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187. Asteraceae Martinov

Composite Family

Theodore M. Barkley†, Luc Brouillet, John L. Strother

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 (styles usually not branched in functionally staminate florets), style branches apically truncate or appendaged beyond the stigmatic bands or lines, appendages usually papillate to hirsute distally on abaxial (or abaxial and adaxial) faces. Fruits (technically cypselae, historically called achenes) usually dry with relatively thick, tough pericarps, sometimes beaked (rostrate) and/or winged (alate), often dispersed with aid from pappi. Seeds 1 per fruit, exalbuminous; embryos straight.

Genera ca. 1500, species ca. 23,000 (418 genera, 2413 species in the flora): nearly worldwide, especially rich in numbers of species and/or in numbers of plants in arid and semiarid regions of subtropical and lower to middle temperate latitudes.

Asteraceae (Compositae, "composites," or "comps") have long been recognized as a natural group, and circumscription of the group has never been controversial (although some authors have divided the traditional family into three or more families). A. Cronquist (1981) placed Asteraceae as the only family in the order Asterales within subclass Asteridae, associated with the Gentianales, Rubiales, Dipsacales, and Calycerales and relatively distant from Campanulales. On recent molecular phylogenetic data, the Angiosperm Phylogeny Group (2003; see references there for details; classification abbreviated APGII hereafter) has suggested that Asteraceae are better treated as part of a more widely defined Asterales within the asterids II informal clade (or campanulid clade; see W. S. Judd and R. G. Olmstead 2004). Judd and Olmstead summarized the higher-order relationships of Asteraceae as follows (in order of decreasing inclusiveness; synapomorphies in parentheses): asterids (ovules unitegmic and tenuinucellate, iridoid chemistry); core asterids (sympetaly, stamen number equal to petal number, stamen epipetaly, mostly 2–3-carpellate gynoecia); campanulids (early sympetaly), comprising eight unassigned families plus Aquifoliales, which is sister to Dipsacales, Apiales, and Asterales (last three sharing frequently inferior ovaries, polyacetylenes); and Asterales, which appears to be sister to Dipsacales-Apiales (K. Bremer et al. 2004). The order Asterales (valvate petals, lack of apotracheal parenchyma, storage of inulin, ellagic acid present, and, possibly, the presence of a plunger or brush pollen presentation mechanism) now includes the following families (fide APGII): Alseuosmiaceae, Argophyllaceae, Calyceraceae, Campanulaceae (optionally including Lobeliaceae), Goodeniaceae, Menyanthaceae, Pentaphragmaceae, Phellinaceae, Rousseauaceae, and Stylidiaceae. Within Asterales, Asteraceae is part of a clade (corollas with more or less fused lateral veins joining midvein near lobe apices, thick integuments, no endosperm haustorium) with the Menyanthaceae (cosmopolitan with Southern Hemisphere genera) basal to a more nested clade (inferior ovaries, possibly connate anthers, pollen exine with bifurcating columellae) comprising Asteraceae, Goodeniaceae (mainly Australia), and Calyceraceae (South America), the last being the immediate sister to Asteraceae (highly modified, persistent calyces, corolla venation patterns, unilocular and uniovulate gynoecia, pollen with intercolpar depressions, specialized fruits). Aggregation of flowers into heads with involucres appears to have been a parallel phenomenon in Calyceraceae and Asteraceae, given the determinate nature of the former and indeterminate (racemose) organization of the latter. Some traits typical of Asteraceae predate evolution of the family as a distinct clade. Relationships of Asteraceae and Calyceraceae have been discussed by M. H. G. Gustafsson and Bremer (1995). Synapomorphies of the Asteraceae clade include: calyces modified to structures called pappi, anthers connate (forming tubes) and styles modified to function as brushes in a specialized pollen presentation mechanism, ovaries each containing a single basal ovule, and production of sesquiterpene lactones.

K. Bremer et al. (2004) gave an Early Cretaceous origin for the Asteridae and the basal campanulids, and a Late Cretaceous origin for the Asterales. Bremer and M. H. G. Gustafsson (1997) also hypothesized a Late Cretaceous ancestry of Asterales in East Gondwanaland (Australasia), with later expansion into West Gondwanaland (South America-Antarctica), where the Asteraceae originated before the final separation of South America and Antarctica. Similarly, M. L. DeVore and T. F. Stuessy (1995) argued that the close relationships of Asteraceae to Goodeniaceae and Calyceraceae, plus the basal position of Barnadesioideae K. Bremer & R. K. Jansen (Asteraceae), indicated a South America-Antarctica-Australia origin for the complex. After reviewing previous hypotheses, they proposed a late Eocene origin for the complex and suggested a South American origin for the Asteraceae based on the basal position of the South American Barnadesioideae (see also Stuessy et al. 1996, on Barnadesioideae origin in southern South America in the Oligocene) and their sister relationship to Calyceraceae. Fossil pollen data (both Mutisieae and Asteroideae types—notably Heliantheae in the broad sense—among earliest reports) reviewed by A. Graham (1996) appear to indicate an Eocene origin for Asteraceae in South America, with migration to North America at least by the Oligocene, possibly as early as the late Eocene. More recently, M. S. Zavada and S. E. de Villiers (2000; and references therein) reported Asteraceae pollen (assignable to Mutisieae in the broad sense) from the Paleocene-Eocene of South Africa, suggesting an earlier, West Gondwana (southern Africa or Australia) origin for the family. Such data indicate that some tribes of Asteraceae may have arrived in North America via long-distance dispersal or island hopping well before closure of the isthmus of Panama. They also have a bearing on the possible times of radiation of some tribes in North America, particularly Heliantheae in the broad sense and Eupatorieae, which originated in the continent (including Mexico and parts of Central America), and those that came to North America from or through South America such as Mutisieae, Vernonieae, some Plucheeae, and Astereae. Other tribes, such as Cynareae, Cichorieae, some Gnaphalieae, and Anthemideae, may have reached North America from Eurasia, possibly via Beringia (or as Amphi-Atlantic disjuncts), at a later time.

The bases of a tribal classification within Asteraceae were established in the nineteenth century, primarily through the work of H. Cassini (especially in articles scattered through the 61 volumes of F. Cuvier 1816–1845; Cassini included synopses of his tribes as part of his entry for Zoegea, i.e., zyégée in French; the articles have been collected in three volumes by R. M. King and H. W. Dawson 1975), C. F. Lessing (1832), A. P. de Candolle (1828–1838, 1836–1838), and, particularly, G. Bentham (1873). In the twentieth century, the tribal system of Cassini, as elaborated by Bentham, was widely followed with only slight modifications (see S. Carlquist 1976; A. Cronquist 1955, 1977; C. Jeffrey 1978; G. Wagenitz 1976b; see also J. Small 1919 and, for alternate views on Heliantheae-Eupatorieae, H. Robinson 1996).

A molecular phylogenetic study by R. K. Jansen and J. D. Palmer (1987) established that a South American clade (later named Barnadesioideae) is basal within Asteraceae. Both cladistic morphologic analyses (e.g., K. Bremer 1994, 1996) and mostly chloroplast-DNA molecular phylogenies (e.g., Jansen et al. 1991, 1992; K. J. Kim et al. 1992; Kim and Jansen 1995; R. J. Bayer and J. R. Starr 1998; P. K. Eldenäs et al. 1999; B. G. Baldwin et al. 2002) have deepened our knowledge of tribal interrelationships within Asteraceae and led to the recent proposal of a phylogenetic classification for the family with 10 subfamilies and 35 tribes (J. L. Panero and V. A. Funk 2002).

Treatment of Asteraceae here differs from some of the recently proposed classifications in that some groups continue to be traditionally circumscribed (e.g., Mutisieae in the broad sense, Heliantheae in the broad sense, including Helenieae and excluding Eupatorieae). Where appropriate and so far as practicable, new taxonomies are acknowledged in our discussions of individual tribes (which see). In North America, the following subfamilies and tribes, as defined by J. L. Panero and V. A. Funk (2002), are represented (tribes with no native representatives are marked by asterisks): Mutisioideae-Mutisieae in the strict sense, Gochnatioideae-Gochnatieae, and Hecastocleioideae-Hecastocleideae (all included in Mutisieae here, which see), Carduoideae (Cardueae = Cynareae), Cichorioideae (*Arctoteae, Cichorieae, Vernonieae), and Asteroideae [Senecioneae, *Calenduleae, Gnaphalieae, Anthemideae, Astereae, Plucheeae, *Inuleae, Eupatorieae, and the following segregates of Heliantheae in the broad sense (all treated here within or as subtribes of a fairly traditionally circumscribed Heliantheae): Bahieae, Chaenactideae, Coreopsideae, Helenieae, Heliantheae in the strict sense, Madieae, *Millereae, Perityleae, Polymnieae, and Tageteae)].

Asa Gray produced the first broadly influential floristic synthesis of North American Asteraceae. Other authors who made important contributions to floristics of North American Asteraceae in the nineteenth and first half of the twentieth centuries were S. F. Blake, N. L. Britton, R. S. Ferris, M. L. Fernald, E. L. Greene, H. M. Hall, M. E. Jones, D. D. Keck, P. A. Rydberg, J. K. Small, and S. Watson. Some of those authors had narrower concepts of genera and species than had their predecessors and they freely recognized new taxa in Asteraceae (mostly genera and species). Floristics of North American Asteraceae in the second half of the twentieth century was especially influenced by A. Cronquist (e.g., 1955, 1980, 1994; H. A. Gleason and Cronquist 1991), who usually favored traditional generic circumscriptions.

In the last 20 years or so, developments in molecular systematics have led to revisions of generic limits in some tribes of Asteraceae and, sometimes, to a return to generic concepts that had been suggested earlier but largely ignored. More or less worldwide, taxonomies in some tribes or parts of tribes have included segregate genera that have been revived or newly published. Most of the innovations will be summarized in the forthcoming Asterales volume of K. Kubitzki et al. (1990+). The generic circumscriptions adopted here incorporate recent taxonomic findings relevant to North America, insofar as our contributors have accepted them. As a result, many of the genera treated herein have never been presented in a major flora before, and some species are included within genera with which they were not associated traditionally. Thus, the Flora brings together much new knowledge and many new names. In most instances, circumscriptions of species have turned out to be conventional. So far as practicable, recently named species from North America have been accounted for within relevant treatments herein.

With 418 genera and 2413 species (Table 1), Asteraceae is, numerically, the largest family in the flora of North America north of Mexico. Members of the family are found in diverse habitats, from the High Arctic tundra and polar deserts to the Sonoran warm-desert scrub, and from alpine habitats to salt marshes. Asteraceae are particularly conspicuous elements of warm-desert and intermountain grasslands, as well as of desert scrubs, notably the intermountain desert scrub where Artemisia dominates (M. G. Barbour and N. L. Christensen 1993). Among other conspicuous species, members of Solidago and Symphyotrichum form a very showy part of the fall flowering in eastern North America, and members of Heliantheae sometimes produce striking displays in the American West (e.g., Gaillardia spp., Lasthenia spp., members of Madiinae).

Much has been published, not only on systematics (at various levels), but on biology, chemistry, and economic and medical uses of Asteraceae worldwide, particularly in proceedings (from conferences and symposia) edited by V. H. Heywood et al. (1977), T. J. Mabry and G. Wagenitz (1990), and D. J. N. Hind et al. (1995, 1996).

Relatively few North American species of Asteraceae are economically important or widely used ethnobotanically. The only major Asteraceae crop of North American origin is the sunflower, Helianthus annuus, which is valued for its seed oil and is appreciated in the horticultural trade. Other crop plants from native species worth mention are Helianthus tuberosus, the Jerusalem artichoke, and Parthenium argentatum, the guayule, a source of rubber. Echinacea spp. are touted as health plants. Members of several genera of Asteraceae native to the flora are grown for their ornamental value, notably species of Coreopsis (tickseeds), Echinacea (coneflowers), Helianthus (sunflowers), Liatris (blazingstars and gayfeathers), Rudbeckia (black-eyed Susans), Solidago (goldenrods), and Symphyotrichum ("asters" of the trade).

Many species of Asteraceae have been introduced into North America, mainly from Europe and Asia, some deliberately for medicines, foods, or horticulture, others accidentally (often with seeds or other agricultural products or by other means). Few, if any, of the introduced taxa are thought to be noxious at the continental level, but some (e.g., Acroptilon) are considered noxious in large parts of their ranges within the flora. Taraxacum officinale is a common lawn weed that (in terms of dollars spent and herbicides applied in weed control) has an economic and ecologic impact disproportionate to the actual harm it causes; other weedy introduced Asteraceae are of little economic consequence. Some native Asteraceae are toxic to cattle and other livestock and are therefore considered weeds. And some native species of open habitats (e.g., Symphyotrichum pilosum) are often considered weeds because they invade fields left fallow. Ragweeds (especially Ambrosia artemisiifolia and A. trifida) range over nearly the whole continent and their wind-blown pollens cause late-summer allergic reactions (hayfever) for a large number of people. Because ragweeds have a large impact on human health, they have a significant, negative economic impact.

In contrast to Orchidaceae, for which a wealth of excellent, well-illustrated popular books are available, few popular field guides on Asteraceae of North America have been published. The guide by T. M. Antonio and S. Masi (2001) deserves notice for its maps, color photographs, and useful information.

Composites (members of Asteraceae) share some unusual morphologic traits and some morphologic terms are used in particular ways as applied here to them.

For treatments of composites here, "perennials" are herbaceous and differ from annuals and biennials in living longer than two years and differ from subshrubs, shrubs, and trees in not developing woody aerial stems.

In most composites, leaf venation comprises a midrib plus more or less equal lateral nerves or veins; such leaves are described as pinnately nerved. Venation in leaf blades of some composites often consists of a midrib plus relatively strong lateral veins that diverge at or just distal to bases of blades. Such leaves are described as 3-nerved, 3(–5)-nerved, 5-nerved, etc., and, as appropriate, the phrases "from bases" or "distal to bases" may be added for clarification.

Composites often have subsessile to sessile or sunken glandular hairs that consist of multicellular bases supporting globular elements that usually contain resinous or sticky substances. Such structures have been called glands, glandular hairs, glandular trichomes, punctae, resin dots, and so on. Sometimes, the glands are embedded in epidermal depressions or pits. Epidermes with glands more or less sunk into or embedded within the surface have been called glandular-punctate and/or punctate-glandular. The glands may be colorless (translucent) or yellowish to dark brown or orange and are sometimes more prominent on dried specimens than in living plants. In keys and descriptions here, gland-dotted refers to the presence of such glandular hairs, whether sessile or in depressions or pits (as appropriate, "in pits" or "sessile" may be added for clarification).

Inflorescences of composites are called heads (or capitula, sing. capitulum). Heads may be borne singly (i.e., not clearly associated with other heads on the same plant) or associated in arrays. The arrays of heads on composites correspond to arrays of individual flowers (inflorescences) on plants of other families; arrays of heads are sometimes called capitulescences. Terms for architectural structures of arrays of heads are parallel to terms for kinds of inflorescences: cymiform, corymbiform, paniculiform, racemiform, spiciform, thyrsiform, etc.

In radiate heads, peripheral florets (ray florets) in one or more series have corollas with zygomorphic limbs and may be pistillate, or styliferous and sterile, or neuter; the central florets (disc florets) in radiate heads have ± actinomorphic corollas and may be bisexual or functionally staminate. In liguliflorous heads, all florets are bisexual and (usually) fertile and have zygomorphic corollas (ligulate florets); liguliflorous heads are characteristic of Cichorieae and are found in no other composites. In discoid heads, all florets have ± actinomorphic corollas and all are either bisexual and fertile or all are either functionally staminate or pistillate (in monoecious or dioecious taxa, e.g., Baccharis spp.). In disciform heads, all florets have ± actinomorphic corollas, and peripheral florets (in one or more series) are usually pistillate and usually have relatively slender (often filiform) corollas. Such peripheral pistillate florets are generally thought to be derived by reduction from ray florets, and plants with disciform heads are generally thought to be derived from ancestors with radiate heads. The central florets of disciform heads are usually bisexual, sometimes functionally staminate. By tradition and for simplicity, both the peripheral, pistillate florets and the inner, bisexual or functionally staminate florets in disciform heads may be referred to as "disc" florets. In radiant heads, all florets have ± actinomorphic corollas and the peripheral florets usually have much enlarged corollas and may be bisexual, pistillate, or neuter; the central florets of radiant heads are usually bisexual. Some composites have peripheral, bisexual florets with slightly to strongly zygomorphic corollas (e.g., some members of Chaenactis, Lessingia, Thymophylla, et al.); heads of such plants do not quite conform to any of the five types just described and such heads may be referred to as "quasi-radiate" or "quasi-radiant." Some florets in heads of some Mutisieae have 2-lipped corollas and those heads may be called "quasi-radiate" or "quasi-liguliflorous." The term eradiate is used to refer collectively to discoid, disciform, and radiant heads.

Heads with all florets of one sexual form (bisexual, pistillate, or functionally staminate) are called homogamous (discoid and liguliflorous heads are homogamous, some radiant heads may be homogamous) and heads with florets of two or more sexual forms are called heterogamous (radiate and disciform heads are heterogamous, some radiant heads may be heterogamous).

Phyllaries collectively constitute an involucre, usually number 5–21(–50+), usually are unequal (outermost usually shorter than the inner), and usually are arranged ± imbricately (overlapping like shingles) in 3–5(–15+), usually ± spiral series. Sometimes, the phyllaries are ± equal in 1–2 series; they are rarely wanting (e.g., Psilocarphus spp.). Phyllaries may be herbaceous or chartaceous to scarious and are often medially herbaceous with chartaceous to scarious borders and/or apices. The phyllaries "proper" are sometimes immediately subtended by a calyculus (pl. calyculi) of (1–)3–15+ distinct, usually shorter bractlets in 1(–3+) series (e.g., Coreopsis spp., Taraxacum spp.).

Receptacles may bear paleae (i.e., some or all florets are individually subtended by a bractlet called a palea or receptacular bract). Collectively paleae have been called "chaff" and paleate receptacles have been described as "chaffy." Receptacles that bear paleae are referred to as paleate and receptacles that never bear paleae are referred to as epaleate. Epaleate receptacles sometimes bear subulate enations (e.g., some Gaillardia spp.) or bristles or subulate to linear scales (e.g., some Cynareae), or fine hairs (e.g., some Anthemideae). Epaleate receptacles (and paleate receptacles that have shed their paleae) may be smooth or pitted (alveolate, foveolate, etc.).

The terms tube, throat, and limb have been variously used in descriptions of corollas of composites. Here, in ± actinomorphic corollas of bisexual and functionally staminate disc florets, the tube is the part of the corolla proximal to the insertion of the staminal filaments, and the limb is the part that is distal to insertion of the filaments. The limb comprises, proximally, the throat and, distally, the lobes. The distinction between tube and throat hinges on insertion of filaments, not on external morphology.

The relatively flat portion of a corolla of a ligulate floret from a liguliflorous head (i.e., members of Cichorieae) is called a ligule; it terminates in 5 teeth or lobes. The relatively flat portion of a corolla of a ray floret is called a lamina; it terminates in 0–3(–4) teeth or lobes. More or less bilabiate corollas are characteristic of some members of Mutisieae and are seldom found in members of other tribes.

Fruits of composites have been called "achenes" because they resemble true achenes. Achenes are dry, hard, single-seeded fruits derived from unicarpellate, superior ovaries. Ovaries of composites are bicarpellate and inferior. Fruits derived from ovaries of composites are called cypselae (sing. cypsela, a term coined by C. de Mirbel in 1815). Morphology of an ovary of a composite at flowering is often markedly different from the morphology of the mature fruit (cypsela) derived from that ovary. References to cypselae in keys and descriptions here almost always refer to mature fruits, not to ovaries at flowering.

Shapes of cypselae have been used in distinguishing among species, genera, and even subtribes of composites. In most composites, cypselae are ± isodiametric in cross section. In some composites, cypselae are characteristically ± lenticular to elliptic in cross section. Such cypselae are said to be compressed (or laterally flattened) if the longer axis of the cross section is ± parallel to a radius of the head (e.g., Verbesina spp.). Cypselae are said to be obcompressed (or radially flattened) if the shorter axis of the cross section is ± parallel to a radius of the head (e.g., Coreopsis spp.).

In composites, pappi (sing. pappus) are found where calyces are usually found on inferior ovaries; pappi have been shown to be greatly modified calyces. They show a great range of diversity and are often diagnostic for recognition of taxa, especially at rank of genus and below. The forms of individual pappus elements intergrade. For keys and descriptions here, the following distinctions are made: cross sections of bristles and awns are ± circular or polygonal and have the longer diameter of the cross section no more than 3 times the shorter diameter. Pappus elements with "flatter" cross sections (i.e., longer diameter more than 3 times the shorter diameter) are called scales, regardless of relative overall lengths and widths of the elements. As used here, "subulate scale" and "setiform scale" mean much the same as "flattened bristle" of some authors. Pliable to stiff pappus bristles with diameters less than ca. 50 µm are called fine bristles; pliable to stiff bristles with diameters 50–100 µm are called coarse bristles. Rigid pappus elements with ± circular or polygonal cross sections greater than 100 µm in diameter are called awns. Bristles, awns, and scales may be smooth or finely to coarsely barbed or plumose. A scale of a pappus may terminate in one or more bristlelike or awnlike appendages; such scales are said to be aristate.

In keys and descriptions, "pappus" and "pappi" usually refer to structures found on cypselae (mature fruits), not to "immature pappi" of ovaries at flowering. Sometimes pappi of ovaries that do not form fruits (e.g., in functionally staminate florets of some tarweeds) may be taxonomically useful and may be referred to in descriptions and keys.

Following is a synoptic key to tribes into which genera of composites of the flora area are placed. Keys to genera within each tribe will be found in the accounts of the individual tribes. Because some traits in the key to tribes and in keys to genera within tribes may be difficult to assess, we have also provided a key to artificial groups of composites and keys to genera within those artificial groups. Those keys will be found following the key to tribes.

In the following key, "radiate heads" have ray florets; "eradiate heads" lack ray florets and may be disciform, discoid, or radiant. Ray florets have zygomorphic corollas with laminae; the laminae may be showy (as in some species of Helianthus) or inconspicuous (as in some species of Erigeron). Usually, we have included plants with inconspicuous ray laminae in keys to genera of both radiate and eradiate groups.

Some plants have questionably paleate or epaleate receptacles. Epaleate receptacles of some plants are notably pitted and have fimbriate to deeply lacerate pit borders; such receptacles have sometimes been interpreted as paleate. Plants with notably lacerate pit borders are usually keyed here as both paleate and epaleate.

Some plants with pappi of conspicuous bristles often have the bristles subtended by minute, inconspicuous scales. Although such plants technically belong to groups with pappi "wholly, or partially, of awns or scales," they are usually also keyed here in groups characterized as having pappi "wholly of bristles," because the scales are easily overlooked. As well, some pappus elements are borderline between being called subulate or setiform scales or being called "flattened bristles." Consequently, some plants that technically belong to groups with pappi of scales are keyed both in groups with pappi "wholly of bristles" and in groups with pappi "wholly, or partially, of awns or scales."

SELECTED REFERENCES

Antonio, T. M. and S. Masi. 2001. The Sunflower Family in the Upper Midwest.... Indianapolis. Bayer, R. J. and J. R. Starr. 1998. Tribal phylogeny of the Asteraceae based on two non-coding chloroplast sequences, the trnL intron and the trnL/F intergenic spacer. Ann. Missouri Bot. Gard. 85: 242–256. Bentham, G. 1873. Notes on the classification, history, and geographical distribution of Compositae. J. Linn. Soc., Bot 13: 335–577. Bremer, K. 1987. Tribal interrelationships of the Asteraceae. Cladistics 3: 210–253. Bremer, K. 1994. Asteraceae: Cladistics and Classification. Portland. Bremer, K. 1996. Major clades and grades of the Asteraceae. In: D. J. N. Hind et al., eds. 1996. Proceedings of the International Compositae Conference, Kew, 1994. 2 vols. Kew. Vol. 1, pp. 1–7. Carlquist, S. 1966. Wood anatomy of Anthemidae, Ambrosieae, Calenduleae, and Arctotideae (Compositae). Aliso 6(2): 1–23. Carlquist, S. 1976. Tribal interrelationships and phylogeny of the Asteraceae. Aliso 8: 465–492. Cronquist, A. 1955. Compositae. In: C. L. Hitchcock et al. 1955–1969. Vascular Plants of the Pacific Northwest. Seattle. Vol. 5. Cronquist, A. 1955b. Phylogeny and taxonomy of the Compositae. Amer. Midl. Naturalist 53: 478–511. Cronquist, A. 1977. The Compositae revisited. Brittonia 29: 137–153. Cronquist, A. 1980. Asteraceae. In: A. E. Radford et al., eds. 1980+. Vascular Flora of the Southeastern United States. 2+ vols. Chapel Hill. Vol. 1. Cronquist, A. 1994. Asteraceae. In: A. Cronquist et al., eds. 1972+. Intermountain Flora. Vascular Plants of the Intermountain West, U.S.A. 5+ vols. in 6+. New York and London. Vol. 5, pp. 5–471. Eldenäs, P. K., M. Källersjö, and A. A. Anderberg. 1999. Phylogenetic placement and circumscription of tribes Inuleae s. str. and Plucheeae (Asteraceae): Evidence from sequences of chloroplast gene ndhF. Molec. Phylogen. Evol. 13: 50–58. Heywood, V. H., J. B. Harbourne, and B. L. Turner, eds. 1977. The Biology and Chemistry of the Compositae. 2 vols. London, New York, and San Francisco. Hind, D. J. N., H. J. Beentje, P. D. S. Caligari, and S. A. L. Smith, eds. 1996. Proceedings of the International Compositae Conference, Kew, 1994. 2 vols. Kew. Hind, D. J. N., C. Jeffrey, and G. V. Pope, eds. 1995. Advances in Compositae Systematics. Kew. Jansen, R. K. et al. 1991. Phylogeny and character evolution in the Asteraceae based on chloroplast DNA restriction site mapping. Syst. Bot. 16: 98–115. Jansen, R. K. et al. 1992. Chloroplast DNA variation in the Asteraceae: Phyologenetic and evolutionary implications. In: D. E. Soltis et al., eds. 1992. Molecular Systematics of Plants. New York. Pp. 252–294. Jeffrey, C. 1978. Compositae. In: V. H. Heywood, ed. 1978. Flowering Plants of the World. Oxford. Pp. 263–268. Jeffrey, C. 1995. Compositae systematics 1975–1993. Developments and desiderata. In: D. J. N. Hind et al., eds. 1995. Advances in Compositae Systematics. Kew. Pp. 3–22. Kim, K. J. et al. 1992. Phylogenetic implications of rbcL sequence variation in the Asteraceae. Ann. Missouri Bot. Gard. 79: 428–445. Kim, K. J. and R. K. Jansen. 1995. ndhF sequence evolution and the major clades in the sunflower family. Proc. Natl. Acad. Sci. U.S.A. 92: 10379–10383. King, R. M. and H. W. Dawson, eds. 1975. Cassini on Compositae.... 3 vols. New York. Mabry, T. J. and G. Wagenitz, eds. 1990. Research advances in the Compositae. Pl. Syst. Evol., Suppl. 4. Panero, J. L. and V. A. Funk. 2002. Toward a phylogenetic subfamilial classification for the Compositae (Asteraceae). Proc. Biol. Soc. Wash. 115: 909–922. Robinson, H. 1996. Recent studies in the Heliantheae and Eupatorieae. In: D. J. N. Hind et al., eds. 1996. Proceedings of the International Compositae Conference, Kew, 1994. 2 vols. Kew. Vol. 1, pp. 627–653. Small, J. 1919. The Origin and Development of the Compositae. London. [New Phytol. Repr. 11.] Stuessy, T. F., T. Sang, and M. L. DeVore. 1996. Phylogeny and biogeography of subfamily Barnadesioideae with implications for early evolution of the Compositae. In: D. J. N. Hind et al., eds. 1996. Proceedings of the International Compositae Conference, Kew, 1994. 2 vols. Kew. Vol. 1, pp. 463–490. Turner, B. L. 1996+. The Comps of Mexico: A Systematic Account of the Family Asteraceae. 2+ vols. Huntsville, Tex. [Phytologia Mem. 10, 11.] Wagenitz, G. 1976b. Systematics and phylogeny of the Compositae (Asteraceae). Pl. Syst. Evol. 125: 29–46.


Key to Genera of Group 3 Heads radiate; receptacles paleate; pappi none or nearly so

1 Leaves alternate, margins of leaf blades usually 1–3-palmately or -pinnately lobed (ultimate lobes usually linear to filiform), sometimes dentate; phyllaries usually in 3–5+ series, unequal, scarious or margins and/or apices notably scarious   (2)
+ Leaves mostly opposite, and/or sometimes alternate or whorled, margins of leaf blades usually entire, dentate, or lobed, sometimes 1–2-palmatifid or -pinnatifid (ultimate lobes sometimes linear to filiform); phyllaries usually in 3–5+ series and unequal, sometimes in 1–2 series and ± equal to subequal, usually herbaceous to chartaceous, sometimes with margins and/or apices notably scarious   (6)
       
2 (1) Heads in compact to open (± flat-topped), corymbiform or compound-corymbiform arrays; rays 3–5(–12); disc florets (5–)15–30+ (cypselae obcompressed)   113 Achillea, v. 19, p. 492
+ Heads borne singly or in lax, corymbiform arrays; rays 5–30+; disc florets 40–300+ (cypselae mostly not, sometimes weakly, obcompressed)   (3)
       
3 (2) Disc corolla tubes ± cylindric (bases ± saccate or spurred, ± clasping apices of ovaries and/or cypselae); cypsela ribs or nerves (weak) 2 lateral and 1 adaxial   (4)
+ Disc corolla tubes ± compressed or cylindric (bases sometimes proximally dilated, not saccate or spurred); cypsela ribs 9–10, or 0, or 2 lateral (sometimes ± winged) plus 3–10 finer ribs on each face   (5)
       
4 (3) Phyllaries 16–24 in 2–3+ series; rays orange, yellow, or white with yellow bases   114 Cladanthus, v. 19, p. 495
+ Phyllaries 22–45+ in 3–4+ series; rays white   115 Chamaemelum (in part), v. 19, p. 496
       
5 (3) Annuals (biennials); rays usually white, rarely yellow or pink   122 Anthemis, v. 19, p. 537
+ Perennials; rays yellow   128 Cota, v. 19, p. 547
       
6 (1) Annuals; heads obscurely radiate (ray laminae minute; cypselae shed with 2 adjacent, ± fleshy paleae; Arizona)   247 Parthenice, v. 21, p. 23
+ Annuals, biennials, perennials, subshrubs, or shrubs; heads usually conspicuously radiate (laminae showy; cypselae seldom shed with accessory structures)   (7)
       
7 (6) Plants often with tack-glands or pit-glands on stems, leaves, and/or phyllaries; phyllaries (or paleae functioning as phyllaries) usually in 1+ series (each often wholly or partly investing ovary of a subtended floret); paleae often in 1 series between ray and disc florets, often connate in a ring, sometimes each disc floret subtended by a palea; ray laminae often flabellate (lobe lengths often 1/2+ laminae)   (8)
+ Plants without tack-glands or pit-glands; phyllaries in (1–)2–7+ series (seldom each inner phyllary wholly or partly investing ovary of a subtended floret); paleae seldom restricted to 1 series between ray and disc florets, all or nearly all disc florets subtended by paleae; ray laminae seldom flabellate (lobe lengths mostly 0–1/10 laminae)   (22)
       
8 (7) Ray cypselae obcompressed (each mostly or completely enveloped by a phyllary)   (9)
+ Ray cypselae compressed, ± terete, ± 3-angled in cross section, or ± obcompressed (each ± 1/2 enveloped by a phyllary)   (13)
       
9 (8) Annuals, 1–20 cm; disc florets 1(–2)   345 Hemizonella, v. 21, p. 296
+ Annuals or perennials, 2–150 cm; disc florets 3–120+   (10)
       
10 (9) Perennials (rhizomatous); disc corollas white   343 Holozonia (in part), v. 21, p. 294
+ Annuals; disc corollas yellow (sometimes reddish with age)   (11)
       
11 (10) Disc pappi of 10, apically obtuse scales   332 Achyrachaena (in part), v. 21, p. 258
+ Disc pappi 0   (12)
       
12 (11) Calyculi 0 or of 2–5 bractlets; ray florets 5; disc florets 6, function- ally staminate   334 Lagophylla, v. 21, p. 260
+ Calyculi 0; ray florets 3–27; disc florets 4–120+, bisexual   335 Layia (in part), v. 21, p. 262
       
13 (8) Annuals; styles of disc florets hairy proximal to minute branches (receptacles paleate throughout, ray corollas white with abaxial purple lines)   333 Blepharipappus (in part), v. 21, p. 259
+ Annuals, perennials, subshrubs, or shrubs; styles of disc florets glabrous proximal to branches   (14)
       
14 (13) Perennials (± scapiform; disc pappi of subulate, ciliate-plumose scales)   331 Raillardella (in part), v. 21, p. 256
+ Annuals, perennials (leafy-stemmed), subshrubs, or shrubs; disc pappi 0 or of scales, scales seldom both subulate and ciliate-plumose)   (15)
       
15 (14) Annuals or perennials; peduncle bracts without terminal pit-glands, tack-glands, or spines; rays yellow; ray cypselae usually compressed, rarely terete (cross sections usually ± 3-angled, then abaxial sides relatively broad, ± rounded, adaxial sides ± 2-faced, angles between those faces 15–70°; each ray cypsela usually completely or mostly enveloped by a phyllary)   (16)
+ Annuals, subshrubs, or shrubs; peduncle bracts sometimes each with terminal pit-gland, tack-gland, or spine (or apiculus); rays yellow, whitish, or rose; ray cypselae terete to subterete or ± obcompressed (cross sections nearly circular with adaxial sides ± flattened to slightly bulging, or ± 3-angled, then abaxial sides usually ± broadly 2-faced, angles between those faces usually 90+° and adaxial sides ± flattened to slightly bulging; in Centromadia spp., distal leaves spine-tipped, each cypsela ± enveloped by a phyllary, cypselae sometimes compressed)   (17)
       
16 (15) Disc pappi 0   350 Madia (in part), v. 21, p. 303
+ Disc pappi of 5–21 scales (scales sometimes subulate to setiform, bristlelike)   344 Kyhosia (in part), v. 21, p. 295
       
17 (15) Annuals; leaves filiform to narrowly linear, margins often strongly revolute; peduncle bracts usually with tack-glands; ray corolla lobes (at least the lateral) often spreading (lengths often 1/2–5/6 of total laminae)   (18)
+ Annuals, subshrubs, or shrubs; leaves linear or broader, margins seldom strongly revolute; peduncle bracts usually without tack-glands; ray corolla lobes ± parallel (lengths usually 1/10–1/2 of total laminae)   (19)
       
18 (17) Ray cypselae beaked; tack-glands absent   336 Osmadenia (in part), v. 21, p. 269
+ Ray cypselae not beaked; tack-glands present   337 Calycadenia (in part), v. 21, p. 270
       
19 (17) Rays usually white, sometimes yellow, often with abaxial purple lines; cypselae not beaked or each with an inconspicuous, straight beak (beak lengths less than diams.)   342 Hemizonia (in part), v. 21, p. 291
+ Rays yellow (without abaxial purple lines); cypselae each with an adaxial, ascending beak (beak lengths greater than diams.)   (20)
       
20 (19) Peduncle bracts apiculate or each with apical spine   338 Centromadia (in part), v. 21, p. 276
+ Peduncle bracts not apiculate, without apical spines   (21)
       
21 (20) Annuals; peduncle bracts each with apical pit-gland; receptacles paleate throughout   340 Holocarpha, v. 21, p. 287
+ Annuals, subshrubs, or shrubs; peduncle bracts without pit-glands; receptacle paleae usually restricted to bases of outermost disc florets (if in 2–3+ series, subshrubs or shrubs)   339 Deinandra (in part), v. 21, p. 280
       
22 (7) Calyculi of 1–8+ bractlets   (23)
+ Calyculi none   (28)
       
23 (22) Phyllaries connate 1/5–7/8+ their lengths   310 Thelesperma (in part), v. 21, p. 199
+ Phyllaries distinct to bases or nearly so   (24)
       
24 (23) Cypselae (at least inner) ± 4-angled, ± linear-fusiform, often apically attenuate or beaked (none winged)   (25)
+ Cypselae all ± obcompressed   (26)
       
25 (24) Disc florets 10–20 (staminal filaments hairy near anthers); cypselae usually with 1 groove on each face   311 Cosmos, v. 21, p. 203
+ Disc florets (5–)12–150+ (staminal filaments not hairy); cypselae with 0 or 2 grooves on each face   312 Bidens (in part), v. 21, p. 205
       
26 (24) Rays 3–4 (laminae 1–2 mm); inner cypselae ± beaked   313 Heterosperma (in part), v. 21, p. 218
+ Rays usually 1, 2, 3, 5, 8, 13, 21+ (laminae mostly 4–30+ mm); cypselae not beaked   (27)
       
27 (26) Ray florets usually neuter or styliferous and sterile; cypsela wings membranous or corky, entire or irregularly thickened   308 Coreopsis (in part), v. 21, p. 185
+ Ray florets usually pistillate and fertile; cypsela wings ± corky, pectinately toothed   309 Coreocarpus (in part), v. 21, p. 198
       
28 (22) Phyllaries (at least inner) usually falling with cypselae; ray florets pistillate, fertile   (29)
+ Phyllaries persistent (in fruit); ray florets pistillate and fertile, or styliferous and sterile, or neuter   (33)
       
29 (28) Disc florets bisexual, fertile; anther thecae pale   (30)
+ Disc florets usually functionally staminate (bisexual and fertile in Milleriinae, Guizotia); anther thecae dark (blackish to purplish)   (31)
       
30 (29) Phyllaries 10–20 in ± 2 series (outer 4 broadly lanceolate, foliaceous, nota- bly larger than inner)   304 Tetragonotheca (in part), v. 21, p. 178
+ Phyllaries 6–9 in 2 series, subequal or unequal (outer smaller than inner)   306 Galinsoga (in part), v. 21, p. 180
       
31 (29) Rays 6–18 (corollas hairy at bases of tubes); disc florets bisexual, fertile.   259 Guizotia, v. 21, p. 40
+ Rays 3–20+ (corollas seldom hairy at bases of tubes); disc florets functionally staminate   (32)
       
32 (31) Heads borne singly, usually pedunculate; fruits (perigynia) smooth or bullate to tuberculate (1–4 mm)   256 Melampodium (in part), v. 21, p. 34
+ Heads often in clusters of 2–3, mostly sessile; fruits ± prickly (4–8 mm)   257 Acanthospermum (in part), v. 21, p. 36
       
33 (28) Receptacles spheric to high-conic or columnar (mostly 8–20+ mm)   (34)
+ Receptacles mostly flat to convex or conic (mostly 0–5 mm)   (40)
       
34 (33) Phyllaries subequal or unequal (outer longer than inner); ray florets 3–21+, neuter; disc florets 100–200+, bisexual, fertile; stigmatic papillae usually in 2 lines   (35)
+ Phyllaries subequal or unequal (outer usually shorter, rarely longer, than inner); ray florets 3–40+, usually pistillate and fertile, sometimes styliferous and sterile, or neuter; disc florets 4–200+, usually bisexual and fertile, sometimes functionally staminate; stigmatic papillae usually continuous, rarely in 2 lines   (36)
       
35 (34) Involucres (early flowering) hemispheric to rotate, 15–30+ mm diam.; phyllaries 15–30+ in 2–3 series, subequal; cypselae ± 4-angled, not strongly compressed, margins not pectinate or ciliate   261 Rudbeckia (in part), v. 21, p. 44
+ Involucres rotate, 8–12+ mm diam.; phyllaries 14–28+ in 2 series, unequal (outer notably longer than inner); cypselae strongly compressed, abaxial margin of each usually pectinate or ciliate   262 Ratibida (in part), v. 21, p. 60
       
36 (34) Ray florets usually 5–21 (more in "double" cultivars), corollas usually yellow to orange, sometimes purple, red, or whitish (usually persistent, sessile, becoming papery)   266 Zinnia (in part), v. 21, p. 71
+ Ray florets usually (2–)5–35, corollas usually yellow to orange, sometimes white (seldom sessile, laminae usually borne on tubes, never persistent and becoming papery)   (37)
       
37 (36) Disc florets functionally staminate (only ray florets produce cypselae)   (38)
+ Disc florets bisexual, fertile   (39)
       
38 (37) Phyllaries 8–10 in 2 series   268 Lindheimera (in part), v. 21, p. 75
+ Phyllaries 12–45+ in (2–)3–4 series   270 Berlandiera (in part), v. 21, p. 83
       
39 (37) Leaves basal and cauline, alternate; involucres 12–40 mm diam.; rays dark purple to pale pink, white, or yellow   272 Echinacea, v. 21, p. 88
+ Leaves cauline, opposite; involucres 10–15 mm diam.; rays yellow.   291 Pascalia, v. 21, p. 131
       
40 (33) Leaves mostly cauline and alternate (proximal sometimes opposite), or mostly opposite (distal sometimes alternate); ray florets usually neuter or styliferous and sterile   (41)
+ Leaves usually cauline and opposite, sometimes mostly basal and/or mostly alternate; rays florets pistillate and fertile (if neuter, leaves mostly basal or alternate)   (47)
       
41 (40) Disc corollas yellow (bases often dilated, clasping tops of ovaries)   263 Zaluzania, v. 21, p. 63
+ Disc corollas yellow to orange or brown-purple (bases not clasping tops of ovaries)   (42)
       
42 (41) Receptacle paleae each completely investing and falling with a cypsela (each forming a hardened perigynium)   296 Sclerocarpus (in part), v. 21, p. 137
+ Receptacle paleae sometimes conduplicate, ± enfolding cypselae (not forming perigynia)   (43)
       
43 (42) Heads borne singly (peduncles usually distally dilated, fistulose)   297 Tithonia (in part), v. 21, p. 138
+ Heads borne singly or in corymbiform, paniculiform, racemiform, or thyrsiform arrays (peduncles rarely, if ever, notably dilated or fistulose)   (44)
       
44 (43) Cypselae flattened, thin-margined   298 Simsia (in part), v. 21, p. 140
+ Cypselae ± compressed, biconvex, or 3- or 4-angled, often obpyramidal   (45)
       
45 (44) Shrubs (leaves often lobed, lobes usually 3–9, ± linear)   301 Viguiera (in part), v. 21, p. 172
+ Annuals or perennials (leaves not lobed)   (46)
       
46 (45) Annuals; leaf blades lanceolate to linear; involucres 5–6 mm diam.; phyllaries 11–17   299 Helianthus (in part), v. 21, p. 141
+ Annuals or perennials; leaf blades lance-linear, lanceolate, ovate, rhombic, or rhombic-ovate; involucres 6–14 mm diam.; phyllaries 14–25   300 Heliomeris, v. 21, p. 169
       
47 (40) Disc florets functionally staminate   (48)
+ Disc florets bisexual and fertile   (52)
       
48 (47) Anther thecae green, staminal filaments hairy; Arizona   260 Guardiola, v. 21, p. 42
+ Anther thecae dark or pale (not green), staminal filaments not hairy; e United States   (49)
       
49 (48) Ray florets 2–6, corollas pale yellow to whitish; disc florets 12–30+; cypselae (patently inserted on receptacles) 3–6-ribbed or -nerved (finely striate between ribs, apices often minutely beaked)   258 Polymnia (in part), v. 21, p. 39
+ Ray florets 7–13, corollas yellow; disc florets 40–80; cypselae (obliquely inserted on receptacles) 30–40-ribbed or -nerved (not beaked)   (50)
       
50 (49) Cypselae each shed separate from its subtending phyllary   255 Smallanthus, v. 21, p.33
+ Cypselae each enclosed within and shed within a perigynium (formed from an inner, subtending phyllary)   (51)
       
51 (50) Heads borne singly, usually pedunculate; fruits (perigynia) smooth or bullate to tuberculate (1–4 mm)   256 Melampodium (in part), v. 21, p. 34
+ Heads often in clusters of 2–3, mostly sessile; fruits ± prickly (4–8 mm)   257 Acanthospermum (in part), v. 21, p. 36
       
52 (47) Stigmatic papillae in 2 lines   (53)
+ Stigmatic papillae usually continuous, sometimes none (functionally staminate florets), rarely in 2 lines   (55)
       
53 (52) Leaf blades simple; heads borne singly; phyllaries ± connate, ± carinate   359 Eriophyllum (in part), v. 21, p. 353
+ Leaf blades 1–2-pinnately or -pedately lobed; heads in corymbiform to paniculiform arrays; phyllaries distinct, not carinate   (54)
       
54 (53) Leaves cauline, opposite; rays 5–8, pale yellow (fading white)   309 Coreocarpus (in part), v. 21, p. 198
+ Leaves mostly basal, alternate; rays 8, white   351 Hymenopappus (in part), v. 21, p. 309
       
55 (52) Ray florets usually 5–21, corollas usually yellow to orange (usually persistent, sessile, becoming papery)   264 Heliopsis (in part), v. 21, p. 67
+ Ray florets (2–)5–35, corollas usually yellow to orange, sometimes white (seldom sessile, laminae usually borne on tubes, never persistent and becoming papery)   (56)
       
56 (55) Disc florets functionally staminate (only ray florets produce cypselae)   (57)
+ Disc florets bisexual, fertile   (58)
       
57 (56) Phyllaries 8–10 in 2 series   267 Chrysogonum (in part), v. 21, p. 74
+ Phyllaries 12–45+ in (2–)3–4 series   269 Silphium (in part), v. 21, p. 77
       
58 (56) Leaves mostly cauline, mostly opposite   (59)
+ Leaves mostly basal, or basal and cauline, or cauline, mostly alternate   (63)
       
59 (58) Perennials (prostrate; cypselae often rostrate, each with apical boss or neck)   286 Sphagneticola (in part), v. 21, p. 126
+ Annuals or perennials (not prostrate; cypselae not rostrate)   (60)
       
60 (59) Cypselae 3–4-angled (weakly or not at all compressed or obcompressed, epidermes usually thick, corky)   (61)
+ Cypselae (all or at least disc) strongly compressed or obcompressed or flattened (epidermes seldom thick and corky)   (62)
       
61 (60) Rays 20–40, white or whitish (paleae linear-filiform, not conduplicate)   289 Eclipta (in part), v. 21, p. 128
+ Rays 13–21, yellow to orange (paleae lanceolate to ovate, conduplicate)   291 Pascalia (in part), v. 21, p. 131
       
62 (60) Perennials (coarse, 10–150 cm; larger leaves mostly 10–50 cm); involucres 10–50 mm diam.; phyllaries 22–32+ in ± 3 series   280 Helianthella (in part), v. 21, p. 114
+ Annuals or perennials (mostly 10–30+ cm; larger leaves mostly 2–10 cm); involucres 3–6+ mm diam.; phyllaries 8–15+ in 1–3 series   292 Acmella (in part), v. 21, p. 132
       
63 (58) Cypselae prismatic, or nearly so, 3–4-angled   (64)
+ Cypselae compressed to flattened   (67)
       
64 (63) Leaves mostly basal (cauline usually notably smaller than basal)   273 Balsamorhiza, v. 21, p. 93
+ Leaves basal and cauline, or mostly cauline   (65)
       
65 (64) Leaves mostly cauline (blades narrowly oblong to linear, 5–25 mm wide)   274 Scabrethia (in part), v. 21, p. 99
+ Leaves basal and cauline, or mostly cauline (blades mostly 30–120 mm wide)   (66)
       
66 (65) Leaves mostly elliptic, lanceolate, or oblong (basal and cauline, basal usually notably larger than cauline, cauline mostly sessile)   275 Wyethia (in part), v. 21, p. 100
+ Leaves mostly orbiculate, ovate, or rounded-deltate (mostly cauline, mostly petiolate, proximal and distal usually ±similar)   276 Agnorhiza (in part), v. 21, p. 104
       
67 (63) Cypselae winged   277 Verbesina (in part), v. 21, p. 106
+ Cypselae sometimes thin-edged (margins sometimes ciliate or corky-thickened, never truly winged)   (68)
       
68 (67) Perennials (scapiform); leaves all or mostly basal; involucres 20–30+ mm diam   278 Enceliopsis (in part), v. 21, p. 112
+ Perennials (rarely scapiform), subshrubs, or shrubs; leaves usually cauline, sometimes basal and cauline; involucres 4–30 mm diam   (69)
       
69 (68) Perennials (rhizomatous); leaves linear to filiform   279 Phoebanthus (in part), v. 21, p. 113
+ Perennials or shrubs (not rhizomatous); leaves mostly deltate, elliptic, lanceolate, or ovate (and most intermediate shapes, not linear to filiform)   (70)
       
70 (69) Ray florets 8–21, pistillate and fertile   280 Helianthella (in part), v. 21, p. 114
+ Ray florets 8–25(–40), neuter   282 Encelia, v. 21, p. 118

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  • Dahlia sp. (Xiangying Wen)
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    Chinese Plant Names  
  • Acmella oleracea (Taiwan Invasive Species Database)
  • Image/JPEG
  • Espeletia (Trees and shrubs of the Andes of Ecuador)
  • Image/JPEG
  • Loricaria (Trees and shrubs of the Andes of Ecuador)
  • Image/JPEG
  • Pentacalia (Trees and shrubs of the Andes of Ecuador)
  • Image/JPEG
    Flora of Chile  
  • Family PDF (part 1)
  • PDF
  • Family PDF (part 2)
  • PDF
  • Family PDF (part 3)
  • PDF
  • Family PDF (part 4)
  • PDF
    Flora of China  
  • Asteraceae (PDF)
  • PDF
    Interactive Keys by Xiangying Wen  
  • Acmella oleracea (Taiwan Invasive Species Database)
  • Image/JPEG
  • Asteraceae From Wikipedia (Wikipedia, the free encyclopedia)
  • Web Page
  • Image/JPEG (Xiangying Wen)
  • Image/JPEG
  • Asteraceae sp. (Xiangying Wen)
  • Image/JPEG
  • Asteraceae sp. (Xiangying Wen)
  • Image/JPEG
  • Asteraceae sp. (Hong Song)
  • Image/JPEG
  • Chrysanthemum (Xiangying Wen)
  • Image/JPEG
  • Dahlia sp. (Xiangying Wen)
  • Image/JPEG
  • Espeletia (Trees and shrubs of the Andes of Ecuador)
  • Image/JPEG
  • Helanthus salicifolius (Xiangying Wen)
  • Image/JPEG
  • Loricaria (Trees and shrubs of the Andes of Ecuador)
  • Image/JPEG
  • Pentacalia (Trees and shrubs of the Andes of Ecuador)
  • Image/JPEG
  • Rudbeckia hirta (Xiangying Wen)
  • Image/JPEG

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