Asterales Diversity and Evolution of Asterids asters ragweeds ragweeds and goldenrods 11 families and nearly 26 000 species Australasia appears to be center of diversity lamiids no iridoids iridoids latex common common inferior gynoecium gynoecium pollen presentation campanulids inferior G bellflower Campanulaceae chickory Asteraceae Asteraceae composites Asteraceae composites One of the most successful of all flowering plant families with over 1 500 genera and 23 000 species One of the most successful of all flowering plant families with over 1500 genera and 23 000 species composites found throughout the world but most characteristic of the grassland biomes but also diverse in arctic to tropical and subtropical regions Asteraceae composites Pseudanthia in the Asterids Family has 3 specialized features important in this radiation 1 Special inflorescence head head pseudanthia Cornaceae Asteraceae Apiaceae Caprifoliaceae Rubiaceae Caprifoliaceae 2 Pollen presentation 3 Diverse secondary chemistry Pathway to Asteraceae Head Menyanthaceae Goodeniaceae Calyceraceae Pathway to Asteraceae Head Asteraceae Pozner et al 2012 Amer Amer J Bot Pollination Syndromes wasp flies bees Pollen Presentation moths butterflies wind Cross pollination on inner receptive surfaces Anthers fused forming a tube for pollen release Chemical Diversity Packera Agoseris Tanacetum polyacetylenes polyacetylenes sequiterpene lactones terpenes terpenes alkaloids latex Pollen pushed out by a style that acts as a plunger Self pollination by curling of stigmas Stigma makes contact with self pollen if necessary Chemical Diversity Helenium hoopesii Sneezeweed Sneezeweed Owl Owl s claw sequiterpene lactones poisonous to sheep in the southern Rockies spewing spewing disease Chemical Diversity Asteraceae composites The head or capitulum is a cluster of 1 or 2 distinct flower types The family is also called Compositae Compositae referring to this clustering Artemisia annua Sweet wormwood The head is surrounded by special bracts called the involucre or phyllaries phyllaries sequiterpene lactones used in antimalarial treatment Chinese herbal medicine The involucre is important in the classification and identification within the family Asteraceae floral diversity CA X CO 5 A 5 G 2 Calyx is reduced to a pappus of scales awns bristles or absent Corolla has 5 petals but variously fused or zygomorphic Anthers only fused in a ring Asteraceae floral diversity Disc floret True Ray the family exhibits a diverse array of floral types these three corolla types are seen in Wisconsin Ligulate floret Asteraceae floral diversity 1 Asteraceae floral diversity 1 2 Main floret types Main floret types 1 Disk or tubular florets are actinomorphic 1 Disk or tubular florets are actinomorphic 2 Ray florets are usually 3 long fused petals 2 obsolete petals Asteraceae floral diversity 1 3 Asteraceae floral diversity CA X CO 5 A 5 G 2 2 Main floret types 1 Disk or tubular florets are actinomorphic 2 Ray florets are usually 3 long fused petals 2 obsolete petals 3 Ligulate florets are 5 fused petals but split open The fruit is a one seeded achene with the pappus serving as the fruit disperser e g barbs for animal dispersal hairs for wind dispersal Asteraceae head diversity These various types of florets combine to form a number of different looking heads Asteraceae head diversity These various types of florets combine to form a number of different looking heads Radiate head head disk florets in the center ray florets along the edge these usually pistillate pistillate Radiate head head disk florets in the center ray florets along the edge these usually pistillate pistillate Discoid head head only disk or tubular florets comprise the entire head Aster aster Asteraceae head diversity Liatris blazing star Asteraceae phylogeny early DNA based work surprisingly placed a small group of South America genera as sister to the rest of the family and recognition of 3 subfamilies and many tribes These various types of florets combine to form a number of different looking heads Radiate head head disk florets in the center ray florets along the edge these usually pistillate pistillate Discoid head head only disk or tubular florets comprise the entire head Ligulate head head only ligulate florets comprise the entire head Cichorium chickory Barnadesia lanceolata Asteraceae phylogeny later DNA based work questioned the monophyly of subfamily Cichorioideae classification still in progress Asteraceae phylogeny family originated in South America Asteraceae phylogeny family originated in South America Asteraceae tribes Tribe Barnadesiinae Small South American tribe with bilabiate C or pseudolabiate D corolla similar to some other families of Asterales disk Barnadesia lanceolata ray ligulate Asteraceae tribes Asteraceae tribes Tribe Mutisieae Tribe Lactuceae Cichorieae Cichorieae Only have ligulate heads heads milky latex in vegetative parts pappus of filaments South American tribe usually with bilabiate flowers characteristic of tepuis in northern South America Dandelion goat goat s beard chickory chickory hawkweed Taraxacum dandelion Stomochaeta Duidaea Asteraceae tribes Tribe Lactuceae Cichorieae Cichorieae Cerro Autana Asteraceae tribes Tribe Lactuceae Cichorieae Cichorieae Hieracium hawkweeds Cichorium intybus chickory Eurasian weed totally naturalized and distributed widely even to Botany 400 plant collections Krigia biflora false dandelion Asteraceae tribes Asteraceae tribes Tribe Cardueae Cynareae Cynareae Tribe Cardueae Cynareae Cynareae spiny phyllaries and often leaves and stems Cirsium thistles heads never radiate petals white or cynanic colors blues purples thistle knapweed burdock Centaurea maculosa Spotted knapweed Asteraceae tribes Tribe Vernonieae Alternate leaves Purple flowers generally Hesperomannii Hawaii Arctium burdock Asteraceae tribes Tribe Inuleae Gnaphalieae Gnaphalieae Plants usually covered with white hairs pappus of bristles or hairs Pussy toes cudweed pearly everlasting Antennaria plantaginifolia pussy toes Vernonia fasciculata ironweed Asteraceae tribes Asteraceae tribes Tribe Astereae Tribe Inuleae Gnaphalieae Gnaphalieae Conspicuous rays in radiate head pappus of plumose bristles asters goldenrods fleabanes Anaphalis margaritacea pearly everlasting Asteraceae tribes Tribe Astereae Aster pilosus frost aster Botany 400 plant collections Aster novae angliae novae angliae New England aster Asteraceae tribes Tribe Anthemideae Aromatic plants with