Land Plant Evolution: Land Plant Evolution: Algae to Angiosperms Algae to Angiosperms The greatest adaptive radiation . Angiosperms - flowering plants - focus of the course • is the largest radiation of • comprise the phylum Magnoliophyta plants • contains majority of plant diversity • involves series of dramatic adaptations to the problem of life on land and being non- What are the non-angiosperm land plants? motile • DNA evidence has clarified much but not all • exhibits successive rounds of the relationships of other phyla of speciation and subsequent extinction • sets the stage for the See first pages of Chpts 1 & Chpts 3-4 for more detail development of a land-based (Plant Systematics, 2nd ed.) – Know the phyla of land ecosystem with fungi and animals plants Fungi? Fungi? • Fungi collectively are not a natural group • More closely related to animals than to plants Recent view of eukaryotic take Botany 332 – spring 2020 relationships • root is in microbes with fungi/animals/plants forming a crown radiation Fungi are here Green Plants are here we are here 1 Charales - stoneworts Charales - stoneworts • Green algal lineage take Botany 330 – fall 2020 • Green algal lineage take Botany 330 – fall 2020 • Closest relatives (?) to land plants [embryophytes] • Closest relatives (?) to land plants [embryophytes] Starry stonewort Nitellopsis obtusa L. Wisconsin’s latest (and greatest?) lake invasive Charales - stoneworts Extinct Land Plants - the first plants Ordovician Period (505 - 440 mya) take Botany 330 – fall 2020 • Green algal lineage • First evidence of land life at 460 mya • Closest relatives (?) to land plants [embryophytes] Microfossils of spores with sporopollenin (degradation resistant material like lignin) and similar to modern day bryophytes such as liverworts Starry stonewort Nitellopsis obtusa L. Found worldwide in shales that were deposited at the marine-terrestrial interface Wisconsin’s latest (and greatest?) lake invasive 2 bryophytes bryophytes • earliest land plants - non vascular • gametophyte dominant, 16000 species • 3 lineages — they are not a natural group hornworts mosses mosses Liverworts - Marchantiophyta Mosses - Bryophyta Hornworts - Anthoceratophyta liverworts liverworts Extinct Land Plants - first vascular plants Lycopodiophyta - club mosses Early Devonian Period (410 - 390 mya) • 3 families, 1150 species Rhynia seen in the early Devonian (Rhynie • sporophyte dominant, vascular, free sporing Chert fossil) is one of first vascular plants • they are sister to all other vascular plants 20 cm tall, no roots, no leaves, primitive vascular tissue Lycopodium - club mosses Isoetes - quillworts Selaginella - spike mosses 3 Extinct Land Plants - the first ferns Polypodiophyta - ferns Late Devonian Period (390 - 360 mya) • 11000 species (or called “Monilophyta”) • immense variation in habit and habitat • spores produced in specialized sporangia • need a lot of systematic work - tropics! First true ferns [Protopteridium] - free sporing with complex sporangia & megaphylls Polypodiophyta - ferns Tropical FERNS AND LYCOPHYTES • includes the horsetails as unusual ferns! • 15 species in Equisetum • vascular plants, reduced leaves, terminal sporangia © J.J.Pucci Dr. Robbin Moran New York Botanical Garden Where: La Selva and Las Cruces Dr. James Watkins Biological Stations - Costa Rica Colgate University this was When: Jan 4—20, 2019 Plus invited faculty: Latest arrival Jan 3, Latest departure Jan 23 Dr. Alejandra Vasco Botanical Research Institute of Texas your chance 4 Polypodiophyta - ferns Extinct Land Plants - the seed plants • includes the strange whisk ferns! Late Devonian Period (390 - 360 mya) • 6 species in 2 genera First “seeds” - “seed ferns” [Archaeosperma] • vascular plants, leafless green stemmed, Plants fern-like with dissected compound leaves, lateral sporangia but produce naked seeds (embryo within protective coverings) Psilotum habit Psilotum branch Psilotum sporangia Extinct Land Plants – first gymnosperms Pinophyta - gymnosperms Permian Period (286 - 245 mya) • 870 species • seed plants but seeds naked • often divided into 4 phyla conifers • Big trees with net-veined • is one closer to angiosperms? leaves • Seed bearing (derived from female gametophyte) and pollen forming (from male gametophyte) pine spruce juniper 5 Pinophyta - gymnosperms Pinophyta - gymnosperms • 870 species • 870 species • seed plants but seeds naked • seed plants but seeds naked • often divided into 4 phyla • often divided into 4 phyla • is one closer to angiosperms? • is one closer to angiosperms? mature seeds ginkgo cycads male strobili male strobilus female strobili Pinophyta - gymnosperms Extinct Land Plants – first flowering plants • 870 species Cretaceous Period (146 - 65 mya) • seed plants but seeds naked Near the Jurassic/Cretaceous border, the • often divided into 4 phyla first Angiosperms are seen • is one closer to angiosperms? gnetophytes Gnetum Triassic Ephedra Welwitschia mirabilis Archaefructus 6 Magnoliophyta - angiosperms Angiosperms - Flowering Plants • tremendous adaptive radiation on land (and back into water) • 275,000 + species (400,000 ?) • seed plants with seeds encased in ovary • flowers a “key innovation” Angiosperms - Flowering Plants Angiosperms - Flowering Plants • tremendous adaptive radiation on • tremendous adaptive radiation on land (and back into water) land (and back into water) • Eucalyptus regnans • Wolffia microscopica (Myrtaceae) over 100m tall and (Araceae) less than 1mm long 19m dbh Eucalyptus regnans (Myrtaceae) -Tasmania 0.1 mm 7 Angiosperms - Flowering Plants Angiosperms - Flowering Plants • tremendous adaptive radiation on • tremendous adaptive radiation on land (and back into water) land (and back into water) • Wolffia microscopica • largest inflorescence (Araceae) less than 1mm long Amorphophallus titanum (Araceae) • Amorphophallus titanum (Araceae) over 2 m tall Angiosperms - Flowering Plants Angiosperms - Flowering Plants • tremendous adaptive radiation on • tremendous adaptive radiation on land (and back into water) land (and back into water) • largest numbers of flowers — • largest flower: Rafflesia arnoldii Corypha palm (Rafflesiaceae) from New Guinea, up to 1m across and 20lbs 8 Angiosperms - Flowering Plants Angiosperms or Flowering Plants the Phylum Magnoliophyta Magnoliophyta classification Today & Monday: overview of the morphology • previously divided into two and evolution of the flower – optionally read first classes — dicots and monocots part of Chpt. 6 in Plant Systematics, 2nd ed. – available at Canvas/Learn@UW • artificial! Lab next two weeks: (1) vegetative features • we will use Angiosperm & conifers – 1st half of Chpt 9 in Plant Phylogeny Group (APG III) Systematics; (2) finish overview of flower classification system of 2009 and examine floral, fruit, & inflorescence diversity – 2nd half of Chpt. 9 9.