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187k. Asteraceae Martinov tribe Astereae Cassini, J. Phys. Chim. Hist. Nat. Arts. 88: 195. 1819.
Annuals, biennials, perennials, subshrubs, shrubs, or trees. Leaves usually cauline, sometimes mostly basal; alternate [opposite, whorled]; usually petiolate, sometimes sessile; margins entire or dentate to pinnatifid (often gland-dotted, especially in xerophytes). Heads homogamous (discoid; unisexual in Baccharis) or heterogamous (disciform or radiate), usually in corymbiform, paniculiform, racemiform, or spiciform arrays, sometimes borne singly. Calyculi 0. Phyllaries persistent or falling, usually in 3–5+ series (usually in spirals, sometimes in vertical ranks), distinct, unequal, and herbaceous to chartaceous or scarious or margins and/or apices notably scarious, sometimes in 1–2 series, distinct, subequal, and herbaceous with margins and/or apices barely to notably scarious. Receptacles usually flat to conic, sometimes concave, usually epaleate, rarely paleate (often foveolate, socket margins often fimbrillate; paleate in Eastwoodia and Rigiopappus). Ray florets 0 or in 1(–2+) series, usually pistillate, rarely neuter or styliferous and sterile; corollas usually yellow, cyanic, or white (laminae sometimes very reduced, e.g., Conyza spp.). Peripheral (pistillate) florets 0 or (in disciform heads) in 1–3+ series; corollas usually present, usually yellow, sometimes white, ochroleucous, or reddish to cyanic. Disc (inner) florets usually bisexual and fertile, rarely functionally staminate (e.g., Benitoa); corollas usually yellow, sometimes white, ochroleucous, or cyanic, actinomorphic, not 2-lipped, lobes (4–)5; anther bases obtuse or rounded, not tailed, apical appendages usually triangular to linear, sometimes none; styles abaxially glabrous and smooth or papillate (distally), branches ± linear, adaxially stigmatic in 2 lines from bases to apices or appendages, appendages usually deltate to lanceolate (abaxially papillate to hispidulous, adaxially smooth, glabrous). Cypselae monomorphic or dimorphic within heads, usually ± columnar to prismatic and 5-ribbed, sometimes compressed and 2-ribbed, rarely beaked, bodies smooth, muricate, ribbed, or rugulose (glabrous or hairy, hairs often glandular); pappi (rarely 0) usually persistent, usually of barbellulate to barbellate bristles in (1–)2–3+ series, sometimes of scales (scales sometimes aristate), rarely of both scales and bristles or of awns.
Genera 170, species 2800+ (77 genera, 719 species in the flora): almost worldwide, mostly temperate.
The classification and phylogeny of tribe Astereae has been the object of recent work, both morphologic (K. Bremer 1994; G. L. Nesom 1994, 2000) and molecular (notably the seminal paper by R. D. Noyes and L. H. Rieseberg 1999). Noyes and Rieseberg showed that most genera present in North America belong to a single monophyletic clade, called the North American clade. A series of subsequent studies done in various generic groups or subtribes led to a redefinition of many genera (see literature cited in each genus) and to the transfer of species between genera. The current treatment of the tribe reflects much of these novelties, many presented in a floristic work for the first time. Nesom and H. Robinson (unpubl.) present a worldwide overview of the classification of the tribe. Large genera such as Erigeron, Symphyotrichum, and Solidago all originated on the continent and subsequently spread to Eurasia or South America. A few genera entered North America from neighboring continents, such as Aster in the strict sense (from Eurasia) or Baccharis (from Central America). A majority of Astereae genera in the flora of North America are endemic to the continent (more so if Mexico were included).
The generic order of the present treatment attempts to reflect the phylogenetic relationships established in recent molecular phylogenetic work.
SELECTED REFERENCES Anderson, L. C. and J. B. Creech. 1975. Comparative leaf anatomy of Solidago and related Asteraceae. Amer. J. Bot. 62: 486–493. Beck, J. B. et al. 2004. Is subtribe Solidagininae (Asteraceae) monophyletic? Taxon 53: 691–698. Brouillet, L., L. E. Urbatsch, and R. P. Roberts. 2004. Tonestus kingii and T. aberrans are related to Eurybia and the Machaerantherinae (Asteraceae: Astereae) based on nrDNA (ITS and ETS) data: Reinstatement of Herrickia and a new genus, Triniteurybia. Sida 21: 889–900. Cronquist, A. and D. D. Keck. 1957. A reconstitution of the genus Machaeranthera. Brittonia 9: 231–239. Fiz, O., V. Valcárcel, and P. Vargas. 2002. Phylogenetic position of Mediterranean Astereae and character evolution of daisies (Bellis, Asteraceae) inferred from nrDNA ITS sequences. Molec. Phylogen. Evol. 25: 157–171. Hall, H. M. 1928. The genus Haplopappus: A phylogenetic study in the Compositae. Publ. Carnegie Inst. Wash. 389. Hartman, R. L. 1976. A Conspectus of Machaeranthera (Compositae: Astereae) and a Biosystematic Study of the Section Blepharodon. Ph.D. dissertation. University of Texas. Hartman, R. L. 1990. A conspectus of Machaeranthera (Asteraceae: Astereae). Phytologia 68: 439–465. Jones, A. G. 1980. A classification of New World species of Aster (Asteraceae). Brittonia 32: 230–239. Jones, A. G. and D. A. Young. 1983. Generic concepts of Aster (Asteraceae): A comparison of cladistic, phenetic and cytological approaches. Syst. Bot. 8: 71–84. Kapoor, B. M. and J. R. Beaudry. 1966. Studies on Solidago. VII. The taxonomic status of the taxa Brachychaeta, Brintonia, Chrysoma, Euthamia, Oligoneuron, and Petradoria in relation to Solidago. Canad. J. Genet. Cytol. 8: 422–443. Lane, M. A. 1982. Generic limits of Xanthocephalum, Gutierrezia, Amphiachyris, Gymnosperma, Greenella, and Thurovia. (Compositae: Astereae). Syst. Bot. 7: 405–416. Lane, M. A. et al. 1996. Relationships of North American genera of Astereae, based on chloroplast DNA restriction site data. In: D. J. N. Hind et al., eds. 1996. Proceedings of the International Compositae Conference, Kew, 1994. 2 vols. Kew. Vol. 1, pp. 49–77. Morgan, D. R. 1997. Reticulate evolution in Machaeranthera (Asteraceae). Syst. Bot. 22: 599–615. Morgan, D. R. 2003. nrDNA external transcribed spacer (ETS) sequence data, reticulate evolution, and the systematics of Machaeranthera (Asteraceae). Syst. Bot. 28: 179–190. Morgan, D. R. and R. L. Hartman. 2003. A synopsis of Machaeranthera (Asteraceae: Astereae), with recognition of segregate genera. Sida 20: 1837–1416. Morgan, D. R. and B. B. Simpson. 1992. A systematic study of Machaeranthera (Asteraceae) and related groups using restriction site analysis of chloroplast DNA. Syst. Bot. 17: 511–531. Nesom, G. L. 1991b. A phylogenetic hypothesis for the goldenasters (Asteraceae: Astereae). Phytologia 71: 136–151. Nesom, G. L. 1993b. Taxonomic infrastructure of Solidago and Oligoneuron (Asteraceae: Astereae) and observations on their phylogenetic position. Phytologia 75: 1–44. Nesom, G. L. 1994. Subtribal classification of the Astereae (Asteraceae). Phytologia 76: 193–274. Nesom, G. L. 1994b. Review of the taxonomy of Aster sensu lato (Asteraceae: Astereae), emphasizing the New World species. Phytologia 77: 141–297. Nesom, G. L. 1997. Taxonomic adjustments in North American Aster sensu latissimo (Asteraceae: Astereae). Phytologia 82: 281–288. Nesom, G. L. 2000. Generic Conspectus of the Tribe Astereae (Asteraceae) in North America, Central America, the Antilles, and Hawaii. Fort Worth. [Sida Bot. Misc. 20.] Noyes, R. D. 2000. Biogeographical and evolutionary insights on Erigeron and allies (Asteraceae) from ITS sequence data. Pl. Syst. Evol. 220: 93–114. Noyes, R. D. and L. H. Rieseberg. 1999. ITS sequence data support a single origin for North American Astereae (Asteraceae) and reflect deep geographic divisions in Aster s.l. Amer. J. Bot. 86: 398–412. Ruffin, J. 1974. A taxonomic evaluation of the genera Amphiachyris, Amphipappus, Greenella, Gutierrezia, Gymnosperma, Thurovia, and Xanthocephalum (Compositae). Sida 5: 301–333. Ruffin, J. 1977. Palynological survey of the genera Amphiachyris, Amphipappus, Greenella, Gutierrezia, Gymnosperma, and Xanthocephalum (Compositae). Contr. Gray Herb. 207: 117–131. Semple, J. C. and L. Brouillet. 1980. A synopsis of North American asters: The subgenera, sections and subsections of Aster and Lasallea. Amer. J. Bot. 67: 1010–1026. Semple, J. C., S. B. Heard, and L. Brouillet. 2002. Cultivated and Native Asters of Ontario (Compositae: Astereae). Aster L. (Including Asteromoea Blume, Diplactis Raf. and Kalimeris (Cass.) Cass.), Callistephus Cass., Galatella Cass., Doellingeria Nees, Oclemena E. L. Greene, Eurybia (Cass.) S. F. Gray, Canadanthus Nesom, and Symphyotrichum Nees (Including Virgulus Raf.). Waterloo. [Univ. Waterloo Biol. Ser. 41.] Semple, J. C. and J. L. A. Hood. 2005. Pappus variation in North American Asters. I. Double, triple and quadruple pappus in Symphyotrichum and related aster genera (Asteraceae: Astereae). Sida 21: 2141–2159. Semple, J. C., G. S. Ringius, and J. J. Zhang. 1999. The Goldenrods of Ontario: Solidago L. and Euthamia Nutt., ed. 3. Waterloo. [Univ. Waterloo Biol. Ser. 39.] Semple, J. C. and L. Tebby. 1999. A cladistic analysis of subtribe Chrysopsidinae (Asteraceae: Astereae). In: International Botanical Congress. [1999.] Abstracts. XVI International Botanical Congress, St. Louis, USA, August 1–7, 1999. [St. Louis.] Abstr. 2852, poster 401. Solbrig, O. T. 1960. The status of the genera Amphiachyris, Amphipappus, Greenella, Gutierrezia, Gymnosperma, and Xanthocephalum (Compositae). Rhodora 62: 43–53. Suh, Y. and B. B. Simpson. 1990. Phylogenetic analysis of chloroplast DNA in North American Gutierrezia and related genera (Asteraceae: Astereae). Syst. Bot. 660–670. Turner, B. L. 1987b. Taxonomic study of Machaeranthera, sections Machaeranthera and Hesperastrum (Asteraceae). Phytologia 62: 207–266. Urbatsch, L. E., R. P. Roberts, and V. Karaman. 2003. Phylogenetic evaluation of Xylothamia, Gundlachia, and related genera (Asteraceae, Astereae) based on ETS and ITS nrDNA sequence data. Amer. J. Bot. 90: 634–649. Xiang, C. and J. C. Semple. 1996. Molecular systematic study of Aster sensu lato and related genera (Asteraceae: Astereae) based on chloroplast DNA restriction site analyses and mainly North American taxa. In: D. J. N. Hind et al., eds. 1996. Proceedings of the International Compositae Conference, Kew, 1994. 2 vols. Kew. Vol. 1, pp. 393–423. Zanowiak, D. J. 1991. An Analysis of Systematic and Phyletic Relationships within Baccharidinae (Asteraceae: Astereae). Ph.D. dissertation. Texas A&M University. Zhang, J. J. 1996. A Molecular Biosystematic Study on North American Solidago and Related Genera (Asteraceae: Astereae) Based on Chloroplast DNA RFLP Analysis (Phylogenetics). Ph.D. dissertation. University of Waterloo.
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Key A Trees, shrubs (sometimes clambering, sprawling, or vinelike), or subshrubs
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| 1 |
Phyllaries unequal and disposed in vertical ranks |
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(2) |
| + |
Phyllaries equal or unequal and disposed in spirals |
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(7) |
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| 2 (1) |
Heads radiate |
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(3) |
| + |
Heads discoid |
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(4) |
| |
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| 3 (2) |
Leaves cauline, blades 1-nerved (sometimes with 1–2 fainter lateral pairs) |
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161 Chrysoma (in part), p. 105 |
| + |
Leaves basal and cauline, blades 3–5-nerved (veins raised, parallel) |
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168 Petradoria (in part), p. 171 |
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| 4 (2) |
Leaves basal and cauline, blades 3-nerved; heads in glomerate clusters grouped in flat-topped, corymbiform arrays; phyllaries yellowish, sometimes green distally |
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157 Bigelowia, p. 95 |
| + |
Leaves cauline, blades 1-nerved (sometimes with 1–2 fainter lateral pairs); heads (sometimes clustered) in paniculiform, corymbiform, or cymiform arrays, or borne singly; phyllaries stramineous, tan, or green, green or purplish distally |
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(5) |
| |
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| 5 (4) |
Leaf faces gland-dotted (in pits); heads in dense, cymiform arrays |
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161 Chrysoma (in part), p. 105 |
| + |
Leaf faces gland-dotted (sessile) or stipitate-glandular; heads borne singly or in condensed, cymiform clusters, grouped in paniculiform or corymbiform arrays, or in congested, cymiform to corymbiform arrays |
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(6) |
| |
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| 6 (5) |
Heads in congested, cymiform to corymbiform arrays; disc florets 4–15; cypselae oblong to obconic |
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171 Lorandersonia (in part), p. 177 |
| + |
Heads borne singly or in condensed, cymiform clusters grouped in paniculiform or corymbiform arrays; disc florets (2–)5–6(–40); cypselae subcylindric |
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175 Chrysothamnus (in part), p. 187 |
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| 7 (1) |
Trees, shrubs (sometimes clambering, sprawling, or vinelike) |
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(8) |
| + |
Subshrubs |
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(19) |
| |
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| 8 (7) |
Plants unisexual, often glutinous; heads discoid |
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140 Baccharis (in part), p. 23 |
| + |
Plants bisexual, sometimes glutinous, gland-dotted, or stipitate-glandular; heads radiate, discoid, or disciform |
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(9) |
| |
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| 9 (8) |
Heads discoid or disciform |
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(10) |
| + |
Heads radiate |
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(14) |
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| 10 (9) |
Heads disciform (pistillate florets 4–9), in compact glomerules grouped in terminal corymbiform arrays; disc corollas orange-yellow; pappi 0, or minute crowns |
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156 Gymnosperma, p. 94 |
| + |
Heads discoid, borne singly, or in clusters grouped in cymiform or racemiform arrays, or in cymiform, spiciform, racemiform, paniculiform, or corymbiform arrays; disc corollas yellow or white; pappi of scales or bristles |
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(11) |
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| 11 (10) |
Cypselae 3–4-angled, strigoso-sericeous; pappi of (5–8) linear-lanceolate scales |
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166 Eastwoodia, p. 169 |
| + |
Cypselae prismatic, terete, subterete, or compressed, glabrous or ± densely hairy; pappi of bristles |
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(12) |
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| 12 (11) |
Stems not resinous; leaves entire or toothed (teeth sometimes bristly); heads usually in spiciform, racemiform, narrowly paniculiform, or corymbiform arrays, rarely borne singly;phyllaries not resinous; pappi reddish brown |
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206 Hazardia (in part), p. 445 |
| + |
Stems resinous; leaves entire; heads borne singly or in clusters (at branch tips), and/or in usually cymiform or racemiform, sometimes paniculiform or thyrsiform arrays; phyllaries resinous; pappi whitish tan to reddish |
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(13) |
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| 13 (12) |
Leaves filiform, linear, lanceolate, or spatulate (adaxially sulcate, concave or plane), margins sometimes undulate or crisped; heads borne singly or in usually cymiform or racemiform, sometimes paniculiform or thyrsiform arrays; involucres hemispheric or obconic; disc florets 4–70, corolla lobes equal (cypselae 2–10 mm) |
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148 Ericameria (in part), p. 50 |
| + |
Leaves filiform, margins flat or involute; heads in clusters at branch tips, grouped in cymiform or racemiform arrays; involucres turbinate; disc florets 3–7, corolla lobes unequal (cypselae 1–3 mm) |
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151 Gundlachia, p. 84 |
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| 14 (9) |
Shrubs clambering, sprawling, or vinelike; rays pale rose-purple to pale pink (Atlantic coastal plain) |
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211 Ampelaster, p. 460 |
| + |
Shrubs not clambering, sprawling, or vinelike; rays yellow or white |
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(15) |
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| 15 (14) |
Plants spinescent (at least with age); corollas yellow |
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(16) |
| + |
Plants not spinescent; corollas white or yellow |
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(17) |
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| 16 (15) |
Leaves sometimes in axillary fascicles; heads borne singly or in loose, corymbiform arrays; ray florets 5–14; disc florets 13–80, bisexual, fertile; pappi of barbellate scales |
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173 Acamptopappus, p. 184 |
| + |
Leaves not in axillary fascicles; heads (2–4) in glomerate clusters, these grouped in corymbiform arrays; ray florets 1–2; disc florets 3–7, functionally staminate; pappi of flattened bristles (those of discs sometimes undulate to twisted) |
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174 Amphipappus, p. 186 |
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| 17 (15) |
Leaves entire or toothed (teeth sometimes bristly; bases clasping or subclasping); heads usually in racemiform, narrowly paniculiform, or corymbiform arrays, rarely borne singly; phyllaries in 5–9 series; cypselae fusiform to deltoid, 4–5-nerved; pappi reddish brown |
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206 Hazardia (in part), p. 445 |
| + |
Leaves entire (bases not clasping); heads borne singly or in cymiform or racemiform (sometimes paniculiform or thyrsiform) arrays; phyllaries in 3–6+ series; cypselae ellipsoid to obconic or obovoid, ± 5–12-ribbed or -nerved; pappi whitish tan to reddish |
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(18) |
| |
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| 18 (17) |
Involucres hemispheric, obconic, or cylindric; disc corolla lobes equal; cypselae prismatic |
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148 Ericameria (in part), p. 50 |
| + |
Involucres turbinate; disc corolla lobes unequal; cypselae± turbinate |
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152 Neonesomia, p. 85 Neonesomia, |
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| 19 (7) |
Plants unisexual; heads discoid |
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140 Baccharis (in part), p. 23 |
| + |
Plants bisexual; heads radiate, disciform, or discoid |
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(20) |
| |
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|
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| 20 (19) |
Heads disciform or discoid |
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(21) |
| + |
Heads radiate |
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(26) |
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| 21 (20) |
Stems eglandular; leaves entire |
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(22) |
| + |
Stems gland-dotted or stipitate-glandular; leaves entire, toothed, or pinnatifid |
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(23) |
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| 22 (21) |
Heads borne singly or in cymiform-racemiform arrays; involucres 11–15(–17) mm; florets 4–7; cypselae oblong, 5–6-ribbed, glabrous |
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159 Cuniculotinus, p. 100 |
| + |
Heads borne singly in cymiform arrays; involucres 5–7 mm; florets 12–25+; cypselae narrowly oblong, 8–13-nerved (per face), ± sericeous |
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198 Arida (in part), p. 401 |
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| 23 (21) |
Heads borne singly (at tips of branches) or in corymbiform arrays; cypselae dimorphic (ray ± 3-sided, disc compressed) |
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195 Xanthisma (in part), p. 383 |
| + |
Heads usually in spiciform, racemiform, corymbiform, or cymiform arrays, rarely borne singly; cypselae monomorphic (terete, subterete, or compresssed) |
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(24) |
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| 24 (23) |
Involucres broadly urceolate to hemispheric or globose; phyllaries usually looped to hooked, usually resinous |
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202 Grindelia (in part), p. 424 |
| + |
Involucres campanulate, obconic, turbinate, or cylindric; phyllaries not hooped or hooked, not resinous |
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(25) |
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| 25 (24) |
Basal leaves persistent; heads in compact clusters grouped in corymbiform arrays; involucres 3–9.5 mm; disc corollas goblet-shaped (tubes elongating, elevating throats above involucres at flowering); cypselae obpyramidal, 5–11-ribbed (ribs sometimes thick and resinous), sericeous |
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205 Isocoma, p. 439 |
| + |
Basal leaves withering by flowering; heads in spiciform, racemiform, or cymiform arrays; involucres 11–13 mm; disc corollas ± tubular (tubes not elevating throats); cypselae fusiform to deltoid, 4–5-nerved, glabrous |
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206 Hazardia (in part), p. 445 |
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| 26 (20) |
Rays white, light blue, or purple |
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(27) |
| + |
Rays yellow (sometimes drying red-purple) |
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(32) |
| |
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| 27 (26) |
Plants often thorny (thorns green); leaves usually entire, rarely 1–2-denticulate; heads borne singly or in loose, corymbo-paniculiform arrays; involucres 4.5–7.5 mm; rays white; disc corolla veins orange, resinous |
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190 Chloracantha (in part), p. 358 |
| + |
Plants not thorny; leaves entire, dentate or serrate (teeth spinulose); heads borne singly or in corymbiform arrays; involucres 6–20 mm; rays white, light blue, or purple; disc corolla veins not orange-resinous |
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(28) |
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| 28 (27) |
Cypselae 7–10-nerved, glabrous (Animas River Basin, n New Mexico,s Colorado) |
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192 Herrickia (in part), p. 361 |
| + |
Cypselae 2–7-nerved or -ribbed, hairy |
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(29) |
| |
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| 29 (28) |
Cypselae dimorphic (ray 3-sided, disc compressed), obovoid or oblong |
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195 Xanthisma (in part), p. 383 |
| + |
Cypselae monomorphic (compressed or terete), ovoid, fusiform, cuneiform, or linear |
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(30) |
| |
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|
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| 30 (29) |
Cypselae flattened, 2–(3–4)-nerved; pappi of outer, shorter bristles orscales plus inner, longer bristles |
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150 Ionactis (in part), p. 82 |
| + |
Cypselae ± compressed or not, 4–7-ribbed; pappi of ± unequal bristles (outer not in notably distinct series) |
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(31) |
| |
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| 31 (30) |
Stems glabrous or villous to tomentose, sometimes stipitate-glandular; phyllaries keeled; ray florets bisexual, fertile; cypselae ovoid, fusiform, or linear, 4-nerved, sericeous |
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199 Xylorhiza (in part), p. 406 |
| + |
Stems usually densely white-tomentose, sometimes glabrate or ± stipitate-glandular distally; phyllaries flat; ray florets neuter; cypselae cuneiform or linear, 5–7-ribbed, puberulent to pilose |
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208 Corethrogyne (in part), p. 450 |
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| 32 (26) |
Phyllaries in vertical ranks; heads congested or glomerate, usually in corymbiform or cymiform, sometimes spiciform, arrays |
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(33) |
| + |
Phyllaries in spirals; heads borne singly, 3–6, or glomerate, in flat-topped or multi-storied, corymbiform arrays, or in ± loose corymbiform, racemiform, narrowly paniculiform, or spiciform arrays |
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(34) |
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| 33 (32) |
Leaves basal and cauline (not crowded), 3–5-nerved (veins parallel, raised); heads in glomerules in corymbiform arrays; ray florets 1–3; disc florets functionally staminate, corolla lobes lanceolate; cypselae cylindric, plump orslightly compressed |
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168 Petradoria (in part), p. 171 |
| + |
Leaves cauline (often crowded), usually 1-nerved, sometimes with 1–2 collateral pairs; heads in congested cymiform or corymbiform arrays; ray florets (1–)6–8; disc florets bisexual, fertile; cypselae oblong to obconic or prismatic |
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171 Lorandersonia (in part), p. 177 |
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| 34 (32) |
Involucres usually broadly urceolate, globose, or hemispheric; phyllaries filiform to linear, apices often looped or hooked, faces usually ± resinous |
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202 Grindelia (in part), p. 424 |
| + |
Involucres cylindro-turbinate, turbinate, obconic, campanulate, or hemispheric; phyllaries ovate, lanceolate, oblanceolate, or lanceolate to linear, apices straight or recurved (not looped or hooked), faces sometimes gland-dotted (not resinous). |
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(35) |
| |
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| 35 (34) |
Basal leaves pinnatifid (lobes bristle-tipped); pappi of setiform scales (or basally flattened bristles) |
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195 Xanthisma (in part), p. 383 |
| + |
Basal leaves not pinnatifid; pappi of bristles and/or scales |
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(36) |
| |
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| 36 (35) |
Pappi of scales |
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155 Gutierrezia (in part), p. 88 |
| + |
Pappi of bristles, or of outer, shorter scales plus inner, longer bristles |
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(37) |
| |
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|
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| 37 (36) |
Stems prostrate to erect, mat-forming, branched; leaves cauline (crowded); heads borne singly |
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167 Nestotus, p. 169 |
| + |
Stems erect, not mat-forming, branched or simple; leaves basal and cauline or mostly cauline (then not crowded); heads in spiciform, racemiform, corymbiform, or cymiform arrays, or glomerate and/or pedunculate-solitary in flat-topped or multi-storied, corymbiform arrays |
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(38) |
| |
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| 38 (37) |
Plants rhizomatous; heads usually glomerate, sometimes pedunculate-solitary, in flat-topped or multi-storied, corymbiform arrays |
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158 Euthamia (in part), p. 97 |
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Plants taprooted or fibrous-rooted; heads not glomerate, in spiciform, racemiform, corymbiform, subumbelliform, paniculiform, or cymiform arrays |
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(39) |
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| 39 (38) |
Leaves densely short-woolly (hairs flagelliform); heads in subumbelliform to paniculiform arrays; pappi of outer, triangular scales plus inner bristles in (2–)3 series; e North America |
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182 Chrysopsis (in part), p. 213 |
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Leaves glabrous, sparsely puberulent or stipitate-glandular, or scabroso-hispidulous (hairs not flagelliform); heads in spiciform, racemiform, corymbiform, or cymiform arrays, sometimes borne singly; pappi of unequal bristles in 1–4 series; w North America |
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(40) |
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| 40 (39) |
Leaves basal and cauline, margins entire; involucres cylindro-turbinate; ray florets 5–8; cypselae narrowly oblong, 8-nerved, moderately strigose |
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165 Columbiadoria, p. 167 |
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Leaves mostly cauline, margins serrate (teeth bristle-tipped); involucres campanulate; ray florets 5–18; cypselae fusiform to deltoid, 4–5-nerved, glabrous |
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206 Hazardia (in part), p. 445 |
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List of Keys
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List of lower taxa
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Treatments in Other Floras @ www.efloras.org
Other Databases
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