Asteraceae
Annual to perennial herbs, sometimes shrubs or trees, rarely epiphytes or climbers. Lvs usually opposite or alternate, sometimes whorled, often all basal, simple and entire to variously dissected, rarely compound; stipules 0. Fls (florets) commonly 5-merous, ⚥, neuter or unisexual, sessile, nearly always in compact heads (capitula) on a common receptacle, sometimes individually subtended by bracts (scales), the whole capitulum surrounded by few to many bracts, very rarely florets solitary in panicles or capitula reduced to 1 floret. Capitula solitary or few to numerous in dense or diffuse cymes, panicles or less often spikes, racemes or other infl. types. Calyx epigynous, modified as pappus of scales, awns or hairs, sometimes reduced to a small corona or 0. Corolla epigynous, actinomorphic and filiform or tubular, or zygomorphic with an extended limb (ligule), often the outer florets ligulate (ray florets) and the inner tubular (disc florets) or all florets either ligulate or tubular. Stamens as many as corolla lobes and alternate with them; filaments free; anthers 2-locular, usually connate into a tube, very rarely scarcely connate, dehiscing introrsely. Ovary inferior, 1-locular; style 2-fid, often undivided in ♂ florets; ovules solitary, anatropous. Fr. usually an achene, often crowned by a persistent pappus, rarely a drupe.
SYNOPSIS
- A. Subfam. ASTEROIDEAE.
- Latex 0. Involucre 1-5-(many)-seriate. Tubular florets with short corolla lobes. Style branches almost always each with 2 parallel bands of stigmatic surface. Anthers mostly obtuse, sometimes caudate or tailed.
- 1. Trib. ANTHEMIDEAE.
- Lvs usually alternate, rarely opposite, often scented. Involucral bracts in 2-few rows, free, often membranous in part. Receptacular scales present or 0. Capitula discoid or radiate, mostly yellow or white. Pappus reduced to a corona, auricle or 0:
- AchilleaAnthemisArgyranthemumArtemisiaCentipedaChamaemelumChrysanthemumCotulaDendranthemaLeptinellaLeucanthemumMatricariaSolivaTanacetumTripleurospermum
- 2. Trib. ASTEREAE.
- Lvs usually alternate, very rarely opposite, usually not scented. Involucral bracts in 2-several rows, free, usually herbaceous to chartaceous. Receptacular scales usually 0, very rarely present. Capitula usually radiate, sometimes discoid, yellow, white or anthocyanic. Pappus usually of hairs, sometimes reduced to scales, awns, a corona or 0:
- AsterBaccharisBellisBrachycomeCallistephusCalotisCelmisiaConyzaDamnameniaErigeronLageniferaOleariaPachystegiaPleurophyllumSolenogyneSolidagoVittadinia
- 3. Trib. CALENDULEAE
- Lvs usually alternate, rarely opposite, often scented. Involucral bracts in 1-3-(4) rows, usually partly membranous. Receptacular scales 0. Capitula radiate, usually white or yellow, rarely anthocyanic. Pappus 0:
- CalendulaChrysanthemoidesOsteospermum
- 4. Trib. EUPATORIEAE.
- Lvs usually opposite, rarely alternate or verticillate, scented or not. Involucral bracts in 2-many rows, free, herbaceous to chartaceous. Receptacular scales usually 0, rarely present. Capitula discoid, anthocyanic. Pappus usually of hairs, rarely reduced to scales or 0:
- AgeratinaAgeratumBartlettinaEupatoriadelphusEupatoriumLiatris
- 5. Trib. HELIANTHEAE.
- Lvs usually opposite, sometimes alternate, usually not scented. Involucral bracts in 1-few rows, usually free, very rarely connate, the outer usually herbaceous, the inner often membranous. Receptacular scales usually present, rarely 0. Capitula usually radiate, sometimes discoid, mostly yellow or white, rarely anthocyanic. Pappus of scales, awns, a corona or 0:
- AmbrosiaBidensCoreopsisCosmosDahliaGaillardiaGalinsogaHeleniumHelianthusMadiaRudbeckiaSigesbeckiaWedeliaXanthium
- 6. Trib. INULEAE.
- Lvs usually alternate, rarely opposite, usually not scented. Involucral bracts in (1)-2-many rows, free, membranous or herbaceous, sometimes radiating and coloured. Receptacular scales present or 0. Capitula usually discoid, sometimes radiate, yellow to orange or white. Pappus usually of hairs, sometimes of scales, rarely 0:
- AmmobiumAnaphalisCassiniaCraspediaDittrichiaEwartiaFilagoGnaphaliumHaastiaHelichrysumInulaLeucogenesLogfiaPseudognaphaliumPulicariaRaouliaStuartinaVellereophyton
- 7. Trib. SENECIONEAE.
- Lvs usually alternate, rarely opposite or verticillate, usually not scented. Involucral bracts in 1-2-(few) rows, free but often interlocked by overlapping margins, mostly herbaceous or chartaceous. Receptacular scales 0. Capitula radiate or discoid, mostly yellow, rarely white or anthocyanic. Pappus usually of hairs, rarely 0:
- AbrotanellaBrachyglottisDolichoglottisDoronicumErechtitesEuryopsOthonnaPericallisPetasitesSenecioTraversiaTussilago
- 8. Trib. TAGETEAE.
- Lvs opposite or alternate, usually scented. Involucral bracts in 1-2 rows, free to completely connate, membranous. Receptacular scales 0. Capitula radiate or discoid, usually yellow to orange, rarely white, brown, or red. Pappus of hairs, scales, awns, or 0:
- Tagetes
- B. Subfam. CICHORIOIDEAE.
- Latex present or 0. Involucre (1)-2-many-seriate. Tubular florets 0, or with elongated corolla lobes. Style branches each with a single stigmatic area. Anthers usually tailed or caudate.
- 9. Trib. ARCTOTEAE.
- Usually trailing herbs with whitish or silvery tomentum on lvs at least beneath. Latex usually 0. Capitula with bright orange or yellow (rarely red or purple or white) ray florets and usually dark disc florets. Involucral bracts not spinous, free or (Gazania) fused at base. Disc styles united almost to the apex. Pappus usually of 1-2 rows of scales:
- ArctothecaArctotisGazania
- 10. Trib. CARDUEAE.
- Usually spiny rosette herbs (thistles) with erect stems; tomentum often cobwebby. Latex 0. Capitula with tubular florets only, rarely the outer radiate; true ligules 0. Florets often purple, rarely white, yellow or blue. Involucral bracts often with a spinous terminal appendage, or sometimes hooked, free. Style bearing a bristly swollen collar below union of branches; branches appressed together or diverging at tips. Pappus usually of bristles, hairs or plumes, sometimes of many series of narrow scales, the inner longest:
- AcroptilonArctiumCarduusCarthamusCentaureaCirsiumCynaraOnopordumPtilostemonSilybum
- 11. Trib. ECHINOPEAE.
- Tufted herbs with 1-2-pinnatifid lvs. Latex 0. Capitula with only 1 floret, clustered together in globular heads. Floret tubular, blue or white. Involucral bracts not spinous, free, in 3-5 rows, the outer divided into bristles. Style branches divergent. Pappus of short bristles or scales:
- Echinops
- 12. Trib. LACTUCEAE.
- Usually rosette herbs; indumentum various. Latex milky. Florets all ligulate, mostly yellow, rarely purple, orange or blue. Involucral bracts free, usually in several imbricate series, not spinous. Style branches filiform, often recurved, divergent. Pappus usually of hairs, bristles, plumes, or 0, rarely of scales:
- ChondrillaCichoriumCrepisEmbergeriaHieraciumHypochoerisKirkianellaLactucaLapsanaLeontodonMicroserisMycelisPicrisSonchusTaraxacumTolpisTragopogon
- 13. Trib. VERNONIEAE:
- Usually herbs; latex usually 0. Capitula with tubular florets only, rarely the outer radiate; true ligules 0. Florets usually purple or pink. Involucral bracts free, not spinous. Style branches filiform, divergent. Pappus of hairs sometimes with expanded bases.
- Vernonia
KEY TO TRIBES
Key
c. 1100 genera, c. 25000 spp., cosmopolitan.
Asteraceae (alternative family name Compositae) is one of the largest flowering plant families, and there are more spp. of Asteraceae naturalised in N.Z. than of any other family in this Flora. Asteraceae contains surprisingly few food plants, but numerous spp. are grown for their colourful, often long-lived capitula. Numerous spp. also occur as weeds. Members of the Asteraceae are commonly known as composites or daisies.
A recent symposium provided much information on the biology of the family and also systematic reviews of each of the tribes [Heywood, V. H., Harborne, J. B. and Turner, B. L. (Eds), The Biology and Chemistry of the Compositae (1977)]; the arrangement of genera and tribes in that work is largely followed here. We provide a synopsis, a key to tribes as they occur in N.Z., and then treat each tribe separately with a key to genera following the description of each.
Capitula of all tribes with fully naturalised spp. are illustrated in Plate 8.