Asteraceae

• Achillea millefolium L., Common yarrow, Native, Common, Photos Phytoimages, USDA_Plants

• Acroptilon repens (L.) DC., Russian knapweed, Synonyms: Centaurea repens L., Introduced, Larimer Co., Photos Phytoimages, USDA_Plants

• Agoseris aurantiaca var. aurantiaca (Hook.) Greene, Orange agoseris, Burnt-orange dandelion, Native, Common, Photos Phytoimages, USDA_Plants

• Agoseris aurantiaca var. purpurea (A. Gray) Cronquist, Orange agoseris, Burnt-orange dandelion, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Agoseris glauca var. glauca (Pursh) Raf., Pale agoseris, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Agoseris glauca var. dasycephala (Torr. & A.Gray) Jeps., Pale agoseris, Ppale goat-chicory, Synonyms: Agoseris glauca var. agrestis (Osterh.) Q. Jones ex Cronquist [Tall false dandelion], Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Agoseris parviflora (Nutt.) D. Dietr., Steppe agoseris, Synonyms: Agoseris glauca var. laciniata (D. C. Eaton) Kuntze, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Ambrosia acanthicarpa Hook., Annual bursage, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Ambrosia artemisiifolia L., Common ragweed, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Ambrosia psilostachya DC., Western ragweed, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Ambrosia tomentosa Nutt., Perennial bursage, Skeleton-leaf bursage, Native, Uncommon, Photos Phytoimages, USDA_Plants

• Ambrosia trifida L., Great ragweed, giant ragweed, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Anaphalis margaritacea (L.) A.Gray, Pearly everlasting, Synonyms: Anaphalis margaritacea var. angustior, Native, Common, Photos Phytoimages, USDA_Plants

• Antennaria anaphaloides Rydb., Pearly pussy-toes, Synonyms: Antennaria pulcherrima ssp. anaphaloides (Rydb.) W. A. Weber, Native, Common, Photos Phytoimages, USDA_Plants

• Antennaria corymbosa E.E. Nelson, Flat-top pussy-toes, Meadow everlasting, Native, Common, Photos Phytoimages, USDA_Plants

• Antennaria media Greene, Rocky Mountain pussy-toes, Native, Common, Photos Phytoimages, USDA_Plants

• Antennaria microphylla Rydb., Littleleaf pussy-toes, Rocky Mountain pussy-toes, Small leaf everlasting, Smallleaf pussy-toes, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Antennaria neglecta Greene, Field pussy-toes, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Antennaria parvifolia Nutt., Small leaf pussy-toes, Smalleaf pussy-toes, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Antennaria rosea (D.C.Eaton) Greene, Rosy pussy-toes, Native, Common, Photos Phytoimages, USDA_Plants

• Antennaria umbrinella Rydb., Umber pussy-toes, Brown everlasting, Native, Common, Photos Phytoimages, USDA_Plants

• Anthemis cotula L., Mayweed chamomile, Not listed for Larimer County in Ackerfield (2015) but present in Boulder, Weld and Jackson cos., Introduced, Common, Photos Phytoimages, USDA_Plants

• Arctium minus Bernh., Common burdock, Introduced, Uncommon, Photos Phytoimages, USDA_Plants

• Arnica chamissonis Less., Chamisso arnica, Native, Common, Photos Phytoimages, USDA_Plants

• Arnica cordifolia Hook., Heartleaf arnica, Native, Common, Photos Phytoimages, USDA_Plants

• Arnica fulgens Pursh, Foothill arnica, Meadow arnica, Native, Common, Photos Phytoimages, USDA_Plants

• Arnica latifolia Bong., Broadleaf arnica, Native, Common, Photos Phytoimages, USDA_Plants

• Arnica mollis Hook., Hairy arnica, Rayless arnica, Synonyms: Arnica ovata Greene, Native, Common, Photos Phytoimages, USDA_Plants

• Arnica parryi A. Gray, Parry's arnica, Native, Common, Photos Phytoimages, USDA_Plants

• Arnica rydbergii Greene, Rydberg's arnica, Native, Common, Photos Phytoimages, USDA_Plants

• Artemisia abrotanum L., Garden sagebrush, Southernwood, Introduced, Larimer Co., Photos Phytoimages, USDA_Plants

• Artemisia arbuscula Nutt. ssp. longiloba (Osterh.) L.M. Shultz, Little sagebrush, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Artemisia arctica Less., Boreal sagebrush, Arctic mountain-sage, Synonyms: Artemisia norvegica Fr. var. saxatilis (Besser) Jeps., Native, Common, Photos Phytoimages, USDA_Plants

• Artemisia biennis Willd., Biennial sagewort, Introduced, Larimer Co., Photos Phytoimages, USDA_Plants

• Artemisia campestris L. var. purshii (Hook.) Cronquist, Boreal sagewort, Synonyms: Artemisia borealis Pall, Artemisia campestris ssp. borealis, Artemisia spithamaea Pursh, Oligosporus groenlandicus (Hornem.) Á. Löve & D. Löve, Oligosporus campestris (L.) Cass., Native, Common, Photos Phytoimages, USDA_Plants

• Artemisia campestris L. var. caudata (Michx.) Palmer & Steyerm., Field sagewort, Synonyms: Artemisia caudata Michx., Oligosporus caudataus (Michx.) Poljakov, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Artemisia campestris L. var. pacifica (Nutt.) M. Peck, Field sagewort, Synonyms: Artemisia campestris var. scouleriana (Besser ex Besser) Cronquist, Artemisia campestris ssp. borealis var. scouleriana, Artemisia campestris subsp. pacifica (Nutt.) H.M.Hall & Clem., Oligosporus pacificus, Native, Uncommon, Photos Phytoimages, USDA_Plants

• Artemisia cana ssp. cana Pursh, Silver sagebrush, Silver sage, Hoary sagebrush, Native, Abundance - Unknown (eastern slope), Photos Phytoimages, USDA_Plants

• Artemisia cana ssp. viscidula (Osterh.) Beetle, Coaltown sagebrush, Mountain silver sagebrush, Silver sagebrush, Synonyms: Seriphidium canum (Pursh) W. A. Weber, Native, Common (western slope), Photos Phytoimages, USDA_Plants

• Artemisia carruthii Alph. Wood ex J. H. Carruth, Carruth's wormwood, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Artemisia dracunculus L., Wild Tarragon, Tarragon, Dragon sageworth, Native, Common, Photos Phytoimages, USDA_Plants

• Artemisia filifolia Torr., Sand sage, old-man sagebrush, Synonyms: Oligosporus filifolius (Torr.) Poljakov, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Artemisia frigida Willd., Prairie sagebrush, Fringed sagebrush, Silver Sage, Native, Common, Photos Phytoimages, USDA_Plants

• Artemisia ludoviciana var. ludoviciana Nutt., Louisiana sagewort, Louisiana wormwood, Cudweed sagewort, Gray sagewort, Mugwort wormwood, Prairie sage, White sagebrush, Native, Common, Photos Phytoimages, USDA_Plants

• Artemisia ludoviciana var. albula (Wooton) Shinners, White sagebrush, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Artemisia ludoviciana var. mexicana (Willd. ex Spreng.) A. Gray, Mexican sagebrush, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Artemisia ludoviciana var. incompta (Nutt.) Cronquist, White, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Artemisia nova A. Nelson, Black sagebrush, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Artemisia pattersonii A.Gray, Patterson Mountain-sage, Alpine sagebrush, Native, Common, Photos Phytoimages, USDA_Plants

• Artemisia scopulorum A.Gray, Dwarf sagebrush, Rocky Mountain-sage, Native, Common, Photos Phytoimages, USDA_Plants

• Artemisia spiciformis Osterh., Snowfield sagebrush, Subalpine big sagebrush, Synonyms: Artemisia tridentata ssp. spiciformis (Osterh.) Kartesz & Gandhi. Artemisia rothrockii A. Gray is from CA, not CO., Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Artemisia tridentata var. tridentata Nutt., Big sagebrush, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Artemisia tridentata Nutt. var. vaseyana (Rydb.) B. Boivin, Vasey's sagebrush, Synonyms: Artemisia tridentata ssp. vaseyana (Rydb.) Beetle, Native, Common, Photos Phytoimages, USDA_Plants

• Artemisia tridentata Nutt. var. wyomingensis (Beetle & A. L. Young) S. L. Welsh, Wyoming sagebrush, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Bahia dissecta (A.Gray) Britton, Ragleaf Bahia, Cutleaf, Synonyms: Amauriopsis dissecta (A. Gray) Rydb., Native, Common, Photos Phytoimages, USDA_Plants

• Balsamorhiza sagittata (Pursh) Nutt., Arrowleaf Balsamroot, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Bidens cernua L., Nodding beggar-ticks, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Bidens frondosa L., Devil's beggar-ticks, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Bidens tenuisecta A. Gray, Slimlobe beggar-ticks, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Bidens vulgata Greene, Tall beggar-ticks, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Brickellia californica (Torr. & A.Gray) A. Gray, California brickellbush, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Brickellia eupatorioides (L.) Shinners, False boneset, Synonyms: Kuhnia eupatorioides L., Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Brickellia grandiflora (Hook.) Nutt., Tasselflower brickellia, Tasselflower brickellbush, Native, Common, Photos Phytoimages, USDA_Plants

• Carduus nutans L., Musk Thistle, Nodding thistle, Synonyms: Carduus nutans ssp. macrolepis, Introduced, Abundant, Photos Phytoimages, USDA_Plants

• Centaurea cyanus L., Bachelor's button, Cornflower, Introduced, Larimer Co., Photos Phytoimages, USDA_Plants

• Centaurea diffusa Lam., Diffuse knapweed, Synonyms: Acosta diffusa (Lam.) Sojak, Introduced, Uncommon, Photos Phytoimages, USDA_Plants

• Centaurea stoebe L. ssp. micranthos (S. G. Gmelin ex Gugler) Hayek, Spotted knapweed, Synonyms: Centaurea biebersteinii DC., Centaurea maculosa Lam., Acosta maculosa (Lam.) Holub., Introduced, Uncommon, Photos Phytoimages, USDA_Plants

• Centaurea X psammogena G. Gayer, Hybrid knapweed, Hybrid between C. stoebe ssp. micranthos and C. diffusa Lam., Introduced, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Chaenactis douglasii (Hook.) Hook. & Arn., Dustymaiden, false yarrow, Synonyms: Chaenactis douglasii var. achilleaefolia (Hook. & Arn.) A. Nelson, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Chaenactis douglasii var. alpina A. Gray, Alpine dustymaiden, pincushion, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Chaetopappa ericoides (Torr.) G. L. Nelson, Rose heath, Synonyms: Leucelene ericoides (Torr. & Gray) Greene, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Chrysothamnus vaseyi (A. Gray) Greene, Vasey's rabbitbrush, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Chrysothamnus viscidiflorus var. lanceolatus (Nutt.) Greene, Lanceleaf rabbitbrush, Synonyms: Chrysothamnus viscidiflorus ssp. lanceolatus (Nutt.) H.M. Hall & Clem., Native, Common, Photos Phytoimages, USDA_Plants

• Chrysothamnus viscidiflorus var. viscidiflorus (Hook.) Nutt., Viscid rabbitbrush, Synonyms: Chrysothamnus viscidiflorus (Hook.) Nutt. ssp. axillaris (Keck) L. C. Anderson, C. viscidiflorus (Hook.) Nutt. ssp. stenophyllus (A. Gray) Hall & Clements, Chrysothamnus viscidiflorus ssp. lanceolatus (Nutt.) H.M. Hall & Clem., Native, Common, Photos Phytoimages, USDA_Plants

• Cichorium intybus L., Common chicory, Introduced, Larimer Co., Photos Phytoimages, USDA_Plants

• Cirsium arvense (L.) Scop., Canada Thistle, Synonyms: Breea arvensis (L.) Less, Introduced, Common, Photos Phytoimages, USDA_Plants

• Cirsium canescens Nutt., Prairie thistle, Synonyms: Cirsium plattense (Rydb.) Cockerell ex Daniels, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Cirsium clavatum (M. E. Jones) Petr., Fish lake thistle, Synonyms: Cirsium centaureae (A.Gray) D.J.Keil, Cirsium griseum (Rydb.) K. Schum, Cirsium modestum (Osterh.) Cockerell, Cirsium oreophilum (rydb.) K. Schum, Cirsium scapanolepis Petr., Cirsium spathulifolium Rydb., Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Cirsium clavatum (M. E. Jones) Petr. var. americanum (A. Gray) D. J. Keil, Rockly Mountain fringed thistle, American Thistle, Synonyms: Cirsium centaureae (Rydb.) K. Schum., Native, Common, Photos Phytoimages, USDA_Plants

• Cirsium coloradense (Rydb.) D.J.Keil, Colorado Thistle, Native, Common, Photos Phytoimages, USDA_Plants

• Cirsium eatonii (A.Gray) B.L.Rob., Eaton's thistle, mountaintop thistle, Synonyms: Cirsium tweedyi (Rydb.) Petr., Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Cirsium flodmanii (Rydb.) Arthur, Flodman's thistle, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Cirsium ochrocentrum A.Gray, Yellowspine thistle, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Cirsium scariosum (Poir.) Nutt., Meadow thistle, Elk thistle, Synonyms: Cirsium acaulescens K. Shum, Cirsium coloradense Cockerell ex Daniels, Cirsium drummondii misapplied, not Torr. & Gray, Cirsium erosum (Rydb.) K. Schum, Cirsium tioganum (Congd.) Petr., Cirsium tioganum var. coloradense (Rydb.) D.J.Keil, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Cirsium scopulorum (Greene) Cockerell ex Daniels, Mountain thistle, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Cirsium undulatum (Nutt.) Spreng., Wavyleaf thistle, Purple thistle, Native, Common, Photos Phytoimages, USDA_Plants

• Cirsium vulgare (Savi) Ten., Bull Thistle, Introduced, Rare, Photos Phytoimages, USDA_Plants

• Conyza canadensis L., Horseweed, Introduced, Common, Photos Phytoimages, USDA_Plants

• Crepis acuminata Nutt., Tapertip hawk's-beard, Synonyms: Psilochenia acuminata (Nutt. ) W. A. Weber, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Crepis atribarba A. Heller, Slender hawk's-beard, Synonyms: Psilochenia atribarba (A. Heller ) W. A. Weber, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Crepis capillaris (L.) Wallr., Smooth hawk's-beard, Introduced, Larimer Co., Photos Phytoimages, USDA_Plants

• Crepis modocensis Greene, Modoc hawk's-beard, Synonyms: Psilochenia modocensis (Greene) W. A. Weber, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Crepis occidentalis Nutt., Largeflower hawk's-beard, Synonyms: Psilochenia occidentalis (Nutt.) Nutt., Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Crepis occidentalis Nutt. ssp. conjuncta Babcock & Stebbins, Largeflower hawk's-beard, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Crepis occidentalis Nutt. ssp. costata (A. Gray) Babcock & Stebbins, Largeflower hawk's-beard, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Crepis runcinata (E.James) Torr. & A.Gray, Dandelion hawksbeard, Fiddle-leaf hawk's-beard, Fiddleleaf hawk's-beard, Synonyms: Psilochenia runcinata (E. James) Á. Löve & D. Löve, Native, Common, Photos Phytoimages, USDA_Plants

• Crepis runcinata ssp. glauca (Nutt.) Babcock & Stebbins, Dandelion hawksbeard, Fiddle-leaf hawk's-beard, Fiddleleaf hawk's-beard, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Crepis runcinata ssp. hispidulosa (Howell ex Rydb.) Babcock & Stebbins, Dandelion hawksbeard, Fiddle-leaf hawk's-beard, Fiddleleaf hawk's-beard, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Cyclachaena xanthifolia (Nutt.) Fresen., Giant sumpweed, Horseweed, Synonyms: Iva xanthifolia Nutt., Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Dieteria bigelovii (A.Gray) D.R.Morgan & R.L.Hartm., Bigelow's tansy-aster, Synonyms: Machaeranthera bigelovii (A. Gray) Greene var. bigelovii, Machaeranthera pattersonii (A. Gray) Greene, Native, Common, Photos Phytoimages, USDA_Plants

• Dieteria canescens (Pursh) Nutt., Hoary tansy-aster, Synonyms: Machaeranthera canescens (Pursh) A. Gray, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Dyssodia papposa (Vent.) Hitchc., Fetid marigold, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Ericameria nauseosa (Pall. ex Pursh) G. L. Nelson & G. I. Baird, Rubber rabbitbrush, Native, Common, Photos Phytoimages, USDA_Plants

• Ericameria nauseosa var. bigelovii (A. Gray) G. L. Nelson & G. I. Baird, Rubber rabbitbrush, Synonyms: Chrysothamnus nauseosus (Pall. ex Pursh) Britton var. bigelovii (A. Gray) Hall & Clements, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Ericameria nauseosa var. juncea (Greene) G. L. Nesom & G. I. Baird, Rubber rabbitbrush, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Ericameria nauseosa var. leiosperma (A. Gray) G. L. Nelson & G. I. Baird, Rubber rabbitbrush, Synonyms: Chrysothamnus nauseosus (Pall. ex Pursh) Britton var. leiospermus (A. Gray) Hall, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Ericameria nauseosa var. graveolens (Nutt.) Reveal & Schuyler, Rubber rabbitbrush, Synonyms: Chrysothamnus nauseosus (Pall. ex Pursh) Britton ssp. graveolens (Nutt.) Piper, Chrysothamnus nauseosus (Pall. ex Pursh) Britton var. glabratus (A. Gray) Cronquist, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Ericameria nauseosa var. nauseosa (Pall. ex Pursh) G. L. Nelson & G. I. Baird, Rubber rabbitbrush, Synonyms: Chrysothamnus nauseosus (Pall. ex Pursh) Britton var. nauseosus, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Ericameria parryi var. parryi (A.Gray) G.L.Nesom & Baird, Parry's rabbitbrush, Synonyms: Chrysothamnus parryi (A. Gray) Greene ssp. parryi, Native, Common, Photos Phytoimages, USDA_Plants

• Ericameria parryi var. howardii (Parry ex A. Gray) G. L. Neson & G. I. Baird, Parry's rabbitbrush, Synonyms: Chrysothamnus parryi (A. Gray) Greene ssp. howardii (Parry ex A. Gray) Hall & Clements, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Erigeron acris L., Bitter fleabane, Synonyms: Trimorpha acris (L. ) A. Gray, Erigeron acris ssp. politus (Fr.) Schinz & R. Keller a synonym? Plant List has. Erigeron acris subsp. politus (Fr.) H.Lindb. as an accepted name., Native, Common, Photos Phytoimages, USDA_Plants

• Erigeron caespitosus Nutt., Tufted daisy, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Erigeron canus A. Gray, Hoary daisy, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Erigeron compositus Pursh, Cutleaf daisy, Cut-leaved daisy, Native, Common, Photos Phytoimages, USDA_Plants

• Erigeron coulteri Porter, Coulter's daisy, Native, Common, Photos Phytoimages, USDA_Plants

• Erigeron divergens Torr. & A.Gray, Spreading daisy, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Erigeron eatonii A.Gray, Eaton's daisy, Eaton's fleabane, Native, Common, Photos Phytoimages, USDA_Plants

• Erigeron elatior (A.Gray) Greene, Tall daisy, Tall fleabane, Beautiful daisy, Native, Common, Photos Phytoimages, USDA_Plants

• Erigeron eximius Greene, Splendid daisy, Pale daisy, Native, Common, Photos Phytoimages, USDA_Plants

• Erigeron flagellaris A.Gray, Trailing daisy, Whiplash daisy, Native, Common, Photos Phytoimages, USDA_Plants

• Erigeron formosissimus Greene, Greene's Daisy, Beautiful daisy, Native, Common, Photos Phytoimages, USDA_Plants

• Erigeron glabellus Nutt., Smooth daisy, Smooth fleabane, Streamside fleabane, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Erigeron glacialis (Nutt.) A. Nelson, Glacial daisy, Not Erigeron peregrinus ssp. callianthemus (Greene) Cronquist [subalpine daisy] or E. peregrinus (Banks ex Pursh) Greene which is restricted to the NW US and Canada, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Erigeron grandiflorus Hook., Rocky Mountain alpine daisy, Arctic fleabane, Synonyms: Erigeron simplex Greene, Native, Common, Photos Phytoimages, USDA_Plants

• Erigeron leiomerus A.Gray, Rockslide daisy, Rockslide yellow fleabane, Glaber daisy, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Erigeron lonchophyllus Hook., Shortray fleabane, longleaf daisy, Spearleaf fleabane, Synonyms: Trimorpha lonchophylla var. laurentiana, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Erigeron melanocephalus (A.Nelson) A.Nelson, Blackhead daisy, Black-headed daisy, Native, Common, Photos Phytoimages, USDA_Plants

• Erigeron nematophyllus Rydb., Needleleaf daisy, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Erigeron pinnatisectus (A.Gray) A.Nelson, Featherleaf daisy, Pinnate-leaved daisy, Native, Common, Photos Phytoimages, USDA_Plants

• Erigeron pumilus Nutt., Shaggy daisy, Dwarf daisy, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Erigeron speciosus (Lindl.) DC., Aspen daisy, Aspen fleabane, Oregon daisy, Oregon fleabane, Threenerve fleabane, Dryland daisy, Synonyms: Erigeron speciosus var. macranthus (Nutt.) Cronquist, Native, Common, Photos Phytoimages, USDA_Plants

• Erigeron strigosus Muhl. ex Willd., Prairie fleabane, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Erigeron subtrinervis Rydb. ex Porter & Britton, Threenerve daisy, Native, Common, Photos Phytoimages, USDA_Plants

• Erigeron tracyi Greene, Running daisy, Running fleabane, Synonym: Erigeron colomexicanus A. Nelson, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Erigeron ursinus D.C.Eaton, Bear River daisy, Bear daisy, Bear River fleabane, Native, Common, Photos Phytoimages, USDA_Plants

• Erigeron vetensis Rydb., Early bluetop daisy, Early blue daisy, Native, Common, Photos Phytoimages, USDA_Plants

• Eucephalus engelmannii (D.C.Eaton) Greene, Engelmann's aster, Native, Common, Photos Phytoimages, USDA_Plants

• Eutrochium maculatum (L.) E. E. Lamont, Spotted joepyeweed, Synonyms: Eupatorium maculatum L. var. bruneri (A. Gray) Breit, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Gaillardia aristata Pursh, Blanketflower, Native, Common, Photos Phytoimages, USDA_Plants

• Galinsoga parviflora Cav., Quickweed, Introduced, Larimer Co., Photos Phytoimages, USDA_Plants

• Galinsoga quadriradiata Ruiz & Pav., Fringed quickweed, Shaggy soldier, Introduced, Larimer Co., Photos Phytoimages, USDA_Plants

• Gnaphalium exilifolium A. Nelson, Slender cudweed, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Gnaphalium palustre Nutt., Diffuse cudweed, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Gnaphalium uliginosum L., Low cudweed, Marsh cudweed, Introduced, Common, Photos Phytoimages, USDA_Plants

• Grindelia hirsutula Hook. & Arn. var. revoluta (Steyerm.) Ackerfiled comb. nov., Hirsute gumweed, Rolled gumweed, Synonyms: Grindelia revoluta Steyerm. Ackerfield indicates this variety is present from El Paso county south, so its presence in RMNP is questionable, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Grindelia squarrosa var. squarrosa (Pursh) Dunal, Curlycup gumweed, Curlytop gumweed, Gumweed, Rosinweed, Tarweed, Native, Common, Photos Phytoimages, USDA_Plants

• Grindelia squarrosa (Pursh) Dunal var. quasiperennis Lunnel, Curlycup gumweed, Curlytop gumweed, Gumweed, Rosinweed, Tarweed, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Grindelia squarrosa (Pursh) Dunal var. serrulata (Rydb.) Steyerm., Curlycup gumweed, Curlytop gumweed, Gumweed, Rosinweed, Tarweed, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Grindelia subalpina Greene, Subalpine gumweed, Mountain gumweed, Native, Common, Photos Phytoimages, USDA_Plants

• Gutierrezia sarothrae (Pursh) Britton & Rusby, Broom snakewed, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Helianthella quinquenervis (Hook.) A.Gray, Aspen Sunflower, Native, Common, Photos Phytoimages, USDA_Plants

• Helianthus annuus L., Common Sunflower, Native, Common, Photos Phytoimages, USDA_Plants

• Helianthus ciliaris DC., Texas blueweed, Introduced, Larimer Co., Photos Phytoimages, USDA_Plants

• Helianthus nuttallii Torr. & A.Gray, Nuttall's sunflower, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Helianthus pumilus Nutt., Dwarf sunflower, Little sunflower, Native, Common, Photos Phytoimages, USDA_Plants

• Helianthus rigidus Desf. ssp. subrhomboideus (Rydb.) Heiser, Stiff sunflower, Synonyms: Helianthus pauciflorus Nutt. ssp. subrhomboideus (Rydb.) O. Spring & Schilling, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Heliomeris multiflora var. multiflora Nutt., Showy goldeneye, Showy goldeneyes, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Heliomeris multiflora Nutt. var. nevadensis (A. Nelson) W. F. Yates, Nevada goldeneye, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Herrickia glauca (Nutt.) Brouillet, Gray aster, Synonyms: Aster glaucodes S. F. Blake, Eucephalus glaucus Nutt., Eurybia glauca var. pulcra (S. F. Blake) Brouillet, Eurybia glauca (Nutt.) G.L.Nesom, Native, Common, Photos Phytoimages, USDA_Plants

• Heterotheca foliosa (Nutt.) Shinners, Foliose false goldenaster, Mountain camphorweed, Rockyscree false goldenaster, Rockyscree falsegoldenaster, Synonyms: Heterotheca fulcrata (Greene) Shinners, Native, Common, Photos Phytoimages, USDA_Plants

• Heterotheca pumila (Greene) Semple, Alpine false goldenaster, Native, Common, Photos Phytoimages, USDA_Plants

• Heterotheca villosa var. vilosa (Pursh) Shinners, Hairy false goldaster, Hairy false goldenaster, Hairy goldaster, Hairy goldenaster, Native, Common, Photos Phytoimages, USDA_Plants

• Heterotheca villosa var. minor (Hook.) Semple, Hairy false goldaster, Hairy false goldenaster, Hairy goldaster, Hairy goldenaster, Synonyms: Heterotheca villosa (Pursh) Shinners var. hispida (Hook.) Harms, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Heterotheca villosa var. nana (A. Gray) Semple, Hairy false goldaster, Hairy false goldenaster, Hairy goldaster, Hairy goldenaster, Synonyms: Heterotheca horrida (Rydb.) Harms, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Heterotheca villosa var. scabra (Eastw.) Semple, Hairy false goldaster, Hairy false goldenaster, Hairy goldaster, Hairy goldenaster, Synonyms: Heterotheca horrida (Rydb.) Harms ssp. cinerascens (Blake) Semple, Heterotheca polothrix G. L. Nesom, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Hieracium albiflorum Hook., White hawkweed, Whiteflower hawkweed, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Hieracium fendleri Sch. Bip., Yellow hawkweed, Synonyms: Chlorocrepis fendleri (Sch. Bip.) W. A. Weber, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Hieracium triste Willd. ex Spreng., Slender hawkweed, Synonyms: Hieracium gracile Hook., Chlorocrepis tristis (Willd. ex Spreng.) Á. Löve & D. Löve, Native, Common, Photos Phytoimages, USDA_Plants

• Hymenopappus filifolius Hook., Fineleaf hymenopappus, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Hymenopappus filifolius var. parvulus (Greene) B. L. Turner, Fineleaf hymenopappus, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Hymenopappus filifolius var. cinereus (Rydb.) I. M. Johnst., Fineleaf hymenopappus, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Hymenopappus tenuifolius Pursh, Chalk hill hymenopappus, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Hymenoxys grandiflora (Torr. & A.Gray ex A. Gray) Parker, Old man of the mountain, Alpine sunflower, Synonyms: Tetraneuris grandiflora (Torr. & A. Gray ex A. Gray) Parker, Native, Common, Photos Phytoimages, USDA_Plants

• Hymenoxys hoopesii (A. Gray) Bierner, Orange sneezeweed, Owl's claws, Synonyms: Dugaldia hoopsii Rydb., Helenium hoopesii A. Gray, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Hymenoxys richardsonii (Hook.) Cockerell, Colorado rubberweed, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Iva axillaris Pursh, Poverty weed, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Lactuca biennis (Moench) Fernald, Tall blue lettuce, Wild blue lettuce, Lactuca spicata (Lam.) A. S. Hitchc., Native, Uncommon, Photos Phytoimages, USDA_Plants

• Lactuca canadensis L., Canada lettuce, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Lactuca ludoviciana (Nutt.) Riddell, Biannual lettuce, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Lactuca serriola L., Prickly lettuce, Introduced, Larimer Co., Photos Phytoimages, USDA_Plants

• Lactuca tatarica (L.) C. A. Mey var. pulchella (Pursh) Breitung, Blue lettuce, Synonyms: Lactuca oblongifolia Nutt., Lactuca pulchella (Pursh) DC., Mulgedium pulchellum (Pursh) G. Don, Mulgedium pulchellum (Pursh) G. Don in Sweet, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Laennecia schiedeana (Less) G. L. Nesom, Pineland marshtail, Synonyms: Conyza schiedeana (Less) Cronquist, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Leucanthemum vulgare (Vaill.) Lam., Oxeye daisy, Ox-eye daisy, Synonyms: Chrysanthemum leucanthemum L., Introduced, Common, Photos Phytoimages, USDA_Plants

• Liatris ligulistylis (A.Nelson) K.Schum., Rocky Mountain blazing star, Rocky Mountain gayfeather, Strap-style gayfeather, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Liatris punctata Hook., Dotted blazing star, Gayfeather, Native, Common, Photos Phytoimages, USDA_Plants

• Lygodesmia juncea (Pursh) D.Don ex Hook., Rush skeletonweed, Native, Uncommon, Photos Phytoimages, USDA_Plants

• Machaeranthera tanacetifolia (Kunth) Nees, Tanseyleaf tansy-aster, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Madia glomerata Hook., Mountain tarweed, Native, Common, Photos Phytoimages, USDA_Plants

• Matricaria discoidea DC., Pineapple weed, Synonyms: Lepidotheca suaveolens (Pursh) Nutt., Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Microseris nutans (Hook.) Sch. Bip., Nodding silverpuffs, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Nothocalais cuspidata (Pursh) Greene, Sharppoint prairie-dandelion, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Onopordum acanthium L., Scotch cottonthistle, Another species, Onopordum tauricum Willd., has been reported from RMNP, but this needs to be confirmed because acc. to Ackerfield (2015), this species is only in Pueblo and Huerfano counties, Introduced, Rare, Photos Phytoimages, USDA_Plants

• Oönopsis wardii (A.Gray) Greene, Ward's false goldenweed, Near Holnholz Lakes (7800-7900 ft.), Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Oreochrysum parryi (A.Gray) Rydb., Parry's goldenrod, Synonyms: Haplopappus parryi A. Gray, Solidago parryi (A. Gray) Greene, Native, Common, Photos Phytoimages, USDA_Plants

• Packera cana (Hook.) W.A.Weber & Á.Löve, Woolly groundsel, Synonyms: Senecio canus Hook., Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Packera crocata (Rydb.) W.A.Weber & Á.Löve, saffron ragwort, Synonyms: Packera dimorphophylla (Greene) W.A.Weber & Á.Löve, Senecio crocatus Rydb., Native, Common, Photos Phytoimages, USDA_Plants

• Packera debilis (Nutt.) W. A. Weber & Á. Löve, Weak groundsel, Synonyms: Senecio debilis Nutt., Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Packera fendleri (A.Gray) W.A.Weber & Á.Löve, Fendler's ragwort, Synonyms: Senecio fendleri A. Gray, Native, Common, Photos Phytoimages, USDA_Plants

• Packera multilobata (Torr. & A.Gray) W. A. Weber & Á.Löve, Lobeleaf groundsel, Synonyms: Senecio multilobatus Torr. & A. Gray ex A. Gray, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Packera plattensis (Nutt.) W. A. Weber & Á. Löve, Prairie groundsel, Synonyms: Senecio plattensis Nutt., Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Packera pseudaurea (Rydb.) W.A.Weber & Á.Löve var. flavula (Greene) W.A.Weber & Á.Löve, Falsegold groundsel, Synonyms: Senecio pseudaureus Rydb. var. flavulus (Greene) Greenm., Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Packera streptanthifolia (Greene) W.A.Weber & Á.Löve, Rocky Mountain groundsel, Cleftleaf groundsel, Synonyms: Senecio streptanthifolius Greene. Not reported for Larimer county in Ackerfield (2015), Native, Common, Photos Phytoimages, USDA_Plants

• Packera tridenticulata (Rydb.) W.A.Weber & Á.Löve, Threetooth ragwort, Synonyms: Senecio tridenticulatus Rydb., Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Packera werneriifolia (A.Gray) W.A.Weber & Á.Löve, Hoary groundsel, Synonyms: Packera mancosana Yeatts, B Schneid, & Al Schneid, Senecio werneriifolius (A. Gray) A. Gray, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Palafoxia sphacelata (Nutt. ex Torr.) Cory, Othake, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Petasites frigidus (L.) Fries var. sagittatus (Banks ex Pursh) Cherniawsky., Arrowleaf sweet coltsfoot, Synonyms: Petasites sagittatus (Banks ex Pursh) A. Gray, Native, Common, Photos Phytoimages, USDA_Plants

• Picradeniopsis oppositifolia (Nutt.) Rydb., Opposite leaf bahia, Synonyms: Bahia oppositifolia (Nutt.) DC., Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Hieracium aurantiacum (L.) F.W.Schultz & Sch.Bip., Orange Hawkweed, Synonyms: Pilosella aurantiaca (L.) F.W.Schultz & Sch.Bip., Introduced, Rare, Photos Phytoimages, USDA_Plants

• Prenanthes racemosa Michx., Rattlesnake-root, White lettuce, Native, Uncommon, Photos Phytoimages, USDA_Plants

• Pseudognaphalium canescens (DC.) W. A. Weber, Wright's cudweed, Synonyms: Gnaphalium wrightii A. Gray, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Pseudognaphalium macounii (Greene) Kartesz, Macoun's cudweed, Synonyms: Gnaphalium macounii Greene, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Pseudognaphalium stramineum (Kunth) Anderb., Winged cudweed, Annual cudweed, Cotton cudweed, Cottonbatting cudweed, Cottonbatting plant, Synonyms: Gnaphalium chilense Spreng., Gnaphalium stramineum Kunth, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Pseudognaphalium viscosum (Kunth) Anderb., Cudweed, Accepted name on Plant List, not listed in Ackerfield (2015), Native, Common, Photos Phytoimages, USDA_Plants

• Pyrrocoma crocea (A.Gray) Greene, Curlyhead goldenweed, Not shown in Larimer county in Ackerfield (2015), Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Pyrrocoma lanceolata (Hook.) Greene, Lanceleaf goldenweed, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Ratibida columnifera (Nutt.) Wooton & Standl., Prairie coneflower, Native, Common, Photos Phytoimages, USDA_Plants

• Rayjacksonia annua (Rydb.) R. L. Hartm. & M. A. Lane, Viscid camphor-daisy, Synonyms: Haplopappus annuus (Rydb.) Cory, Haplopappus phyllocephalus DC. ssp. annuus (Rydb.) Hall, Machaeranthera annua (Rydb.) Shinners (A. Gray) Greene, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Rudbeckia hirta L. var. pulcherrima Farw., Black-eyed Susan, Native, Common, Photos Phytoimages, USDA_Plants

• Rudbeckia laciniata L. var. ampla (A.Nelson) Cronquist, Cutleaf coneflower, Green-head coneflower, Native, Common, Photos Phytoimages, USDA_Plants

• Rudbeckia triloba L., Brown-eyed Susan, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Scorzonera laciniata L., Cutleaf vipergrass, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Senecio amplectens var. amplectens A.Gray, Showy alpine ragwort, Synonyms: Ligularia amplecens (A. Gray) W. A. Weber, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Senecio amplectens A.Gray var. holmii (Greene) H.D.Harr., Holm's groundsel, Holm's ragwort, Native, Common, Photos Phytoimages, USDA_Plants

• Senecio atratus Greene, Tall blacktip ragwort, Black-tipped senecio, Native, Common, Photos Phytoimages, USDA_Plants

• Senecio bigelovii A. Gray var. hallii A.Gray, Hall's ragwort, Bigelow's groundsel, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Senecio crassulus A.Gray, Mountain meadow ragwort, Thick-bracted senecio, Native, Common, Photos Phytoimages, USDA_Plants

• Senecio eremophilus Richardson var. kingii (Rydb.) Greenm., Cut-leaved groundsel, Western golden ragwort, Native, Common, Photos Phytoimages, USDA_Plants

• Senecio fremontii Torr. & A. Gray var. blitoides (Greene) Cronquist, Dwarf mountain ragwort, Rock ragwort, Native, Common, Photos Phytoimages, USDA_Plants

• Senecio hydrophilus Nutt., Alkali-marsh ragwort, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Senecio integerrimus Nutt., Lambs-tongue ragwort, Lambs-tongue groundsel, Gauge-plant, Native, Common, Photos Phytoimages, USDA_Plants

• Senecio pudicus Greene, Bashful ragwort, Synonyms: Ligularia pudica (Greene) W. A. Weber, Native, Common, Photos Phytoimages, USDA_Plants

• Senecio rapifolius Nutt., Open-woods ragwort, Turnip-leaved senecio, Native, Common, Photos Phytoimages, USDA_Plants

• Senecio riddellii Torr. & A.Gray, Riddell's ragwort, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Senecio serra Hook. var. admirabilis (Greene) A. Nelson, Saw-toothed ragwort, Tall ragwort, Butterweed, Butterweed groundsel, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Senecio soldanella A.Gray, Colorado ragwort, Synonyms: Ligularia soldanella (A. Gray) W. A. Weber, Native, Common, Photos Phytoimages, USDA_Plants

• Senecio spartioides Torr. & A.Gray, Narrow-leaved ragwort, Broom senecio, Native, Common, Photos Phytoimages, USDA_Plants

• Senecio taraxacoides (A.Gray) Greene, Dandelion ragwort, Synonyms: Ligularia taraxacoides (A. Gray) W. A. Weber, Native, Uncommon, Photos Phytoimages, USDA_Plants

• Senecio triangularis Hook., Arrowleaf ragwort, Native, Common, Photos Phytoimages, USDA_Plants

• Senecio vulgaris L., Old man in the spring, groundsel, Introduced, Larimer Co., Photos Phytoimages, USDA_Plants

• Senecio wootonii Greene, Wooton's ragwort, Wooton's senecio, Native, Common, Photos Phytoimages, USDA_Plants

• Solidago canadensis L., Canada goldenrod, Canadian goldenrod, Common goldenrod, Synonyms: Solidago altissima L., Native, Common, Photos Phytoimages, USDA_Plants

• Solidago gigantea Aiton, Giant goldenrod, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Solidago missouriensis Nutt., Missouri goldenrod, Smooth goldenrod, Native, Common, Photos Phytoimages, USDA_Plants

• Solidago mollis Bartl., Soft goldenrod, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Solidago multiradiata Ait. var. scopulorum A.Gray, Rocky Mountain goldenrod, Manyray goldenrod, Synonyms: Solidago multiradiata subsp. scopulorum (A. Gray) W. A. Weber, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Solidago nana Nutt., Baby goldenrod, Dwarf goldenrod, Synonyms: Solidago simplex subsp. simplex var. nana, Native, Common, Photos Phytoimages, USDA_Plants

• Solidago nemoralis Ait. var. decemflora (DC.) Brammall ex Semple, Gray goldenrod, Synonyms: Solidago nemoralis Ait var. longipetiolata (Mack. & Bush) Palmer & Steyerm., Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Solidago ptarmicoides (Nees) Boivin, Prairie goldenrod, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Solidago rigida L. var. humilis Porter, stiff goldenrod, Synonyms: Oligoneuron rigidum (L.) Small, Native, Common, Photos Phytoimages, USDA_Plants

• Solidago simplex var. simplex Kunth, Mt. Albert goldenrod, New Mexican goldenrod, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Solidago speciosa Nutt. var. pallida Porter, Showy goldenrod, Native, Uncommon, Photos Phytoimages, USDA_Plants

• Solidago velutina DC. ssp. sparsiflora (A. Gray) Semple, Threenerve goldenrod, Three-nerve goldenrod, Sparse goldenrod, Synonyms: Solidago sparsiflora A. Gray, Native, Common, Photos Phytoimages, USDA_Plants

• Sonchus arvensis L., Field sow-thistle, Introduced, Uncommon, Photos Phytoimages, USDA_Plants

• Sonchus asper (L.) Hill, Spiny sow-thistle, Introduced, Larimer Co., Photos Phytoimages, USDA_Plants

• Sonchus oleraceus L., Common sow-thistle, Introduced, Larimer Co., Photos Phytoimages, USDA_Plants

• Sonchus uliginosus M. Bieb., Moist sow-thistle, Marsh sowthistle, Swamp sow-thistle, Synonyms: Sonchus arvensis L. ssp. uliginosus (M. Bieb.) Nyman, Introduced, Larimer Co., Photos Phytoimages, USDA_Plants

• Stenotus acaulis (Nutt.) Nutt., Stemless mock goldenweed, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Stenotus armerioides Nutt., Thrift mock goldenweed, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Stephanomeria pauciflora (Torr.) A.Nelson, Brownplume wire lettuce, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Stephanomeria runcinata Nutt., Desert wire lettuce, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Symphyotrichum ascendens (Lindl.) G.L.Nesom, Western aster, Pacific aster, Synonyms: Virgulaster ascendens (Lindl.) Semple, Aster ascendens Lindl. An allotetraploid from the hybridization of S. falcatum and S. spathulatum., Native, Common, Photos Phytoimages, USDA_Plants

• Symphyotrichum boreale (Torr. & A.Gray) Á.Löve & D.Löve, Slender white bog aster, Northern bog aster, Synonyms: Aster borealis (Torr. & A. Gray) Prov., Native, Rare, Photos Phytoimages, USDA_Plants

• Symphyotrichum campestre (Nutt.) G.L.Nesom, Western meadow aster, Synonyms: Aster campestris Nutt., Virgulus campestris (Nutt.) Reveal & Keener, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Symphyotrichum ciliatum (Ledeb.) G. L. Nesom, Rayless alkali aster, Synonyms: Aster brachyactis S. F. Blake, Bracyactis ciliata (Ledeb. ) Ledeb. ssp. angusta (lindl.) A. G. Jones, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Symphyotrichum ericoides (L.) G.L.Nesom, White aster, Sand aster, Synonyms: Aster ericoides L, Virgulus ericoides (L.) Reveal & Keener, Native, Uncommon, Photos Phytoimages, USDA_Plants

• Symphyotrichum falcatum (Lindl.) G.L.Nesom, White prairie aster, Rough white aster, Synonyms: Aster falcatus Lindl., Virgulus falcatus (Lindl.) Reveal & Keener, Native, Common, Photos Phytoimages, USDA_Plants

• Symphyotrichum fendleri (A.Gray) G.L.Nesom, Fendler's aster, Synonyms: Aster fendleri A. Gray, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Symphyotrichum foliaceum (DC.) G.L.Nesom var. apricum (A.Gray) G.L.Nesom, Alpine leafy aster, Subalpine aster, Alpine leafybract aster, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Symphyotrichum foliaceum (DC.) G.L.Nesom var. canbyi (A.Gray) G.L.Nesom, Canby's aster, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Symphyotrichum foliaceum (DC.) G.L.Nesom var. parryi (D. C. Eaton) G. L. Nesom, Parry's aster, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Symphyotrichum laeve (L.) Á.Löve & D.Löve var. geyeri (A.Gray) G.L.Nesom, Smooth blue aster, Smooth aster, Synonyms: Aster laevis L. var. geyeri A. Gray, Native, Common, Photos Phytoimages, USDA_Plants

• Symphyotrichum lanceolatum (Willd.) G. L. Nesom ssp. hesperium (A.Gray) G.L.Nesom, Western lined aster, White panicle aster, Synonyms: Aster lanceolatus ssp. hesperius (A. Gray) G.L. Nesom, Aster hesperius A. Gray, Native, Common, Photos Phytoimages, USDA_Plants

• Symphyotrichum porteri (A.Gray) G.L.Nesom, Smooth white aster, Porter's aster, Synonyms: Aster porteri A. Gray, Native, Common, Photos Phytoimages, USDA_Plants

• Symphyotrichum spathulatum (Lindl.) G.L.Nesom, Western mountain aster, Synonyms: Aster spathulatus, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Tanacetum balsamita L., Costmary, Synonyms: Balsamita major Desf., Chrysanthemum balsamita L., Introduced, Larimer Co., Photos Phytoimages, USDA_Plants

• Tanacetum vulgare L., Tansy, Introduced, Larimer Co., Photos Phytoimages, USDA_Plants

• Taraxacum ceratophorum (Ledeb.) DC., Northern dandelion, Synonyms: Taraxacum ovinum Rydb., Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Taraxacum eriophorum Rydb., Woolbearing dandelion, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Taraxacum laevigatum (Willd.) DC., Rock dandelion, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Taraxacum officinale F. H. Wigg., Common dandelion, Synonyms: Taraxacum officinale ssp. ceratophorum (Ledeb.) Schinz ex Thell. (unresolved on Plant List), Introduced, Abundant, Photos Phytoimages, USDA_Plants

• Taraxacum scopulorum (A. Gray) Rydb., Alpine dandelion, Synonyms: Taraxacum lyratum (Ledeb.) DC., Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Tetradymia canescens DC., Common horsebrush, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Tetraneuris acaulis var. acaulis (Pursh) Greene, Stemless four-nerve daisy, Synonyms: Hymenoxys acaulis (Pursh) Parker, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Tetraneuris acaulis (Pursh) Greene var. arizonica (Greene) Parker, Arizona four-nerve daisy, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Tetraneuris acaulis (Pursh) Greene var. caespitosa A.Nelson, caespitose four-nerve daisy, Native, Common, Photos Phytoimages, USDA_Plants

• Tetraneuris acaulis (Pursh) Greene var. epunctata (A. Nelson) Kartesz, Stemless four-nerve daisy, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Tetraneuris scaposa (DC.) Greene, Stemmy four-nerve daisy, Synonyms: Hymenoxys scaposa (DC.) Parker var. scaposa, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Thelesperma filifolium (Hook.) A. Gray, Stiff greenthread, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Thelesperma megapotamicum (Spreng.) Kuntze, Hopi tea greenthread, Slender thelesperma, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Tonestus lyallii (A.Gray) A.Nelson, Lyall's goldenweed, Lyall's haplopappus, Synonyms: Haplopappus lyallii A. Gray, Native, Uncommon, Photos Phytoimages, USDA_Plants

• Tonestus pygmaeus (Torr. & A.Gray) A.Nelson, Pygmy goldenweed, Synonyms: Haplopappus pygmaeus (Torr. & A. Gary) A. Gray, Native, Common, Photos Phytoimages, USDA_Plants

• Townsendia exscapa (Richardson) Porter, Stemless Easter daisy, Native, Common, Photos Phytoimages, USDA_Plants

• Townsendia grandiflora Nutt., Largeflower Easter daisy, Largeflower townsend daisy, Native, Larimer Co., Photos Phytoimages, USDA_Plants

• Townsendia hookeri Beaman, Hooker's Easter daisy, Hooker's townsend daisy, Hooker's townsend-daisy, Hooker's townsendia, Native, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Tragopogon dubius Scop., Western salsify, Introduced, Uncommon, Photos Phytoimages, USDA_Plants

• Tragopogon porrifolius L., Salsify, Vegetable oyster, Introduced, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Tragopogon pratensis L., Meadow salsify, Jack-go-to-bed-at-noon, Introduced, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Tripleurospermum inodorum (L.) Sch. Bip., Scentless chamomile, Synonyms: Tripleurospermum perforata (Merat) M. Lainz, Matricaria maritima L, Matricaria perforata Merat, Introduced, Abundance - Unknown, Photos Phytoimages, USDA_Plants

• Verbesina encelioides (Cav.) A. Gray ssp. exauriculata (B. L. Rob. & Greenm.) J. R. Coleman, Golden crownbeard, Introduced, Larimer Co., Photos Phytoimages, USDA_Plants