Beginning Grass Identification Workshop

Mike Bauer July 2018

University of Arizona Herbarium Arizona Native Plant Society

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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

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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)

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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

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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

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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)

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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, ...

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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

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ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona Grass relatives

Grasses are Monocots

Magnoliids Eudicots

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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

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ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona Grass morphology: architecture

grass plant body

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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

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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

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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”)

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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

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ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona Grass morphology: leaves

monocots non-monocots

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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

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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

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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”)

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ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona Grass morphology: flowers

general floral morphology:

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ARIZ-NPS Grass Workshop, July 2018 Michelle McMahon, School of Plant Sciences, University of Arizona Grass morphology: flowers

general floral morphology:

inflorescence axis

bract

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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

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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

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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

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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!

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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.

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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

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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)

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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