Diversity and EvolutionDiversity and Evolutionofof Asterids Asterids. . . asters,. . . asters, ragweeds ragweeds, and, andgoldenrods . . .goldenrods . . .AsteralesAsteraleslamiidslamiidscampanulidscampanulids•• 11 families and nearly 26,000 species - 11 families and nearly 26,000 species -AustralasiaAustralasia appears to be center of appears to be center ofdiversitydiversity•• no no iridoidsiridoids, latex common, latex common, inferior, inferiorgynoeciumgynoecium, pollen presentation, pollen presentationinferior Ginferior Gbellflower -bellflower -CampanulaceaeCampanulaceaechickorychickory - -AsteraceaeAsteraceaeAsteraceaeAsteraceae - composites - compositesOne of the most successful of all flowering plant families withOne of the most successful of all flowering plant families withover 1,500 genera and 23,000 species!over 1,500 genera and 23,000 species!•• composites found throughout the composites found throughout theworld but most characteristic ofworld but most characteristic ofthe grassland biomesthe grassland biomesAsteraceaeAsteraceae - composites - compositesOne of the most successful of all flowering plant families withOne of the most successful of all flowering plant families withover 1500 genera and 23,000 species.over 1500 genera and 23,000 species.•• but also diverse in arctic to but also diverse in arctic totropical and subtropical regionstropical and subtropical regionsAsteraceaeAsteraceae - composites - compositesFamily has 3 specializedFamily has 3 specializedfeatures important infeatures important inthis radiation:this radiation:1.1.Special inflorescenceSpecial inflorescence““headhead”” - - pseudanthiapseudanthia2.2.Pollen presentationPollen presentation3.3.Diverse Diverse secondarysecondarychemistrychemistryPseudanthia Pseudanthia in the in the AsteridsAsteridsCornaceaeCornaceaeApiaceaeApiaceaeRubiaceaeRubiaceaeAsteraceaeAsteraceaeCaprifoliaceaeCaprifoliaceaeCaprifoliaceaeCaprifoliaceaePathway to Pathway to Asteraceae Asteraceae Head?Head?AsteraceaeAsteraceaeCalyceraceaeCalyceraceaeGoodeniaceaeGoodeniaceaeMenyanthaceaeMenyanthaceaePozner Pozner et al. 2012 (et al. 2012 (Amer Amer J Bot)J Bot)Pathway toPathway to Asteraceae Asteraceae Head? Head?Pollination SyndromesPollination SyndromeswaspwaspfliesfliesmothsmothsbeesbeesbutterfliesbutterflieswindwindPollen PresentationPollen PresentationPollen pushed out by aPollen pushed out by astyle that acts as a plungerstyle that acts as a plungerCross pollinationCross pollinationon inner receptiveon inner receptivesurfacessurfacesSelf pollinationSelf pollinationby curling ofby curling ofstigmasstigmasStigma makes contact withStigma makes contact withself pollen if necessaryself pollen if necessaryAnthers fused forming aAnthers fused forming atube for pollen releasetube for pollen releaseChemical DiversityChemical Diversity•• polyacetylenes polyacetylenes,, sequiterpene sequiterpene lactones, lactones, terpenes terpenes,,alkaloids, latexalkaloids, latexPackeraPackeraAgoserisAgoserisTanacetumTanacetumChemical DiversityChemical Diversity•• sequiterpene sequiterpene lactones poisonous tolactones poisonous tosheep in the southern Rockiessheep in the southern Rockies•• ““spewingspewing”” disease diseaseHelenium hoopesii Helenium hoopesii –– SneezeweedSneezeweed,,OwlOwl’’s-claws-clawChemical DiversityChemical Diversity•• sequiterpene sequiterpene lactones used in anti-lactones used in anti-malarial treatmentmalarial treatment•• Chinese herbal medicine Chinese herbal medicineArtemisia Artemisia annua annua –– Sweet wormwoodSweet wormwoodAsteraceaeAsteraceae - composites - compositesThe The headhead or or capitulumcapitulum is a cluster is a clusterof 1 or 2 distinct flower types.of 1 or 2 distinct flower types.The family is also calledThe family is also called““CompositaeCompositae”” referring to this referring to thisclustering.clustering.The head is surrounded by special bractsThe head is surrounded by special bractscalled thecalled the involucreinvolucre or or phyllariesphyllaries..TheThe involucre involucre is important in the is important in theclassification and identification within theclassification and identification within thefamily.family.AsteraceaeAsteraceae - floral diversity - floral diversityCA X CA X CO (5) A (5)CO (5) A (5) G (2) G (2)____•• Calyx is reduced to a Calyx is reduced to a pappuspappus of ofscales, awns, bristles, or absentscales, awns, bristles, or absent•• Corolla has 5 petals but Corolla has 5 petals butvariously fused orvariously fused or zygomorphic zygomorphic•• Anthers (only) fused in a ring Anthers (only) fused in a ringAsteraceaeAsteraceae - floral diversity - floral diversity•• the family exhibits a diverse array of floral types the family exhibits a diverse array of floral typesDisc floretDisc floretTrue RayTrue RayLigulateLigulate floret floret•• these three corolla types are seen in Wisconsin these three corolla types are seen in WisconsinAsteraceaeAsteraceae - floral diversity - floral diversity 1. 1. DiskDisk or or tubulartubular florets are florets are actinomorphic actinomorphic11Main floret typesMain floret typesAsteraceaeAsteraceae - floral diversity - floral diversity 1. 1. DiskDisk or or tubulartubular florets are florets are actinomorphic actinomorphic 2. 2. RayRay florets are usually 3 long fused petals + 2 obsolete petals florets are usually 3 long fused petals + 2 obsolete petals2211Main floret typesMain floret typesAsteraceaeAsteraceae - floral diversity - floral diversity 1. 1. DiskDisk or or tubulartubular florets are florets are actinomorphic actinomorphic 2. 2. RayRay florets are usually 3 long fused petals + 2 obsolete petals florets are usually 3 long fused petals + 2 obsolete petals 3. 3. LigulateLigulate florets are 5 fused petals but split open florets are 5 fused petals but split open332211Main floret typesMain floret typesAsteraceaeAsteraceae - floral diversity - floral diversityThe fruit is a one-seededThe fruit is a one-seeded acheneachene with the with thepappuspappus serving as the fruit disperser serving as the fruit disperser(e.g., barbs for animal dispersal, hairs for(e.g., barbs for animal dispersal, hairs forwind dispersal)wind dispersal)CA X CA X CO (5) A (5)CO (5) A (5) G (2) G (2)____AsteraceaeAsteraceae - head diversity - head diversityThese various types of florets combineThese various