Beginning Grass Identification Workshop Mike Bauer July 2018 University of Arizona Herbarium Arizona Native Plant Society !1 ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona Overview Day 1 S. McMahon: • UA Herbarium • Introduction to grasses M. Bauer: • Grass morphology, identification skills and practice keying Day 2 M. Bauer: • Grass identification skills and more practice keying !2 ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona UA Herbarium ARIZ • 435,000 specimens • Arizona well represented (1/3 of total) 4230 taxa in 153 families • Grasses: 50,000 specimens 40,700 database records 563 Arizona taxa 450 Pima Co. taxa (7000 records) !3 ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona UA Herbarium ARIZ People: • Shelley McMahon • George Ferguson • Mima Falk • Betsy Arnold, Curator of Fungi, Robert L. Gilbertson Mycological Herbarium !4 ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona UA Herbarium ARIZ People, cont.: • Mike Bauer • Ries Lindley • Ellen Dorn • Sue Carnahan • Richard Felger • Dave Bertelsen and several additional volunteers, associated researchers, and students !5 ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona Grasses on the planet Poaceae 12,074 spp., 771 genera Worldwide, over vast areas, e.g., grasslands drier temperate and tropics before humans, estimated at ~24% land surface Miocene origins (~20 mya) correlated with other radiations (grazers, umbels, comps) !6 ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona Arizona grasslands !7 http://azconservation.org/projects/grasslands ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona Grasses in our lives Poaceae 70% of farmland, >50% human calorie intake, cult. ~10k yrs wheat, rice, corn, sugarcane, ... !8 ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona Grass relatives Monocots: flower parts in multiples of three Grasses are Monocots Magnoliids: Eudicots: spiral flower parts or 3-merous usually 4- or 5-merous !9 ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona Grass relatives Grasses are Monocots Magnoliids Eudicots !10 ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona Grass relatives “Phylogeny”: • our best guess* at what happened in history • reports ancestry and character changes Magnoliids Monocots Eudicots common ancestor of all flowering plants (~150 mya) !11 ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona Grass morphology: architecture typical plant body !12 ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona Grass morphology: architecture grass plant body !13 ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona Grass morphology: architecture typical plant body grass plant body Corresponding parts: flowers leaves nodes internodes !14 ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona Grass morphology: architecture typical plant body grass plant body Other than in the roots, grass plant architecture is fairly typical !15 ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona Grass morphology: stems jointed stems, i.e., prominent nodes 2-ranked leaves (“distichous”) !16 ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona Grass morphology: leaves Monocot leaf venation: parallel (or penni-parallel) veins !17 ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona Grass morphology: leaves monocots non-monocots !18 ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona Grass morphology: leaves Grasses (and other monocots) monocots have unusual leaf growth, non-monocots from the middle. So, they can be mowed or grazed. !19 http://www.vcbio.science.ru.nl/en/virtuallessons/leaf/formation/ ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona Grass morphology: leaves Grasses: like other monocots but lower portion forms a sheath !20 ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona Grass morphology: leaves Grass-specific terminology and morphology: collar, ligule, (open) sheath, auricle !21 ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona Grass morphology: leaves Grass-specific morphology: epidermis of long and short cells silica phytoliths (“grit”) !22 ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona Grass morphology: flowers general floral morphology: !23 ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona Grass morphology: flowers general floral morphology: inflorescence axis bract !24 ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona Grass morphology: flowers general monocot floral morphology: 6 tepals (sepals look like petals) 6 stamens 3 carpels, fused !25 ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona Grass morphology: flowers grass inflorescences: one or more spikelets: base: 2 bracts == glumes next: fertile florets some: sterile terminal floret !26 ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona Grass morphology: flowers grass flowers (florets): tepals: 2 => lodicules stamens: 3, sagittate carpels: 2, fused, feathery stigmas PLUS: lemma and palea !27 ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona Grass morphology: flowers grass flowers (florets): 2 tepals (~invisible)* 3 stamens typical monocot flower: 2 carpels 6 tepals PLUS: lemma and palea 6 stamens 3 carpels grass plant flowers are highly modified! !28 ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona Grass morphology: flowers gene expression and other data support: palea and lemma are tepals. !29 ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona Grass morphology: flowers gene expression and other data support: palea and lemma are tepals. standard monocot !30 ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona Grass morphology: fruits Grain: a grass-specific fruit type two fused carpels fruit indehiscent, wall fused to seed (bran) usually dispersed with palea, lemma (chaff) embryo small (germ) !31 ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona Good luck! !32 Muhlenbergia mexicana, Paul Rothrock ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona.