awns
3 Leaves helically alternate; especially heads covered with liquid resin; heads with 20−45 ray flowers; pappus awns on ray flowers 1−2, 3−3.5 mm long; pappus awns on disc flowers 2−3(−6), 3−5 mm long .. Grindelia camporum [pics]
3' Leaves opposite decussate; resin not present on surface of plant; heads with (0)5−13 ray flowers
4 Spring annuals mostly 6−35 cm tall with showy yellow heads (highly variable in size within a population); limbs of ray flowers 1.5−3 mm wide; pappus awns 0−7 on ray flowers and 0−9 on disc flowers, 1−2 mm long, white .. Lasthenia (part)
4' Robust herbs and weeds to 180 cm tall; limbs of ray flower 3−13 mm wide, yellow or white; pappus awns 2−4(−5), 0.5−4 mm long, brown .. Bidens (part)
1' Pappus of translucent, scarious scales on some or all cypselae
5 Coarsely hairy annuals; pappus consisting of an outer whorl of 20−30 scales and 1−2 inner whorls of capillary bristles .. Heterotheca (part)
5' Pappus not composed of separate whorls of scales and bristles
6 Pappus scales on ray and disc flowers 5−6, 0.4−1.2 mm long, the longest ones having a short awn at the top; inflorescence a complete ball of 500−600 disc flowers + 4−20 ray flowers .. Helenium puberulum [pics]
6' Pappus scales with no awns at the top
7 Escaped cultivated herbs with large, multicolored heads, including yellows, white, dark green, and purple; sap milky; pappus on disc flowers only, of 25 silky, erect scales in 2 series and to 7.5 mm long .. Gazania linearis [pics]
7' Herbs, shrubs, and subshrubs with only 1 color of ray flowers per head; sap not milky; pappus not of silky, erect scales
8 Ray flowers white; foliage aromatic
9 Leaves 1−2-pinnately dissected, 30−100 mm long; heads in flat-topped arrays; pappus of ray and disc flowers an irregular crown of short scales 0.1−0.2 mm long .. Tanacetum parthenium [pics]
9' Leaves pinnately lobed, < 25 mm long; heads in cymelike arrays; pappus scales minute and rarely with 1 bristle .. Perityle emoryi [pics]
8' Ray flowers yellow
10 Receptacle without bractlets (paleae) subtending flowers; pappus scales 5−14 in 1−2 series
11 Pappus scales only 0.15−0.3 mm long; disc flowers having 4 stamens and mostly 4 corolla lobes; ray flower inconspicuously bilateral .. Amblyopappus pusillus [pics]
11' Pappus scales 0.4−1.1 mm long; disc flowers having 5 stamens and 5 corolla lobes; ray flowers conspicuously bilateral
12 Subshrub with linear to threadlike leaves, minutely short-hairy, aromatic, and somewhat resinous; ray flowers 4−8 and disc flowers 4−10; projections on receptacle with swollen-base hairs .. Gutierrezia californica [pics]
12' Subshrubs and herbs white-woolly to tomentose and minutely glandular-hairy .. Eriophyllum
10' Receptacle with bractlets (paleae) subtending flowers 4−15 mm long
13 Involucre 8+ mm wide; ray flowers 4−15+ mm wide; palea associated with each flower
14 Pappus scales 2−5, 1.5−4.5 mm long .. Helianthus
14' Pappus scales sometimes found on disc flowers, 1.8−2.2 mm long .. Leptosyne (part)
13' Involucre 2−8 mm wide; ray flowers 2−6.4 mm wide; paleae formed as a curtain between ray flowers and outer disc flowers; pappus scale on disc flowers
15 Pappus scales 5−12 in 1 whorl, 1−2.5 mm long .. Deinandra
15' Pappus scales 10 in 2 whorls (scarious rings), at anthesis ± 2.5 mm long; on mature head, pappus conspicuous and shiny white, outer scales 5.5−6.5 × 2−2.5 mm and inner scales 8−10.5 × 2−2.5 mm .. Achyrachaena mollis [pics]
The text of the above keys used with permission from
A Naturalist's Flora of the Santa Monica Mountains and Simi Hills, California
© Copyright
Barry A. Prigge and Arthur C. Gibson
2013