Asteraceae Bercht. & J.Presl

Timothy Utteridge & Gemma Bramley (2020). The Kew Tropical Plant Families Identification Handbook, Second Edition. Kew Publishing Royal Botanic Gardens, Kew

Note

Herbs and subshrubs, rarely trees. Leaves opposite or alternate. Flowers small, aggregated into a head; calyx reduced; corolla of 5 united petals; stamens 5, anthers united into a tube; ovary inferior. Fruit indehiscent, 1-seeded.

Recognition

Characters of similar families: Gesneriaceae: leaves opposite, flower zygomorphic, showy, many-seeded capsule or drupe. Lamiaceae: leaves opposite, flower zygomorphic, showy, fruit of up to 4 nutlets, or drupe with 1–5 stones. Acanthaceae: leaves opposite, cystoliths present, flower zygomorphic, showy, fruit a bilocular capsule. Urticaceae: leaves 3-veined, discolorous, cystoliths present, flowers minute, stamens free, inflexed in bud, stigma 1. Amaranthaceae: stems angular, nodes swollen, inflorescence of spikes or heads, flowers associated with dry papery bracts.

Morphology General Habit

Herbs, subshrubs, shrubs or less often trees, sometimes lianous, rarely epiphytic or aquatic. Leaves opposite or alternate, rarely whorled; tissues with schizogenous resin-ducts or articulated laticifers

Morphology Reproductive morphology Flowers

Flowers (florets) small, of one or more kinds, aggregated into a head (capitulum) surrounded by a protective sheath (involucre) of bracts (phyllaries), sessile or subsessile on a receptacle, with or without subtending scales (paleae) or bristles; calyx (pappus) represented by awns, scales or earshaped structure or completely absent, never green and herbaceous; corolla gamopetalous, usually of 5 united petals, often actinomorphic, sometimes zygomorphic and bilabiate (3+2), pseudobilabiate (4+1), rayed (with a limb with 1–4 apical teeth), or ligulate with 5 apical teeth; stamens usually 5, inserted on the corolla, anthers usually united into a tube; ovary inferior, ovule 1, styles elongating within anther-tube, dividing into 2 stylearms with stigmatic surfaces on inner sides

Morphology Reproductive morphology Fruits

Fruit indehiscent, 1-seeded, usually dry (achene or cypsela), rarely fleshy (drupe).

Distribution

A family, conservatively, of three subfamilies (molecular studies have recognised six), divided into 13 tribes (over 40 might be recognised after molecular studies), c. 1,600 genera, and varying estimates of up to 25,000 species. The size of the Compositae in some floras approaches 10–15% of the total species.

Ecology

The family is cosmopolitan especially in temperate zones, subtropics and tropics, but is rare in true tropical rain forests.

Description Author

Nicholas Hind

Milliken, W., Klitgard, B. and Baracat, A. (2009 onwards), Neotropikey - Interactive key and information resources for flowering plants of the Neotropics. http://creativecommons.org/licenses/by/3.0

Morphology General Habit

Annual or perennial herbs, subshrubs or shrubs, climbers, lianes or ramblers, small or, rarely, large trees, epiphytes, very rarely true aquatics, glabrous or with simple, glandular, malpighiaceous or stellate hairs, often glabrescent; plants usually monoecious, rarely dioecious, odourless or rarely with distinctive odour

Morphology Roots

Rootstocks fibrous or fleshy, sometimes with distinct woody perennating rootstocks (xylopodia)

Morphology Stem

Stems usually unarmed, rarely spiny

Morphology Leaves

Leaves alternate or opposite, sometimes rosulate, rarely whorled, estipulate, lamina simple, rarely compound, variously shaped, pinnately or palmately veined, usually herbaceous, sometimes fleshy, coriaceous, or chartaceous, sessile or petiolate, sometimes with an expanded, sheathing or auriculate base but never stipulate, margins lobed or variously toothed, rarely spiny and rarely ending in a tendril, and rarely reduced to scales and falling rapidly

Morphology Reproductive morphology Inflorescences

Inflorescence of capitula usually cymosely arranged within flowering structure but also in corymbose panicles, or rarely spicate, sometimes scapiform, rarely secondarily aggregated into spikes or glomerules, or very rarely arranged in compound structures or synflorescences (syncalathia) possessing a secondary receptacle, rarely also with a secondary involucre, sometimes each individual capitulum within compound structure reduced to single-flowered condition

Morphology Reproductive morphology Inflorescences Capitulum

Capitula homogamous and all florets hermaphrodite or more rarely all male (staminate) or all female (pistillate), very rarely unisexual capitula borne on same plant or on different plants, capitula discoid (with all florets tubular and actinomorphic), ligulate (with all florets ligulate), or bilabiate (with all florets bilabiate), and all florets hermaphrodite, all male, or all female, or capitula heterogamous and radiate with outer marginal florets female (pistillate), or sterile or neuter, and radiate in one or more whorls, and inner disc florets usually hermaphrodite with tubular corollas, or heterogamous and disciform (possessing at least 2 types of eradiate florets, usually with filiform outer florets and central tubular hermaphrodite florets), or heterogamous and radiant (possessing inner hermaphrodite florets and outer enlarged, usually sterile or neuter marginal florets) Primary inflorescence a capitulum, usually chasmogamous, very rarely cleistogamous, usually of many small individual flowers (florets), sometimes reduced to 1, surrounded by an involucre of protective bracts (phyllaries) in one or more series, cylindrical, to globular or urceolate; phyllaries imbricate, subimbricate or distant, usually gradate or sometimes subequal, rarely outer longer than inner, usually homomorphic, very rarely heteromorphic, often chartaceous or herbaceous, sometimes with characteristic apical appendages, rarely with an outer series of subinvolucral bracts forming a calyculus; receptacle solid or hollow, concave, flat or convex, rarely conical or almost cylindrical, surface plane, variously ornamented and areolate, alveolate or fimbriate around achene attachment points, commonly naked but sometimes with chaffy bracts (paleae), scales, bristles or hairs between florets

Morphology Reproductive morphology Flowers Florets

Florets few, very rarely 1, to many, arranged racemosely or indeterminately within capitula, outer opening first; corollas variously coloured, actinomorphic and typically in disk florets in radiate, or throughout discoid, capitula, or with zygomorphic corollas and bilabiate (with a 3-toothed outer lip and 2- lobed inner lip), pseudobilabiate (with a 4-toothed outer lip and a 1- lobed inner lip), rayed (lacking adaxial lobes but with a limb with 1 to 4 apical teeth), or ligulate (with a flat, strap-shaped limb with 5 apical teeth), glabrous or variously pubescent (eglandular or glandular), corolla lobes short or long, glabrous or variously pubescent, often with thickened apical margin; anthers typically connate (exceedingly rarely anthers free), usually 5 (rarely 4) forming a tube around the style, and dehiscing introrsely, dorsifixed or basifixed, conspicuously exserted from, or included within corolla throat, apical anther appendages (diagnostic in many genera in Eupatorieae) acuminate, apiculate, acute, obtuse, usually persistent, basal anther appendages calcarate and caudate, rarely ecalcarate, tails long or short, entire or variously laciniate, rarely branched or pilose; filaments inserted basally inside corolla tube, higher up in tube or just beneath sinuses of corolla -lobes, usually glabrous, rarely papillose or even hairy, very rarely filaments fused together, filaments often with a conspicuous (and diagnostic) anther or filament collar just below insertion point on anther; styles often well exserted from corolla throat and anther cylinder, usually divided into 2 style arms (rarely connate) each with stigmatic surface on inner surface, style hairy, hairs acute or obtuse to rounded, papillose or glabrous, sometimes with distinctive (and diagnostic) basal node, with or without a nectary, glabrous or pubescent; style arms sometimes with characteristic sterile apical appendages, stigmatic papillae often conspicuous and arranged along style arm margins or inner surfaces or inconspicuous and either marginal or all over inner surfaces

Morphology Reproductive morphology Fruits

Fruit single-seeded, indehiscent, lacking endosperm, developing from an inferior ovary (a cypsela, although commonly termed an achene), obovoid or oblong, fusiform or distinctly beaked, terete, angular, rounded, variously compressed or curved, ribbed, angled, variously ornamented .

Diagnostic

Notable genera and distinguishing features: Within the Neotropics there are very many notable genera, and certainly too many to separate out. In each ecostystem, within each of the countries in the area, there may well be dominant, or abundant, or otherwise noteworthy Compositae. With the exception of the rainforest, and extensive aquatic habitats, the family is present in most of the ecosystems found in the area. It is especially important to make sure that fertile material is collected that shows all floret types open and ideally with mature achenes - although achene maturation will usually take place whilst material is being dried in the press. In many genera pappus length varies considerably between flowering and fruiting material, as does achene shape and size (especially in those taxa developing beaked achenes), and often receptacular paleae grow (and can change colour) considerably in fruiting capitula.   Key to tribes of the Compositae (Asteraceae) in the Neotropics 1. Corolla inside and outside and all other floral parts bearing simple, uniseriate, eglandular, 3-celled hairs; plants often with axillary spines or thorns — 1. Barnadesieae1. Corollas and other floral parts lacking such hairs but often with hairs of other kinds, or glabrous; stems lacking spines or thorns, or if stems apparently spiny these formed from branch and branchlet apices — 2 2.  Corollas all ligulate (i.e. all strap-shaped, equally 5-toothed at apex) — 32.  Corollas not ligulate, or if strap-shaped then limb with 4 or less apical teeth, or teeth unequal — 4 3.  Plants lacking latex; style arms lacking collector hairs — 2. Mutisieae p.p. (Hyaloseris)3.  Plants with latex; style arms subulate, pubescent outside and to below bifurcation on style shaft — 6. Lactuceae 4.  Phyllaries uniseriate, usually cohering by overlapping margins, or partly or wholly connate, calyculate or ecalyculate; pappus present — 54.  Phyllaries imbricate in 2 or more series, free or connate, if uniseriate then not cohering or pappus absent or capitula unisexual — 6 5.  Plants with oil glands on leaves and phyllaries; achenes black when mature — 12. Heliantheae p.p.5.  Plants lacking oil glands; achenes never black when mature — 7. Senecioneae p.p. 6.  Style arms bifurcate or short-bifid, pilose outside; upper part of style shaft pilose — 76.  Style arms bifurcate or bilobed, rarely connate, not pilose outside; upper part of style glabrous or sometimes with a ring of hairs just beneath style arm division — 9 7.  Florets isomorphic, all hermaphrodite; corolla tubular, usually long lobed — 4. Vernonieae7.  Florets dimorphic, outer florets female with filiform corollas or with rays, disc florets tubular, hermaphrodite or male; corolla lobes short — 8 8.  Outer florets filiform; leaves alternate; plants never with latex — 11. Inuleae p.p.8.  Outer florets rayed; leaves opposite (rarely rosettiform); plants with or without latex — 5. Liabeae 9.  Capitula with all or only outer florets bilabiate (i.e. corollas with 3-toothed outer lips and 2-lobed inner lips) — 2. Mutisieae p.p.9.  Capitula lacking bilabiate florets, corollas all tubular or outer florets distinctly rayed, ray limb not bilabiate — 10 10.  Style with ring of hairs just beneath style arms — 3. Cardueae10.  Style arms lacking ring of hairs and glabrous or variously papillate or pubescent — 11 11.  Anther bases not sagitate, base of thecae obtuse — 1211.  Anther bases conspicuously sagitate, thecae long-acute or acuminate — 13 12.  Capitula with marginal filiform female florets; style arms truncate with a corona of hairs — Inuleae p.p.12.  Capitula with all florets tubular; style arms obtuse and lacking collector hairs — 2. Mutisieae p.p. 13.  Style arms long, linear or apically clavate, covered in short papillae beginning conspicuously above base of style arms (florets isomorphic, all hermaphrodite, tubular; corollas never yellow) — 13. Eupatorieae13.  Style arms short, in upper part covered in collector hairs, rarely without collector hairs, or long [account for this if necessary] (florets isomorphic or dimorphic, hermaphrodite corollas usually yellow) — 14 14.  Style arms truncate or obtuse — 1514.  Style arms subulate to triangular — 17 15.  Pappus of capillary setae; involucre calyculate — 7. Senecioneae p.p. (Culcitium)15.  Pappus absent or a hyalinecorona; involucre ecalyculate — 16 16.  Phyllaries with scarious, usually brown margins; achenes relatively small, monomorphic or sometimes dimorphic, pappus a lacerate crown or auricle, or absent; leaves often pinnatipartite — 10. Anthemideae16.  Phyllaries green and herbaceous; achenes relatively large, polymorphic, epappose; leaves entire or lobed — 8. Calenduleae (Calendula) 17.  Achene body never black, very frequently setuliferous, rarely glabrous; pappus usually of capillary barbellate setae, or absent, rarely of squamellae and then falling rapidly; leaves usually alternate, but never scabrid pubescent; receptacle usually epaleaceous — 9. Astereae17.  Achene body black, usually glabrous or sometimes setuliferous; pappus of scales, squamellae, aristae or awns, or absent, but never of capillary setae, or if setae present these plumose; leaves frequently opposite and scabrid pubescent; receptacle frequently paleaceous — 12. Heliantheae Distinguishing characters (always present): The combined presence of diminutive flowers (termed florets) massed into a capitulum surrounded by protective involucral bracts (termed phyllaries) in one or more series. Gamopetalous corolla. A style with two apical style arms (usually, but not always, divided). 5 anthers united into a cylinder around the style and dehiscing antrorsely. Pappus of capillary setae or of scales (although sometimes absent). Fruit an achene (or more correctly a cypsela). Key differences from similar families: Close examination will place all members of the Compositae within the family without any great difficulty. However, superficial examination may well place some taxa, albeit very rarely, into other families. Both vegetative and fertile material of Ichthyothere is sometimes misplaced in the Commelinaceae. Material from other families is often placed in the Compositae, most notably members of the Acanthaceae, Amaranthaceae, Labiatae and sometimes Rubiaceae. All of these families are instantly thrown out because they have: Free stamens. Capitate stigmas. Typically distinct calyces. No pappus -like structure. Very distinctive fruiting structures.   Allied families, such as the Calyceraceae and Goodeniaceae, and other families historically placed close to the Compositae, such as the Dipsacaceae and Valerianaceae, are similarly easy to distinguish upon close examination.

Distribution

In each of the main countries in the Flora area there are very high percentages of native taxa, and significant percentages of endemics. Many weedy taxa, from both New World and Old World, exist within the Flora area and there are many Neotropical taxa naturalized within others. Found throughout the Neotropics, although species numbers are restricted in rainforest and extensive aquatic habitats. The family is particularly common in montane habitats, disturbed areas and in semi-arid regions, and is common (as weeds) in most cultivated regions.

Note

MINIMAL GLOSSARY OF TERMS USED WITHIN THE COMPOSITAE NB. Because of the higher orders of arrangement found in the flowering structures of the family many terms have modified definitions. achene: a one-seeded fruit. antherappendage: usually refers to the apical appendages; basalanther -appendages are often highly characteristic at generic level. anther collar: a region of cells, often denoted by swelling, at apex of filament below anther, sometimes called a filament collar. awn: a stiff bristle-like pappus. barbellate: usually referring to pappus -setae where the branches of the seta are markedly shorter than the diameter of the seta. beak: referring to achene (Chaptalia, etc.) where the apex of the achene is elongated below the pappus; also rostrate. bilabiate: two-lipped. callus: zone at base of pappus at its point of attachment to the achene. capitulescence: see inflorescence. capitulum [pl. capitula]: the organ where the florets are surrounded by primary phyllaries (involucral bracts) - the 'inflorescence' of the Compositae; also calathia. carpopodium: basal callus of achene, representing the abscission zone. discfloret: actinomorphic usually hermaphrodite, functionally male or sterile florets in the middle of the capitulum. disciform: a capitulum bearing outer filiform florets and inner tubular disc florets. discoid: a capitulum bearing identical florets all with tubular corollas. floret: the diminutive flower in the Compositae capitulum. flowering stem: the main stem of the inflorescence. glomerule: a small compact cluster usually representing a secondary aggregation of capitula, also a synflorescence. glomerulescence: the whole flowering structure made up of glomerules. heterogamous: a capitulum bearing two different types of florets, usually ray and disc florets. homogamous: a capitulum in which all florets are identical and usually hermaphrodite, but also all male florets, or all female in dioecious taxa. inflorescence: the whole flowering structure, including all capitula on the flowering stem. inflorescence branch: a branch, off of the peduncle or flowering stem, bearing one or more capitula. infructescence: a cluster of fruits derived from an inflorescence. involucre: the part of the capitulum made up of the phyllaries. ligulate: bearing a strap-shaped corollalimb with five teeth at its apex, or referring to a capitulum of ligulate florets. ligule: a corollalimb with five teeth at its apex. limb: the extended portion of a corolla, e.g. ray limb. palea (pl. paleae): sub-floral bracts found on the receptacle either as hairs or scales. pappus: considered to be the modified remnant of the calyx, usually capillary but sometimes scale-like or coroniform. pedicel: the ultimate branch of an inflorescence bearing a capitulum. peduncle: the common stalk of the inflorescence bearing several capitula (which may be borne on inflorescence branches). phyllary: an involucral bract. plumose: feather-like, usually referring to a pappus seta bearing lateral branches whose length are more than the diameter of the main seta. radiant: a capitulum with inner hermaphroditedisc florets and outer enlarged steriledisc florets. radiate: a capitulum with outer ray florets and inner disc florets. ray: the predominant limb of the outer florets in a heterogamous capitulum. ray floret: the outermost florets in a heterogamous capitulum bearing a ray limb. receptacle: the common area of attachment of the florets in the capitulum. scape: a leafless inflorescencestem bearing a single capitulum or synflorescence. seta (pl. setae): a bristle or stiff hair, usually a unit of a pappus. setuliferous: short stiff bristly pubescence, usually pertaining to the pubescence of an achene. squamellum (pl. squamellae): a broadened bristle or scale-like unit of the pappus. stipe: a stalk. style arm: the upper divisions of the style. subplumose: almost feather-like, usually referring to a pappus seta bearing lateral branches whose length is slightly less than the diameter of the seta. subradiate: a heterogamous capitulum with the outer florets bearing rays not exceeding the phyllaries. synflorescence: a conglomeration of capitula enclosed in secondary or tertiary involucres borne on a secondary receptacle; also syncalathium. vallecular canal: usually a resin canal opposite a longitudinal sulcus. xylopodium: woody subterranean rootstock, sometimes slightly fleshy. Notes on delimitation: This is one of the 'natural' families, and as such there is no problem in delimiting the family, since all members can be properly attributed to it with careful examination. The number of subfamilies in the Compositae has risen to over a dozen (and likely to rise still further), with the somewhat impractical expansion of the number of tribes to 30. From a purely practical point of view, in terms of teaching and fieldwork, there is little wrong in recognizing the tribes as proposed by Bentham (1873), but recognizing a separate Barnadesieae and Liabeae, and combining the Helenieae within a broader circumscription of the Heliantheae. Within the Neotropics I currently recognize 13 tribes as possessing native or naturalized species; only the tribe Arctotideae is absent although some species may well be cultivated. A key to the tribes found in the Neotropics is provided below, together with diagnostic/conspectus-like descriptions of each of the tribes above. Number of genera: c. 1600 total for family globally; total as yet unknown in the Neotropics.

Gemma Bramley, Anna Trias-Blasi & Richard Wilford (2023). The Kew Temperate Plant Families Identification Handbook. Kew Publishing Royal Botanic Gardens, Kew

Recognition

Characters of similar families: Caprifoliaceae (Dipsacoideae): annual or perennial herbs (rarely shrubs), leaves opposite or verticillate, inflorescences of dense cymose capitula surrounded by bracts, florets all hermaphrodite, corollas usually zygomorphic, 4- or 5-lobed, stamens 5 (free), stigma simple or 2-lobed, fruit dry and indehiscent, enclosed in epicalyx, calyx persistent. Eriocaulaceae: annual or perennial herbs; leaves all basal, alternate, spiralled or distichous, inflorescences of capitula surrounded by bracts, florets bracteate, actinomorphic or zygomorphic, sepals 2 or 3, petals 2 or 3, stamens 2–6, ovary 2- or 3-locular, styles 1–3, fruit dry and dehiscent capsule.

Morphology General Habit

Terrestrial annual, biennial or perennial herbs, suffrutices, subshrubs, or shrubs (rarely trees) Acaulous, or stems herbaceous or woody, simple or branched, leafy or leafless

Morphology Leaves Stipules

Stipules absent

Morphology Leaves

Leaves alternate, opposite or rosulate

Morphology Reproductive morphology Inflorescences

Inflorescences terminal or axillary, scapose, scapiform or variously branched

Morphology Reproductive morphology Inflorescences Capitulum

Capitula homogamous and discoid or ligulate, or heterogamous and disciform or radiate, rarely radiant; involucre urceolate, campanulate, turbinate or cylindrical; phyllaries 1–many-seriate, distant or imbricate and gradate; receptacle concave, flat, convex or conical, paleaceous or epaleaceous, glabrous or pubescent

Morphology Reproductive morphology Flowers Florets

Florets small, hermaphrodite, or functionally male, female or sterile; corollas actinomorphic, filiform or tubular and (3–4) 5-lobed, or zygomorphic and bilabiate, ligulate (with 5 apical teeth), or pseudoligulate, rarely absent

Morphology Reproductive morphology Flowers Androecium Stamens

Stamens 5, epipetalous; anthers usually united into cylinder, often with apical and basal appendages

Morphology Reproductive morphology Flowers Gynoecium Style

Style with or without basal node, glabrous or variously pubescent, style arms 2, often well-exserted from anther cylinder

Morphology Reproductive morphology Flowers Gynoecium Ovary

Ovary inferior, unilocular; ovary solitary, basal, anatropous

Morphology Reproductive morphology Fruits

Fruit an achene (=cypsela), with or without an apical pappus of setae or scales, usually uni- or bi-seriate, setae capillary or flattened, smooth, finely to coarsely barbellate or plumose, or reduced to a corona or auricule.

Distribution

A family of ca. 1,650 genera and ca. 25,000 species. A few genera contain apomictic microspecies that can be difficult to identify (e.g. Taraxacum and Hieracium), and could increase species numbers considerably. A global family, widespread in most temperate ecosystems, rare in aquatic environments and Antarctica. Five subfamilies, classically 14 tribes but potentially 40+ following recent phylogenetic proposals, with some tribal concepts difficult to promote.

Note

Inflorescence a capitulum of an involucre of phyllaries enclosing florets; florets hermaphrodite or unisexual. Corollas actinomorphic or zygomorphic, surrounding 5 connate anthers, enclosing a style with 2 style arms. Fertile florets producing an achene usually with a pappus of scales or hairs.

Description Author

DJ Nicholas Hind

Compositae, C.d. Adams. Flora of West Tropical Africa 2. 1963

Morphology General Habit

Herbs, shrubs or rarely small trees or climbers

Morphology Leaves

Leaves alternate or opposite, simple or variously divided; stipules absent

Morphology Reproductive morphology Flowers

Florets of one or two kinds in each capitulum, hermaphrodite, unisexual or neuter, rarely dioecious, the outer ones often ligulate (ray-florets), the inner ones tubular (disk-florets), or all tubular, or all ligulate Flowers (florets) crowded into heads (capitula) surrounded by an involucre of one or more series of free or connate bracts; sometimes the heads compound with the capitula few- or single-flowered; receptacle paleate, setose, pitted or naked, usually convex, sometimes elongated or concave

Morphology Reproductive morphology Flowers Calyx

Calyx epigynous, reduced to a pappus of persistent or caducous hairs, bristles or scales, or absent

Morphology Reproductive morphology Flowers Corolla

Corolla sympetalous, 4-5-fid (actinomorphic disk-florets), filiform, ligulate or rarely bilabiate (zygomorphic ray-florets)

Morphology Reproductive morphology Flowers Androecium

Stamens 5, rarely 4, epipetalous; filaments free; anthers connate into a tube, rarely free, 2-locular, opening lengthwise, often appendaged at the apex and tailed at the base

Morphology Reproductive morphology Flowers Gynoecium

Ovule erect from the base Ovary inferior, 1-locular, 1-ovuled; style of the hermaphrodite or female florets mostly 2-fid, the style-arms smooth, papillose or hairy, tapered, rounded, deltoid or truncate, with or without a terminal appendage

Morphology Reproductive morphology Fruits

Fruit (achene) sessile, sometimes beaked

Morphology Reproductive morphology Seeds

Seed without endosperm; embryo straight with plano-convex cotyledons

Compositae, G. V. Pope. Flora Zambesiaca 6:1. 1992

Morphology General Habit

Annual, biennial or perennial herbs (often suffrutescent in the Flora Zambesiaca area with annual leafy stems or scapes from woody rootstocks and/or root tubers), or subshrubs, shrubs, or occasionally scramblers or lianes, sometimes trees, rarely aquatic or epiphytic, sometimes succulent, sometimes spinescent; tissues with schizogenous resin-ducts or articulated lacticifers

Morphology Leaves

Leaves cauline and alternate or opposite, sometimes whorled, or radical and rosulate, exstipulate or sometimes with stipuliform appendages, sessile or petiolate, usually simple, entire, toothed, lobed or variously dissected

Morphology Reproductive morphology Inflorescences

Inflorescence a capitulum with individual flowers ± sessile and aggregated on a common receptacle and surrounded by an involucre of 1-many series of bracts (phyllaries) Capitula heterogamous disciform - florets of 2(3) sexual states, the inner florets hermaphrodite or functionally male and the outer ones filiform and female; all corollas regular Capitula heterogamous radiant - inner florets hermaphrodite or functionally male, marginal florets larger and neuter; all corollas regular Capitula homogamous ligulate - all florets hermaphrodite; all corollas ligulate Capitula heterogamous radiate - central florets hermaphrodite or female or functionally male, outer florets female or neuter, occasionally hermaphrodite; central floret corollas regular, outer or marginal floret corollas radiate, or occasionally bilabiate with a strap-shaped outer lip Capitula heterogamous bilabiate - inner florets functionally male, outer florets female; corollas bilabiate, in the Flora Zambesiaca area the inner corollas are all equally 2-lipped, while the outer corollas are of 2 kinds, i) 2–3 series of submarginal corollas equally 2-lipped, ii) a marginal series in which the corolla outer lip is strap-shaped (apparently radiate) and the inner lip smaller and 2-lobed (eg. Gerbera, Tab. 9). Occasionally all florets male or all female (plants monoecious or dioecious), or the disk-florets functionally female and the ray-florets functionally male Capitula solitary and terminal on scapes or leafy stems, or few to very numerous in lax or ± clustered cymose, often corymbiform synflorescences, occasionally scorpioidly cymose (a reduced cymose arrangement in which the subtending bracts are alternate), or spicate, racemose or paniculate, or aggregated into secondary capitula (glomerules) Common receptacle with scales (paleae) or setae subtending the florets, or epaleate and the surface smooth areolate or shallowly to deeply honeycombed (alveolate); alveolae often fimbriate or setose Phyllaries in 2-many series, free and imbricate or ± connate, or sometimes 1-seriate and united or with cohering overlapping margins, persistent or rarely caducous, occasionally accrescent, sometimes apically appendaged

Morphology Reproductive morphology Flowers Calyx

Calyx absent, represented by the pappus borne apically on the ovary; pappus consisting of persistent or caducous, 1 -many-seriate hairs bristles awns or scales, or pappus elements ± fused to form an annular or ± cup-shaped or ear-shaped corona, or pappus absent; pappus setae barbellate or ± plumose

Morphology Reproductive morphology Flowers Corolla

Corolla gamopetalous, of(3-)5 united petals, rarely absent; corolla ± regular and (3-)5-lobed (filiform or infundibuliform disk-florets), or bilabiate with a 2-lobed inner lip and a 3-dentate outer lip, or radiate with an abaxial strap-shaped limb (ray) 0–3(4)-dentate at the apex (ray-florets), or ligulate with a strap-shaped limb (ligule) 5-dentate at the apex

Morphology Reproductive morphology Flowers Androecium

Stamens (3-)5, filaments free, inserted on the corolla tube, contractile; anthers introrse, usually apically appendaged, usually laterally connate into a cylinder around the style, thecae rounded sagittate or tailed at the base; pollen usually echinate, sometimes echinolophate or lophate

Morphology Reproductive morphology Flowers Gynoecium

Style of hermaphrodite or functionally male florets elongating within the anther tube, shallowly to deeply bifid, occasionally undivided in functionally male florets, style arms with stigmatic areas on their inner sides and acute rounded or truncate at the apex, or the arms produced beyond the stigmatic surfaces as triangular, subulate or clavate appendages, variously papillate or hairy, usually with a brush of collecting hairs that sweep the pollen from the anther tube; style of female florets simpler, with acute to rounded style arms and without sweeping hairs

Morphology Reproductive morphology Fruits

Fruit unilocular, 1-seeded, indehiscent (usually an achene), rarely fleshy with the single seed enclosed in a hard endocarp (drupe), sometimes produced apically into a beak (rostrum), crowned by the persistent or caducous pappus, or epappose; endosperm absent or vestigial

Morphology Reproductive morphology Flowers

The floret sexual state, its corolla form, and the combination of floret types on the common receptacle distinguish capitula as follows:Capitula homogamous discoid - all florets of one sexual state, all hermaphrodite (or all female or functionally male); all corollas of the same form and ± regular Flowers (florets) small, 1–500 or more per capitulum, hermaphrodite or unisexual (female, male or functionally male), or neuter (sterile); ovary inferior, of 2 united carpels, unilocular with 1 erect basal ovule; perianth epigynous

Compositae, H. J. Beentje, M.Sc., Ph.D., F.L.S.. Flora of Tropical East Africa. 2000

Morphology General Habit

Herbs, subshrubs, shrubs or less often trees, sometimes lianes, rarely aquatic or epiphytic, sometimes succulent; tissues with schizogenous resin-ducts or articulated laticifers; polyfructosans (notably inulin), polyacetylenes and sesquiterpene lactones commonly present, some with pyrrolizidine alkaloids

Morphology Leaves

Leaves alternate or opposite, rarely whorled, usually simple but often lobed or divided

Morphology Reproductive morphology Inflorescences

Inflorescence a capitulum surrounded by an involucre of one or more series of protective bracts (phyllaries), the capitula solitary or in cymose, often corymbiform inflorescences of various kinds, occasionally aggregated into compound secondary capitula or glomerules; common receptacle naked or with scales (paleae) or bristles subtending the flowers, sometimes fimbriate or alveolate

Morphology Reproductive morphology Flowers

Florets small, 1–500 or more, sessile or rarely subsessile on the common receptacle, perfect, pistillate, staminate or sterile; ovary inferior, of 2 united carpels, unilocular, with 1 erect basal ovule; ovule tenuinucellar, unitegmic; calyx represented by a pappus of awns, scales, bristles, hairs or a more or less crown-like, cup-shaped or ear-shaped structure or completely absent, never green and herbaceous; corolla gamopetalous, of (3–)5 united petals, more or less regular and equally or unequally (3–)5-lobed or variously zygomorphic, commonly bilabiate with usually 2-lobed inner and 3-lobed outer lip, ligulate with strap-shaped apically 5-toothed limb, or radiate with strap-shaped apically 3- or fewer-toothed abaxial ray, the different kinds variously disposed in the capitulum, commonly all bilabiate, all ligulate (ligulate capitulum), all regular and perfect (discoid capitulum), all regular with the inner perfect or functionally੒and the outer filiform and੐(disciform capitulum) or enlarged and sterile (radiant capitulum) or the central (disc corollas) regular and the outer (ray corollas) in one or more series radiate (radiate capitulum), rarely all੒or all੐and the plants dioecious, or only the inner੐-fertile and the outer functionally੒; stamens with filaments inserted on the corolla tube; anthers united into a tube around the style, dehiscence introrse, apically appendaged, rounded to sagittate or tailed at the base; pollen usually echinate, sometimes echinolophate or lophate; style elongating within the anther-tube and pushing out the pollen at its apex, usually divided into two style branches with stigmatic surfaces on their inner sides and rounded, truncate or variously appendaged at the apex

Morphology Reproductive morphology Fruits

Fruit unilocular, 1-seeded, indehiscent, usually an achene, rarely a drupe, crowned by the persistent to caducous pappus or epappose; endosperm vestigial

Timothy M. A. Utteridge and Laura V. S. Jennings (2022). Trees of New Guinea. Kew Publishing. Royal Botanic Gardens, Kew

Distribution

A large family of approximately of up to 25,000 species in 1600 genera, divided between 13 tribes (over 40 may be recognised after molecular studies). The family is cosmopolitan, but is rare in true tropical rain forests, and in New Guinea the family is particularly rich in montane and subalpine zones, though few of genera become trees. There are c. 45 genera with 230 species in New Guinea.

Morphology General Habit

Herbs, subshrubs, shrubs or less often trees, sometimes lianous, rarely epiphytic or aquatic. Leaves opposite or alternate, rarely whorled; tissues with schizogenous resin-ducts or articulated laticifers

Morphology Reproductive morphology Flowers

Flowers (florets) small, of one or more kinds, aggregated into a head (capitulum) surrounded by a protective involucre of bracts (phyllaries), sessile or subsessile on a receptacle, with or without subtending scales (paleae) or bristles; calyx (pappus) represented by awns, scales or ear-shaped structure or completely absent, never green and herbaceous; corolla gamopetalous, usually of 5 united petals, often actinomorphic, sometimes zygomorphic and bilabiate (3+2), pseudo-bilabiate (4+1), rayed (with a limb with 1–4 apical teeth), or ligulate with 5 apical teeth; stamens usually 5, inserted on corolla, anthers united into a tube; ovary inferior, ovule 1, styles elongating within anther-tube, dividing into 2 style-arms with stigmatic surfaces on inner sides

Morphology Reproductive morphology Fruits

Fruit indehiscent, 1-seeded, usually dry (achene or cypsela), rarely fleshy (drupe).