1!Angiosperms or Flowering Plants!the phylum Magnoliophyta!Land Plant Evolution:"Algae to Angiosperms "The greatest adaptive radiation . . . "• is the largest radiation of plants "• involves series of dramatic adaptations to the problem of life on land and being non-motile "• exhibits successive rounds of speciation and subsequent extinction"• sets the stage for the development of a land-based ecosystem with fungi and animals"Angiosperms - Flowering Plants!Angiosperms focus of the course"• comprise the phylum Magnoliophyta"• vast majority of plant diversity"What are the non-angiosperm land plants?"• DNA evidence has clarified much but not all of the relatioships of other phyla (= divisions)"See first pages of Chpts 1 & 3 for more detail (Plant Systematics)"Fungi? !• Fungi collectively are not a natural group"• More closely related to animals than to plants"2!Green Plants are here!Fungi are here!Fungi? !Traditional view of eukaryotic relationships!Katz et al. 2012"Systematic Biology !Fungi? !Turning the Crown Upside Down: Gene Tree Parsimony Roots the Eukaryotic Tree of Life !Charales - stoneworts!"• Green algal lineage"• Closest relatives to land plants"Extinct Land Plants - the first plants"Ordovician Period (505 - 440 mya)"• First evidence of land life at 460 mya"Microfossils of spores with sporopollenin (degradation resistant material like lignin) and similar to modern day bryophytes such as liverworts"Found worldwide in shales that were deposited at the marine-terrestrial interface"3!bryophytes!• earliest land plants - non vascular"• gametophyte dominant, 16000 species"• 3 lineages — they are not a natural group"hornworts" mosses" mosses"liverworts"liverworts"Liverworts - Marchantiophyta "Mosses - Bryophyta"Hornworts - Anthoceratophyta "bryophytes!Rhynia seen in the early Devonian (Rhynie Chert fossil) is one of first vascular plants"20 cm tall, no roots, no leaves, primitive vascular tissue"Extinct Land Plants - first vascular plants"Early Devonian Period (410 - 390 mya)"Lycopodiophyta - club mosses!• 3 families, 1150 species"• sporophyte dominant, vascular, free sporing"• they are sister to all other vascular plants"Isoetes - quillworts"Selaginella - spike mosses"Lycopodium - club mosses"4!First true ferns [Protopteridium] - free sporing with complex sporangia & megaphylls"Extinct Land Plants - the first ferns"Late Devonian Period (390 - 360 mya)"Polypodiophyta - ferns!• 11000 species"• immense variation in habit and habitat"• spores produced in specialized sporangia"• need a lot of systematic work - tropics!"• includes the horsetails as unusual ferns!"• 15 species in Equisetum"• vascular plants, reduced leaves, terminal sporangia"Polypodiophyta - ferns!• includes the strange whish ferns!"• 6 species in 2 genera"• vascular plants, leafless green stemmed, lateral sporangia"Psilotum habit" Psilotum branch" Psilotum sporangia"Polypodiophyta - ferns!5!Late Devonian Period (390 - 360 mya)"First “seeds” - “seed ferns” [Archaeosperma]""Plants fern-like with dissected compound leaves, but produce naked seeds (embryo within protective coverings)"Extinct Land Plants - the seed plants""• Big trees with net-veined leaves"• Seed bearing (derived from female gametophyte) and pollen forming (from male gametophyte)"Permian Period (286 - 245 mya)"Extinct Land Plants – first gymnosperms"Pinophyta - gymnosperms!conifers"• 870 species"• seed plants but seeds naked"• often divided into 4 phyla"• is one closer to angiosperms?"juniper"spruce"pine"cycads"Pinophyta - gymnosperms!• 870 species"• seed plants but seeds naked"• often divided into 4 phyla"• is one closer to angiosperms?"female strobili"male strobilus"6!ginkgo"Pinophyta - gymnosperms!• 870 species"• seed plants but seeds naked"• often divided into 4 phyla"• is one closer to angiosperms?"male strobili"mature seeds"gnetophytes"Pinophyta - gymnosperms!• 870 species"• seed plants but seeds naked"• often divided into 4 phyla"• is one closer to angiosperms?"Welwitschia mirabilis!Ephedra!Gnetum!Triassic"Near the Jurassic/Cretaceous border, the first Angiosperms are seen""Archaefructus"Extinct Land Plants – first flowering plants"Cretaceous Period (146 - 65 mya)"• 275,000 + species"• seed plants with seeds encased in ovary "• flowers a “key innovation”"Magnoliophyta - angiosperms!7!Angiosperms - Flowering Plants!• tremendous adaptive radiation on land (and back into water)"Angiosperms - Flowering Plants!• tremendous adaptive radiation on land (and back into water)"• Eucalyptus regnans (Myrtaceae) over 100m tall and 19m dbh"Eucalyptus regnans (Myrtaceae) -Tasmania"Angiosperms - Flowering Plants!• tremendous adaptive radiation on land (and back into water)"• Wolffia microscopica (Araceae) less than 1mm long"0.1 mm"Angiosperms - Flowering Plants!• tremendous adaptive radiation on land (and back into water)"• Rafflesia arnoldii (Rafflesiaceae) from New Guinea, up to 1m across and 20lbs"8!Angiosperms - Flowering Plants!• tremendous adaptive radiation on land (and back into water)"• largest inflorescence Amorphophallus titanum (Araceae)"Angiosperms - Flowering Plants!• tremendous adaptive radiation on land (and back into water)"• largest numbers of flowers — Corypha palm"Magnoliophyta classification""• previously divided into two classes — dicots and monocots"Angiosperms - Flowering Plants!• artificial!"• we will use Angiosperm Phylogeny Group (APG III) classification system of 2009"The Flower — Why Important?!1. unlike anything else in other plants & extremely variable & co-evolved with animals"2. floral features used in describing and idʼing "3. plant specimens (herbarium) must include flowers or derived features"4. classification of angiosperms relies on flowers"The Flower: most significant feature of angiosperms"Calochortus - fairy lanterns & mariposas (images: T. Givnish)"9!The Flower — What is it?!• specialized shoot = stem + leaves (folia)!• shoot is highly modified and determinate (ceased to grow)"The Flower — What is it?!from Schleiden 1855"• “foliar theory” of flower - J.W. von Goethe in “Attempt to Interpret the Metamorphosis of Plants” (1790)"The Flower —