Alternatively Asteraceae Dum. (nom. altern.)
Including Ambrosieaceae Dum. & Link (reduced, anemophilous Heliantheae), Anthemid(ac)eae Link, Arctotidaceae Bessey, Calendulaceae Link, Cassiniaceae Sch. Bip., Coreopsid(ac)eae Link, Echinopsidaceae Link, Echinopiaceae Link corr. Bullock, Eupatoriaceae Link, Heleniaceae Bessey, Helianthaceae Bessey, Helichrysaceae Link corr. Bullock, Lactucaceae Bessey, Mutisiaceae Burnett, Nucamentaceae Hoffmgg., Partheniaceae Link, Perdici(ac)eae Link, Ritron(ac)eae Hoffmgg. & Link, Senecionaceae(`-idaceae') Bessey, Spurionucaceae Dulac, Vernoniaceae Bessey
Habit and leaf form. Herbs (mostly), or trees (rarely), or `arborescent', or shrubs (rarely), or lianas (rarely); laticiferous, or non-laticiferous and without coloured juice; bearing essential oils, or without essential oils; resinous, or not resinous. `Normal' plants, or switch-plants. Leaves well developed, or much reduced (sometimes). Plants non-succulent, or succulent (a few). Annual, biennial, and perennial; with a basal aggregation of leaves, or with neither basal nor terminal aggregations of leaves. Self supporting (usually), or climbing (rarely); the climbers stem twiners, or scrambling. Hydrophytic (very rarely, e.g. species of Bidens, Cotula), or helophytic, or mesophytic, or xerophytic; the hydrophytes rooted. Leaves of hydrophytes submerged and emergent. Leaves alternate (usually), or opposite (less often), or whorled (rarely); when alternate, spiral; `herbaceous', or leathery, or fleshy, or membranous, or modified into spines; petiolate to sessile; sheathing, or non-sheathing. Leaf sheaths with free margins. Leaves gland-dotted, or not gland-dotted; aromatic, or foetid, or without marked odour; simple, or compound; peltate (occasionally), or not peltate. Lamina dissected, or entire; pinnatifid, or palmately lobed, or runcinate, or spinose. Leaves exstipulate (nearly always), or stipulate (rarely). Lamina margins entire, or crenate, or serrate, or dentate; flat, or revolute, or involute. Leaves without a persistent basal meristem; becoming compound from primordial lobes. Domatia recorded (only from a Vernonia species); represented by pits.
General anatomy. Plants with laticifers (articulated, mainly in the Cichorieae), or without laticifers. The laticifers in leaves, or in stems, or in roots, or in flowers, or in the fruits (in all or different combinations of these).
Leaf anatomy. Hydathodes present (occasionally), or absent.
Lamina with secretory cavities, or without secretory cavities. Secretory cavities containing resin, or containing latex. Minor leaf veins with phloem transfer cells (58 genera), or without phloem transfer cells (Barnadesia and Eupatorium only).
Stem anatomy. Secretory cavities present, or absent; with resin, or with latex. Nodes unilacunar, or tri-lacunar, or multilacunar. Cortical bundles present, or absent. Medullary bundles present, or absent. Internal phloem present, or absent. Secondary thickening absent (?), or developing from a conventional cambial ring, or anomalous; when anomalous, via concentric cambia, or from a single cambial ring. `Included' phloem present (e.g. Chrysanthemoides, Stoebe), or absent. Xylem with libriform fibres; with vessels. Vessel end-walls simple (commonly), or scalariform and simple, or simple and reticulately perforated. Vessels without vestured pits. Wood storied, or partially storied, or not storied; parenchyma typically rather sparse and paratracheal. Sieve-tube plastids S-type. Pith with diaphragms, or without diaphragms.
Reproductive type, pollination. Gynomonoecious (commonly, with hermaphrodite disk florets and female ray florets), or hermaphrodite, or monoecious, or dioecious, or androdioecious (rarely), or gynodioecious (rarely), or polygamomonoecious. Entomophilous (mostly), or anemophilous (in the Anthemideae, which include significant hayfever plants). Pollination mechanism conspicuously specialized (often, and the Cynareae with irritable stamens), or unspecialized.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in `inflorescences'; in heads. The terminal inflorescence unit racemose (but the primary capitula sometimes in cymose secondary heads). Inflorescences nearly always indeterminate heads, but sometimes primary `heads' reduced to single florets are grouped into secondary heads - e.g. Echinops; with involucral bracts; usually more or less pseudanthial. Flowers bracteate (the bracts forming an involucre in one to several series); minute to small; regular, or regular and somewhat irregular, or regular and very irregular (often combining central actinomorphic and marginal `ray' florets); (4-)5 merous; cyclic; tricyclic, or tetracyclic.
Perianth with distinct calyx and corolla, or petaline (calyx sometimes absent - e.g. Ambrosia and relatives); (1-)3-35; 1 whorled, or 2 whorled. Calyx when present, (1-)2-30 (of scales, awns or bristles constituting the `pappus'); represented by bristles (commonly), or not represented by bristles; 1 whorled; persistent, or not persistent; often accrescent (becoming the pappus); open in bud. Corolla 1-3 (ligulate florets), or (4-)5 (disk florets); 1 whorled; gamopetalous; valvate; unequal but not bilabiate (ligulate), or regular, or unequal but not bilabiate and regular, or bilabiate (in Mutisieae).
Androecium 3-5. Androecial members adnate; coherent; 1 - whorled. Stamens 3-5; oppositisepalous (inserted on the corolla tube, alternating with the lobes); filantherous (with short filaments). Anthers cohering (nearly always, forming a tube around the style - with a few exceptions among anemophilous Anthemideae); basifixed; dehiscing via longitudinal slits; tetrasporangiate (usually), or bisporangiate (occasionally); usually appendaged. The anther appendages apical, or apical and basal. Endothecium developing fibrous thickenings. Anther epidermis persistent. Microsporogenesis simultaneous. The initial microspore tetrads tetrahedral, or isobilateral, or decussate. Anther wall initially with one middle layer; of the `dicot' type. Tapetum amoeboid, or glandular (rarely). Pollen grains aperturate, or nonaperturate (perhaps, occasionally?); mostly 3 - aperturate; colporate (commonly), or colpate, or porate, or zoniaperturate; lophate (notably in most Lactucoideae), or not lophate (usually spinulose); 3-celled.
Gynoecium 2; syncarpous; synovarious to synstylovarious; inferior. Ovary 1 locular. Gynoecium median. Epigynous disk usually present (around the base of the style). Styles 2; partially joined; attenuate from the ovary. Stigmas 2; dry type; papillate; Group II type. Placentation basal. Ovules in the single cavity 1; ascending; non-arillate; anatropous; unitegmic; tenuinucellate. Endothelium differentiated. Embryo-sac development Polygonum-type, or Chrysanthemum-type (or unspecified). Polar nuclei fusing prior to fertilization, or not fusing (when apomictic). Antipodal cells formed; 2, or 3 (sometimes becoming multinucleate); proliferating (rarely, with up to 60 cells), or not proliferating. Embryogeny asterad.
Fruit non-fleshy; indehiscent; a cypsella (almost invariably), or a drupe (occasionally). Fruits from adjoining flowers not aggregated into compound fruits. Dispersal unit the fruit. Dispersal commonly by wind via the hairy pappus. Seeds non-endospermic (or endosperm `very thin'). Cotyledons 2 (expanded). Embryo achlorophyllous (17/21); straight (oily).
Seedling. Germination phanerocotylar.
Physiology, biochemistry. Cyanogenic (rarely), or not cyanogenic. Cynogenic constituents phenylalanine-derived, or of Hegnauer's `Group C'. Polyacetylenes recorded. Alkaloids present, or absent. Iridoids absent. Proanthocyanidins absent (with the exception of Cosmos bipinnatus, with a trace of cyanidin). Flavonols present (mostly), or absent; kaempferol, or quercetin, or kaempferol and quercetin. Ellagic acid practically always absent (absent from 40 species and 28 genera, with a positive record only for Tagetes patula). Arbutin present, or absent. Ursolic acid present. Saponins/sapogenins present, or absent. Aluminium accumulation not found (but many accumulate selenium). Inulin recorded (very widespread). C3, or C4, or CAM, or C3-C4 intermediate. C3 recorded in Acanthospermum, Achillea, Ambrosia, Arctium, Artemisia, Aster, Baccharis, Bahia, Bebbia, Bidens Blainvillea, Centaurea, Ceruana, Chrysactinea, Chrysanthemum, Cirsium, Clappia, Coreocarpus, Coreopsis, Cosmos, Dicoma, Dyssodia, Echinops, Encelia, Erodiophyllum, Eupatorium, Flaveria, Franseria, Galinsoga, Goldmanella, Grangea, Grangeopsis, Grindelia, Guizotia, Gymnolaena, Haplopappus, Helianthus, Heterospermum, Hidalgoa, Hofmeisteria, Hymenoclea, Isocoma, Iva, Lactuca, Lagenophora, Leucactinia, Liatris , Matricaria, Myriactis, Nicolletia, Oligochaeta, Parthenium, Peucephyllum, Plagiocheilus, Pluchia, Pulicaria, Rhynchospermum, Schizotrichia, Solenogyne, Solidago, Sonchus, Stephanomeria, Strotheria, Tagetes, Taraxacum, Thelesperma, Tragopogon, Trichoptilium, Trichospira, Urbinella, Varilla, Vernonia, Xanthium, Zinna. C4 recorded in Chrysanthellum, Eryngiophyllum, Flaveria, Glossocardia, Glossogyne, Isostigma, Pectis. CAM recorded in Aeonium, Aster, Kleinia, Notonia, Senecio. C3-C4 intermediacy in Flaveria (10 species) and Parthenium hysterophorus. Anatomy C4 type (Chrysanthellum, Flaveria, Parthenium, Pectis), or non-C4 type (numerous genera).
Geography, cytology. Frigid zone, temperate, sub-tropical, and tropical. Cosmopolitan. X = 2-19(+). Supposed basic chromosome number of family 9.
Taxonomy. Subclass Dicotyledonae; Tenuinucelli. Dahlgren's Superorder Asteriflorae; Asterales. Cronquist's Subclass Asteridae; Asterales. Takhtajan's Subclass Asteridae; Asteranae; Asterales. Species 13000. Genera 1500; Abrotanella, Acantholepis, Achillea, Achyrocline, Achyropappus, Acomis, Acourtia, Actites, Adenopappus, Ageratum, Agoseris, Alciope, Amauria, Amblyopappus, Ambrosia, Anaphalis, Anexeton, Anisocoma, Antennaria, Anthemis, Apostates, Arctium, Arctotis, Arnica, Artemisia, Aster, Athanasia, Baccharis, Baileya, Balduina, Bebbia, Bedfordia, Bellis, Bidens, Bigelowia, Blepharispermum, Blumea, Boltonia, Brachycome, Brachylaena, Brickellia, Buphthalmum, Burkartia, Cacalia, Calea, Calendula, Calotis, Carduus, Carlina, Carthamus, Cassinia, Celmisia, Centaurea, Chardinia, Chondrilla, Chrysanthemum, Cichorium, Cirsium, Cnicus, Colobanthera, Conyza, Coreopsis, Cosmos, Cotula, Crepis, Cynara, Dahlia, Dasyphyllum, Delilia, Dendroseris, Dicoma, Dimorphotheca, Doronicum, Dyssodia, Echinacea, Echinops, Ekmania, Emilia, Erechtites, Erigeron, Erythrocephalum, Eupatorium, Euryops, Felicia, Filago, Fitchia, Flaveria, Freya, Gaillardia, Galinsoga, Gazania, Gerbera, Glossocardia, Gnaphalium, Gonospermum, Grindelia, Gundelia, Gymnodiscus, Gynura, Happlopappus, Helenium, Helianthus, Helichrysum, Heteropappus, Hieracium, Hippia, Homogyne, Hulsea, Hyaloseris, Hymenopappus, Hymenothrix, Hyoseris, Hypochaeris, Inula, Isocarpha, Iva, Ixeris, Ixodia, Jasonia, Jungia, Kleinia, Krigia, Lachanodes, Lachnospermum, Lactuca, Lagenophora, Lapsana, Lembertia, Leontodon, Leptocarpha, Lescaillea, Leucanthemum, Leuzea, Liabum, Ligularia, Litothamnus, Lopholaena, Lycoseris, Macrachaenium, Mairia, Matricaria, Micropsis, Microseris, Mikania, Millotia, Moonia, Moquinia, Mutisia, Neurolaena, Nestlera, Notobasis, Olearia, Oliganthes, Ondetia, Onoseris, Osteospermum, Othonna, Pachylaena, Parasenecio, Parthenium, Pectis, Petasites, Peucephyllum, Phania, Picris, Pilosella, Piptothrix, Platycarpha, Pluchea, Printzia, Prolobus, Psilocarphus, Pterocaulon, Pulicaria, Pyrrhopappus, Quinetia, Raoulia, Rennera, Rigiopappus, Robinsonia, Rudbeckia, Sachsia, Santolina, Sanvitalia, Saussurea, Scolymus, Scorzonera, Senecio, Serratula, Sigesbeckia, Silybum, Solidago, Soliva, Sonchus, Stenops, Stevia, Stilpnogyne, Stifftia, Stokesia, Tagetes, Tanacetum, Taraxacum, Tephroseris, Tetradymia, Thespidium, Thespis, Tithonia, Tolpis, Tragopogon, Trichocoryne, Trichogyne, Tussilago, Unxia, Ursinia, Verbesina, Vernonia, Viguiera, Werneria, Wyethia, Xanthium, Xanthopappus, Youngia, Zinnia, etc.
Heywood, Harborne and Turner 1977.
Economic uses, etc. Sources of foodstuffs include Lactuca (lettuce), Cynara (globe artichoke), Cichorium (chicory and endive), Tragopogon (salsify). Insecticides from Pyrethrum, safflower dye from Carthamus. At least 200 genera are widely planted as ornamentals; and some are notorious hayfever plants (`ragweed' (Ambrosia), etc.).
Illustrations. compo495.gif compo496.gif compo498.gif compo499.gif compo501.gif compo502.gif compo545.gif
Additional, to be intercalated. Mikania twining anticlockwise.
