Diversity and EvolutionDiversity and Evolutionof Asteridsof Asterids. . . dogwoods, blueberries, and. . . dogwoods, blueberries, andprimroses . . .primroses . . .AsteridsAsterids•• continue survey through the eudicots continue survey through the eudicotsor tricolpates after completing Rosidsor tricolpates after completing Rosids•• the Asterids are the second of the two the Asterids are the second of the twolarge groups of dicots and the easier onelarge groups of dicots and the easier oneto define morphologicallyto define morphologicallyrosidrosidasteridasteridAsterid CharacteristicsAsterid Characteristics•• fused petals - fused petals - sympetalysympetaly•• stamen number stamen number << petal number petal number•• stamens fused to corolla tube stamens fused to corolla tubeAsterid CharacteristicsAsterid Characteristics•• iridoidiridoid compounds (with losses) compounds (with losses)Picrorhiza kurroaPicrorhiza kurroaGardeniaGardenia•• ‘‘basal asteridsbasal asterids’’ have them (previously not placed with have them (previously not placed withasterids)asterids)RubiaceaeRubiaceaecoffee familycoffee familyScrophulariaceaeScrophulariaceaesnapdragon familysnapdragon familyAsterid CharacteristicsAsterid Characteristics•• one layer of integumentsone layer of integuments in ovule vs. two in other groups in ovule vs. two in other groupsbitegminaebitegminae•• the the ““unitegminaeunitegminae”” (vs. bitegminae) of van Tieghem in (vs. bitegminae) of van Tieghem in1901 = new Asterid group!1901 = new Asterid group!Asterid CompositionAsterid Composition•• composition of composition of AsteridsAsterids is largely is largelycongruent with previous morphologycongruent with previous morphologyAsterid CompositionAsterid Composition•• exceptions include the exceptions include the ‘‘basal asteridsbasal asterids’’and separate petal or small flower ordersand separate petal or small flower ordersApiaceae - carrot familyApiaceae - carrot familyAquifoliaceae - holly familyAquifoliaceae - holly familyAsterid CompositionAsterid Composition•• exceptions include the exceptions include the ‘‘basal asteridsbasal asterids’’and separate petal or small flower ordersand separate petal or small flower orders•• some of these some of these ““nonnon”” sympetalous sympetalousAsterids (e.g., order Cornales) haveAsterids (e.g., order Cornales) have““earlyearly”” petal ring primordia petal ring primordia in indevelopmentdevelopment•• subsequent petal development is subsequent petal development isseparate, so appear to be polypetalousseparate, so appear to be polypetalousEarly ring primordia of 5 petals inEarly ring primordia of 5 petals insnapdragon (a true asterid) snapdragon (a true asterid) [EMBO Journal (2003)[EMBO Journal (2003)22: 105822: 1058––1066]1066]Basal AsteridsBasal Asterids•• basal asterids represent a basal asterids represent a gradegradetowards the core asteridstowards the core asterids•• the the ““standardstandard”” Asterid flower has not Asterid flower has notbeen fixedbeen fixed•• great great variation in floral formvariation in floral form in the two in the twoorders Cornales and Ericalesorders Cornales and EricalesCornusCornusChimaphilaChimaphilaCornalesCornales•• order sister to remainder of Asterids, order sister to remainder of Asterids,comprises 7 small families (diverse)comprises 7 small families (diverse)CornaceaeCornaceaeLoasaceaeLoasaceaeNyssaceaeNyssaceaeHydrangeaceaeHydrangeaceae*Cornaceae - dogwoods*Cornaceae - dogwoods•• mainly north temperate shrub family of 2 genera and 85 species mainly north temperate shrub family of 2 genera and 85 speciesAlangiumAlangiumCornusCornus*Cornaceae - dogwoods*Cornaceae - dogwoods•• opposite, simple leaves opposite, simple leaves•• arcuatearcuate venation venation*Cornaceae - dogwoods*Cornaceae - dogwoodsCA 4 CO 4 A 4 G (2)CA 4 CO 4 A 4 G (2) __ __•• 4 merous4 merous, small flowers with, small flowers withseparate petalsseparate petals•• 2 carpellate 2 carpellate inferiorinferior ovary ovary•• fruit a 2-seeded fruit a 2-seeded ‘‘drupedrupe’’bractsbracts•• some inflorescences surrounded some inflorescences surroundedby by showy bractsshowy bracts•• ““headhead”” oror ““pseudanthiumpseudanthium”” (false(falseflower)flower)Cornus stoloniferaCornus stolonifera - red osier - red osier*Cornaceae - dogwoods*Cornaceae - dogwoodsEastern North AmericanEastern North Americansmall tree with 4small tree with 4conspicuous white bractsconspicuous white bractsCornus floridaCornus florida - flowering dogwood - flowering dogwood*Cornaceae - dogwoods*Cornaceae - dogwoodsLow to ground borealLow to ground borealsubshrub, appears to have asubshrub, appears to have awhorl of leaves, and has 4whorl of leaves, and has 4showy bracts below flowersshowy bracts below flowersCornus canadensisCornus canadensis - bunch berry - bunch berry*Cornaceae - dogwoods*Cornaceae - dogwoodsCommon in wet places,Common in wet places,distinctive with red stemsdistinctive with red stemsCommon component ofCommon component ofshrub carrshrub carrCornus racemosaCornus racemosaGray dogwoodGray dogwoodCornus stoloniferaCornus stoloniferaRed-osierRed-osierNyssa sylvaticaNyssa sylvatica - sour gum, black - sour gum, blackgum, black tupelogum, black tupelo•• rare, flowers unisexual rare, flowers unisexualwith male flowers inwith male flowers inumbels; drupes blackumbels; drupes blackNyssaceae - black gumsNyssaceae - black gumsClosely related to dogwood family, small familyClosely related to dogwood family, small familyof trees and shrubs from North Temperate regionof trees and shrubs from North Temperate regionHydrangeaceae - hydrangeasHydrangeaceae - hydrangeasPhiladelphus -Philadelphus -mock orangemock orangeHydrangea arborescensHydrangea arborescensAnother small family of trees, shrubs, and vines from NorthAnother small family of trees, shrubs, and vines from NorthTemperate region - many ornamental woody plantsTemperate region - many ornamental woody plants•• most recently placed in most recently placed inSaxifragaceaeSaxifragaceaeHydrangeaHydrangeaLoasaceae Loasaceae –– evening stars evening starsMentzelia crocea Mentzelia crocea –– Sierra blazing starSierra blazing starAnother small family related to hydrangeas but largelyAnother small family related to hydrangeas but