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Theodore M. Barkley+, Luc Brouillet, John L. Strother in Flora of North America (vol. 19, 20 and 21)
Annuals, biennials, perennials, subshrubs, shrubs, vines, or trees. Roots usually taproots, sometimes fibrous. Stems usually erect, sometimes prostrate to ascending (underground stems sometimes woody caudices or rhizomes, sometimes fleshy). Leaves usually alternate or opposite, sometimes in basal rosettes, rarely in whorls; rarely stipulate, usually petiolate, sometimes sessile, sometimes with bases decurrent onto stems; blades usually simple (margins sometimes 1-2+ times pinnatifid or palmatifid), rarely compound. Inflorescences indeterminate heads (also called capitula); each head usually comprising a surrounding involucre of phyllaries (involucral bracts), a receptacle, and (1-)5-300+ florets; individual heads sessile or each borne on a peduncle; heads borne singly or in usually determinate, rarely indeterminate, arrays (cymiform, corymbiform, racemiform, spiciform, etc.); involucres sometimes subtended by calyculi (sing. calyculus); phyllaries borne in 1-5(-15+) series proximal to (i.e., outside of or abaxial to) the florets; receptacles usually flat to convex, sometimes conic or columnar, either paleate (bearing paleae or receptacular bracts that individually subtend some or all of the florets) or epaleate (lacking paleae); epaleate receptacles sometimes bristly or hairy or bearing subulate enations among the florets. Florets bisexual, pistillate, functionally staminate, or neuter (also called neutral); sepals highly modifed (instead of ordinary sepals, each ovary usually bears a pappus of bristles, awns, and/or scales, sometimes in combination within a single pappus); petals connate, corollas (3-)5-merous, ± actinomorphic or zygomorphic (one or both kinds in a single head, see descriptions of radiate, discoid, liguliflorous, disciform, and radiant following); stamens (4-)5, alternate with corolla lobes, filaments inserted on corollas, usually distinct, anthers introrse, usually connate and forming tubes around styles (rarely filaments connate and anthers distinct; e.g., Heliantheae, Ambrosiinae); ovaries inferior, 2-carpellate, and 1-locular with 1 basally attached, anatropous ovule; styles 1 in each bisexual, functionally staminate, or pistillate floret; each style usually ringed at base by a nectary, distally 2-branched with stigmatic papillae borne on adaxial face of each branch in 2 separate or contiguous lines or in 1 continuous band (
Desert Research Learning Center, Botany Program

The largest angiosperm family with over 22,000 described species globally, it is also one of the most distinctive in terms of its floral morphology. In North America there are 418 genera and about 2,400 species. Variable growth form, resin canals and/or lactifers often present. Leaves simple or compound, spiral or opposite, exstipulate. Inflorescence one or more heads arranged into various types of secondary inflorescences, each head subtended by phyllaries (bracts), heads of five general types: discoid, disciform, radiate, ligulate, and bilabiate. Flowers perfect, imperfect or sterile, radial or bilateral, of three types: bilabiate, disk, or ray/ligulate. Sepals highly modified, forming pappus composed of 2-many scales or bristles that are variously shaped, often hairy, barbed or plumose. Corolla of 5 connate petals, variously shaped. Stamens 5, usually with connate anthers, plunger pollen presentation, 2 connate carpels, and inferior ovaries with basal placentation. Fruit an achene (cypselae), usually arranged in a multiple fruit.

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Species within checklist: Glen Canyon National Recreation Area || << 1 - 50 taxa >>
Acamptopappus sphaerocephalus
Image of Acamptopappus sphaerocephalus
Acourtia wrightii
Image of Acourtia wrightii
Acroptilon repens
Image of Acroptilon repens
Ambrosia acanthicarpa
Image of Ambrosia acanthicarpa
Ambrosia psilostachya
Image of Ambrosia psilostachya
Artemisia bigelovii
Image of Artemisia bigelovii
Artemisia campestris
Image of Artemisia campestris
Artemisia carruthii
Image of Artemisia carruthii
Artemisia dracunculus
Image of Artemisia dracunculus
Artemisia filifolia
Image of Artemisia filifolia
Artemisia frigida
Image of Artemisia frigida
Artemisia ludoviciana
Image of Artemisia ludoviciana
Artemisia nova
Image of Artemisia nova
Baccharis emoryi
Image of Baccharis emoryi
Baccharis salicifolia
Image of Baccharis salicifolia
Baccharis salicina
Image of Baccharis salicina
Baccharis sarothroides
Image of Baccharis sarothroides
Baccharis wrightii
Image of Baccharis wrightii
Baileya multiradiata
Image of Baileya multiradiata
Bidens frondosa
Image of Bidens frondosa
Brickellia atractyloides
Image of Brickellia atractyloides
Brickellia longifolia
Image of Brickellia longifolia
Calycoseris parryi
Image of Calycoseris parryi
Chaenactis macrantha
Image of Chaenactis macrantha
Chaenactis stevioides
Image of Chaenactis stevioides
Chaetopappa ericoides
Image of Chaetopappa ericoides
Chloracantha spinosa
Image of Chloracantha spinosa
Chrysothamnus greenei
Image of Chrysothamnus greenei
Chrysothamnus scopulorum
Image of Chrysothamnus scopulorum
Cirsium neomexicanum
Image of Cirsium neomexicanum
Cirsium rothrockii
Image of Cirsium rothrockii
Cirsium rydbergii
Image of Cirsium rydbergii
Cirsium undulatum
Image of Cirsium undulatum
Cirsium vulgare
Image of Cirsium vulgare
Conyza canadensis
Image of Conyza canadensis
Dicoria canescens
Image of Dicoria canescens
Dieteria canescens
Image of Dieteria canescens
Dyssodia pentachaeta
Image of Dyssodia pentachaeta
Encelia frutescens
Image of Encelia frutescens
Encelia resinifera
Image of Encelia resinifera
Encelia virginensis
Image of Encelia virginensis
Enceliopsis nudicaulis
Image of Enceliopsis nudicaulis
Ericameria nauseosa
Image of Ericameria nauseosa
Erigeron bellidiastrum
Image of Erigeron bellidiastrum
Erigeron divergens
Image of Erigeron divergens
Erigeron kachinensis
Image of Erigeron kachinensis
Erigeron pumilus
Image of Erigeron pumilus
Erigeron religiosus
Image of Erigeron religiosus
Erigeron sparsifolius
Image of Erigeron sparsifolius
Erigeron utahensis
Image of Erigeron utahensis