Distinguishing Characteristics of Similar Species

FAMNameDistinguishing Characteristics
PTECheilanthes covilleileaf margin recurved; leaf surface beady on top, scaly on bottom
PTECheilanthes parryileaf margin recurved; leaf grayish on top, woolly on bottom
PTECheilanthes viscidaleaf margin recurved; leaf sticky on top
PTENotholaena californicaleaf margin recurved; leaf bottom with white exudate
PTEPentagramma triangularis ssp. maxoniileaf margin flat; leaf bottom with white exudate; leaf top with yellow stalked glands
PTEPentagramma triangularis ssp. triangularisleaf margin flat; leaf bottom with yellow exudate; leaf top glabrous
SELSelaginella eremophiladistinguished from moss by presence of roots
EPHEphedra aspera2 leaves / node; seed 1 / cone, surface smooth
EPHEphedra californica3 leaves / node, twigs not spiny
EPHEphedra fasciculata var. clokeyi2 leaves / node; seed 1 / cone, surface furrowed
EPHEphedra nevadensis2 leaves / node; seeds 2 / cone; cone stalked 1-5 mm
EPHEphedra trifurca3 leaves / node, twigs spiny
EPHEphedra viridis2 leaves / node; seeds 2 / cone; cone sessile or stalked 1-5 mm
ACACarlowrightia arizonicaSimilar to Ditaxis lanceolata in gestalt, but leaves opposite
ASCAsclepias albicansfew-stemmed; 6-12 feet high; lvs 2-3 / node; hoods < anther head
ASCAsclepias subulatamany-stemmed; 3-6 feet high; lvs 2 / node; hoods >> anther head
ASCMatelea parvifoliafilament column appendages fused into low structure around anther head
ASCSarcostemma cynanchoides ssp. hartwegiipl sparsely hairy; corolla gen purple; filament column appendages free from ring of tissues at corolla base
ASCSarcostemma hirtellumpl densely hairy; corolla gen greenish white; filament column appendages fused to ring of tissues at corolla base
ASTAdenophyllum porophylloidessomewhat similar to Porophyllum gracile, but lobed leaves with glands and often with sharp teeth
ASTBaccharis sergiloidesSimilar to B. sarothroides, but pistillate pappus very short, 1-3 mm in fr; and larger lvs obovate. B. sarothroides has pappus 7-11 mm, and larger lvs linear
ASTBaileya multiradiata var. multiradiatarays 15-many, bright yellow; invol 10+ mm diam; heads 1; ligules 10-20 mm, widely linear or oblong, prominently 3-lobed; peduncles gen 10-20+ cm, ~scape-like
ASTBaileya pauciradiatarays 4-8, pale yellow; invol gen 4-6 mm diam; heads 2-3
ASTBaileya pleniradiatarays 15-many, bright yellow; invol 10+ mm diam; heads 1; ligules 6-10 mm, widely elliptic to obovate, shallowly 3-lobed to truncate; peduncles gen 3-10 cm, gen leafy-bracted
ASTBrickellia arguta var. argutalvs sharply toothed
ASTBrickellia desertorumpl 8-15 dm; lvs ovate; heads 8-12 fl'd, 8-10 mm; minutely tomentose
ASTBrickellia frutescenspl 3-6 dm; lvs oblong to spoon-shaped; heads 20-30 fl'd, 13-15 mm, gen 1(3), terminal
ASTCalycoseris parryiligules yellow; tack-shaped glands dark-colored
ASTCalycoseris wrightiiligules white; tack-shaped glands pale
ASTChaenactis artemisiifolialower sts and lvs whitish granular-puberulent; largest lf blades (2)3-4 pinnately lobed, longest lobe near base; tips of longest phyllaries sharp but not acuminate, ~flat, green; lf tips flat; pappus 0
ASTChaenactis carphoclinia var. carphocliniacorolla white; tips of longest phyllaries acuminate, needle-like, cylindric, gen reddish;largest lf blades (2)3-4 pinnately lobed, longest lobe near base, bases of petioles not strongly enlarged; lvs basal and cauline, < 7 cm; bases of petioles not strongly enlarged
ASTChaenactis carphoclinia var. peirsoniicorolla white; tips of longest phyllaries acuminate, needle-like, cylindric, gen reddish;largest lf blades (2)3-4 pinnately lobed, longest lobe near base, bases of petioles not strongly enlarged; lvs gen basal, longest 7-10 cm; bases of petioles strongly enlarged; RARE, east base of SnRsMtns
ASTChaenactis fremontiicorolla white; outer phyllaries sharp, becoming glabrous;lvs entire or 1-pinnately lobed, lobes 1-2(5) pairs, well-separated, longest lobe gen near middle
ASTChaenactis glabriuscula var. glabriusculacorolla yellow
ASTChaenactis stevioidescorolla white; outer phyllaries gen blunt, persistently glandular-hairy or cobwebby; largest lf blades entire or 1-2 pinnately lobed, longest lobe gen near middle
ASTChaenactis xantianalower sts and lvs glabrous or +-cobwebby; largest lf blades entire or 1-2 pinnately lobed, longest lobe gen near middle; corolla white, longest phyllaries 10-18 mm, bases glabrous, tips densely puberulent; corollas radial; peduncles not glandular
ASTChrysothamnus paniculatuslike Ericamera brachylepis, but phyllaries ~ 5 ranked in columns, midvein not prominently raised
ASTChrysothamnus teretifoliusherbage gland-dotted; corollas yellow; phyllaries strongly vertically ranked, tips swollen, green
AST*Conyza bonariensismidvein of phyllary green to purple, not resin-filled; ligules ~ 0 mm
ASTConyza canadensismidvein of phyllary brown, resin-filled; ligules 0-1 mm
ASTEncelia actoniheads solitary; rays present
ASTEncelia farinosaheads in panicles; dead heads nodding, minute
ASTEncelia frutescensheads solitary; rays absent
ASTEricameria brachylepislvs thread-like; heads in raceme-like or narrowly panicle-like clusters at ends of leafy branches
ASTEricameria cuneata var. spathulatalvs obovate, 4-16 mm wide
ASTEricameria linearifolialvs linear; head 1 per stem
ASTEriophyllum multicauleheads ~ sessile, peduncle < 5 mm; ray fls 5-7, ligules ~ 2 mm, yellow
ASTEriophyllum wallaceipeduncle 1-3 cm; ray fls 5-10, ligules 3-4 mm, yellow to cream-white
ASTFilago arizonicasts spreading, heads in groups of 4-10, restricted to forks and tips of branches; sts gen lfless between lower forks, ~glabrous, purplish to black
ASTFilago californicasts ~erect, not forked, central axis dominant; heads in groups of 1-4, not restricted to forks and branch tips; sts ~evenly leafy between lower forks, cobwebby, grayish to greenish; lvs gen oblanceolate, acute
ASTFilago depressasts ~spreading, forked, central axis not dominant; heads in groups of 1-4, not restricted to forks and branch tips; sts ~evenly leafy between lower forks, cobwebby, grayish to greenish; lvs gen elliptic to obovate, obtuse
ASTGeraea canescenslvs wing-petioled below, invol 7-12 mm; phyllaries narrowly lanceolate, acute, green ciliate; ray fls 10-21, ligules 1-2 cm
ASTHelianthus niveus ssp. canescenscentral chaff scales tipped with stiff white hairs
ASTHelianthus niveus ssp. tephrodessand dunes; central chaff scales glabrous or very finely appressed-hairy
ASTIsocoma acradenia var. acradenialvs narrowly lanceolate, entire; invols 4-5 mm
ASTIsocoma acradenia var. eremophilalvs narrowly obovate, with long-tapering base, to oboate, with 4-6 teeth per side; invols 5-7 mm
ASTMalacothrix californicast scapose; lvs gen long-hairy near base
ASTMalacothrix glabratasts leafy, ~branched; basal lvs not long-hairy at base
ASTPectis papposa var. papposaherbage spicy-scented; mound-shaped; lvs narrowly linear, gland-dotted on margins; phyllaries 8, linear, each with subterminal gland and several smaller submarginal glands; rays 8; corollas 3-6 mm
ASTPorophyllum gracileSomewhat similar to Adenophyllum porophylloides, but lvs entire, linear, glaucous
ASTRafinesquia californicaligules 5-8 mm, 3-5 mm beyond phyllaries
ASTRafinesquia neomexicanaligules 15-20 mm, 10+mm beyond phyllaries
AST*Sonchus asper ssp. asperbasal lobes of lvs rounded
AST*Sonchus oleraceusbasal lobes of lvs acute
ASTStephanomeria exigua ssp. deaneipeduncles and invols strongly glandular; frs 2-2.5 mm
ASTStephanomeria exigua ssp. exiguapeduncles and invols glabrous to sparsely glandular; frs 2.6-3.2 mm
ASTStylocline gnaphaloideslvs gen obtuse, uppermost < 13 mm, ~elliptic to obovate
ASTStylocline micropoideslvs acute, uppermost gen 11-15 mm, awl-like to lanceolate
ASTTrichoptilium incisumgen tomentose or white-woolly; lvs mostly clustered in lower half, 1-3 cm; heads discoid, solitary; phyllaries in 2 ~equal series, free, 5-7 mm; pappus of 5 scales, each 5-7 mm, dissected into many bristles
ASTViguiera parishiipappus of 2 fringed scales (each 0.5-1.5 mm) and 2-3 lanceolate scales (each 2-3 mm)
BORAmsinckia menziesii var. intermediacalyx lobes 5; corolla tube 10 veined near base; nutlet surface tubercled, sometimes ridged; corolla 7-11 mm, 4-10 mm wide at top
BORAmsinckia menziesii var. menziesiicalyx lobes 5; corolla tube 10 veined near base; nutlet surface tubercled, sometimes ridged; corolla 4-7 mm, 2-3 mm wide at top
BORAmsinckia tessellata var. tessellatacalyx lobes 2-4; corolla tube 20 veined near base; nutlet surface cobblestone-like or round-tubercled, ridged or not; corolla 8-12 mm, 2-6 mm wide at top
BORCryptantha angustifoliacorolla width 1-5 mm; calyx 1-3.6 mm in fl, 2.5-4 mm in fr; nutlets 4
BORCryptantha barbigeracorolla width 1-8 mm; calyx 4-6 mm in fl, 5-10 mm in fr; nutlets 1-4
BORCryptantha costatanutlets 4, sharp-angled; calyx in fl 3-4 mm
BORCryptantha decipienslike C. holoptera, but with spikes mostly in 2's; corolla width 1-5 mm; calyx 1.5-2.5 mm in fl, 2-4 mm in fr; nutlets 1-2
BORCryptantha gandericorolla width 1-2 mm; calyx 3-4 mm in fl, 6-10 mm in fr; nutlets 1-2
BORCryptantha holopteralike C. decipiens, but with numerous short ascending branches; nutlets winged < 0.5 mm, wings not lobed
BORCryptantha intermediacorolla width 2-8 mm; calyx 2-3.2 mm in fl, 3.5-6 mm in fr; nutlets 1-4
BORCryptantha maritimacorolla width 0.5-1.5 mm; calyx 1-2 mm in fl, 2-3.1 mm in fr; nutlets 1-2
BORCryptantha micranthaPlant gen wider than tall; flowers in dense bracted heads; calyx not circumscissile; root purplish
BORCryptantha muricatacorolla width 1-8 mm; calyx 1-2 mm in fl, 2-4.2 mm in fr; nutlets 4(2-4)
BORCryptantha nevadensiscorolla width 1-2 mm; calyx 1.8-4 mm in fl, 4-10 mm in fr; nutlets 4
BORCryptantha pterocaryanutlets winged 0.5-1.0 mm, wings lobed
BORCryptantha pterocarya var. cyclopteraPlant tall, upright; flower appears to float out of a honking calyx, due to the wings on the nutlets
BORCryptantha racemosaperennial
CHEAtriplex canescens ssp. canescensshrub; fruit 4 winged, 4-25 mm
CHEAtriplex lentiformis ssp. lentiformisshrub; fr unwinged, 2-6 mm; lvs entire, ovate to deltate, gen 10-50 mm wide
CHEAtriplex polycarpashrub; fr unwinged, 2-3 mm; lvs entire, oblong, 2-4 mm wide
FABAmorpha fruticosano glands on leaf rachis
FABAstragalus crotalariaeleaves green
HYDPhacelia crenulata var. ambigualike P. pedicellata, but with gray / yellow pollen, and pedicels shorter than calyx
HYDPhacelia crenulata var. minutifloralike P. pedicellata, but with gray / yellow pollen, and pedicels shorter than calyx
HYDPhacelia pedicellatalike P. crenulata, but with blue/purple pollen and pedicels at least as long as calyx
KRAKrameria erectaspines barbed along shaft or smooth; flag petals fused at base
KRAKrameria grayispines barbed only at tip; flag petals free
LOAMentzelia affinisfruit 1 rowed above mid-ovary; seeds prism-like, 3 angled
LOAMentzelia albicaulisfruit 2-3 rowed above mid-ovary; seeds grain-like
RHAZiziphus parryi var. parryiSimilar in habit to Prunus fremontii, but leaf elliptic to obovate, margin ~entire; fr glabrous; petals yellow
ROSPrunus fremontiiSimilar in habit to Ziziphus parryi, but leaf ovate to round, crenulate to serrate (you "prunus with a saw"), fruit puberulent; petals white
TYPTypha domingensispistillate stalks peg-like, not hair-like
http://tchester.org/bd/species/similar_species.html
Updated 20 November 2009.