Introduction to Grasses Candice Prince, UF/IFAS Center for Aquatic and Invasive Plants Graminoids = “grass like” plants 1. Grasses (Poaceae) 2. Sedges (Juncaceae) 3. Rushes (Cyperaceae) Graminoids = “grass like” plants 1. Grasses (Poaceae) 2. Sedges (Juncaceae) 3. Rushes (Cyperaceae) Sedges have edges, rushes are round, grasses have joints all the way to the ground Sedges Rushes Grasses • Triangular stems • Round stems • Round to ellipsoid • Nodes not jointed • Nodes not jointed • Nodes are jointed • Solid stems (not hollow) • Solid stems (not hollow) • Stems usually hollow Images: Hilton Pond Center Sedges Rushes Grasses Illinois Wildflowers • 3-ranked leaves • 3-ranked leaves • 2-ranked leaves • Leaves flat or channeled, • Leaves round, reduced, or flat • Leaves flat, channeled, or round sometimes reduced Sedges Rushes Grasses Max Licher • Inflorescence subtended • Inflorescence subtended by bracts • Inflorescence not subtended by bracts by bracts (usually prominent) (not prominent) Sedges Rushes Grasses Backyard Nature • Achenes (single seeded hard • Many-seeded capsule • Caryopsis (grain) fruit) Florida Grasses • ~450 species in FL • Found in every community type, wide range of conditions • Fire • Wetlands/flooding • Brackish conditions • Xeric conditions Graves Lovell, Bugwood.org Forest and Kim Starr, Bugwood.org Kaitlyn Quincy, UF/IFAS How to Identify Grasses? Questions to ask: •What is the overall appearance? What is the overall appearance? •Is it a bunch (caespitose) or creeping grass? Rebekah D. Wallace, Bugwood.org Jeff D. Hansen What is the overall appearance? •If creeping: rhizomes, stolons, both? What is the overall appearance? •Height? Color? Kevin Hudson, MSU Ag Communications Walters Gardens What is the overall appearance? •What are the culms (stems) like? • Color? Node Internode • Smooth? Ribbed? • Hairy nodes? Node Questions to ask: •What is the overall appearance? •What are the leaves and sheath like? What are the leaves and sheaths like? •What is the texture? Blade •Smooth? (Lamina) •Hairy? Midrib •Waxy? •Are the margins sharp? Margin •Are the veins or midrib prominent? •Are the leaves flat? V-shaped? Chris Evans, Bugwood.org What are the leaves and sheaths like? •What is the texture? •Smooth? •Hairy? •Waxy? •Are the margins sharp? •Are the veins or midrib prominent? •Are the leaves flat? V-shaped? University of Nebraska-Lincoln What are the leaves and sheaths like? Blade Midrib Margin Arthur Haines Penn State Extension Questions to ask: •What is the overall appearance? •What are the leaves and sheath like? •What is the collar region like? What is the collar region like? Iowa State University Oregon State University What is the collar region like? Penn State Extension Oregon State University What is the collar region like? •Does it have a ligule? •Size of the ligule? •Is the ligule a membrane? Hairy? Oregon State University Peter Smith •Does it have auricles? Penn State Extension NC State Extension Amy Ferriter, Bugwood.org Questions to ask: •What is the overall appearance? •What are the leaves and sheath like? •What is the collar region like? •What type of inflorescence or seed head (if present)? Grass Inflorescence • Floret = grass flowers • Spikelet = one to several florets • Basic unit of inflorescence Aelwyn Image: E-Monocot Grass Inflorescence • Each spikelet held in pair of glumes • Glumes may or may not have awns (bristles) Aelwyn Grass Inflorescence • Floret: stamen and pistil enclosed by two bracts (lemma and palea) • May or may not have awns • May or may not have hairs • Pay attention to color Image: John K. Saichuk, LSU Image: E-Monocot What type of inflorescence? • Spike, raceme, or panicle? EM Armstrong What type of inflorescence? • Spike: unbranched, sessile (spikelets attached directly, no stalks) EM Armstrong What type of inflorescence? • Raceme: unbranched, spikelets attached by pedicels (stalks) EM Armstrong What type of inflorescence? • Panicle: branched, spikelets on pedicels EM Armstrong What type of inflorescence? • Some panicles are compact, appear spike-like Recap (Poll Question) • A branched inflorescence with spikelets on pedicels (stalks) is called what? • A: panicle • B: spike • C: ligule • D: auricles Recap (Poll Question) • A branched inflorescence with spikelets on pedicels (stalks) is called what? • A: panicle • B: spike • C: ligule • D: auricles Species Identification Wetland Grasses • Panicum repens (torpedograss) – exotic • Hymenachne amplexicaulis (West Indian marshgrass) – exotic • Urochloa mutica (paragrass) – exotic • Panicum hemitomon (maidencane) – native Panicum repens (torpedograss) Forest and Kim Starr, Bugwood.org P. repens – overall appearance • Spreads via rhizomes and stolons • Up to 3 ft. in height Rebekah D. Wallace, Bugwood.org • Hollow stems • Blue-grey color Ann Murray, Bugwood.org Forest and Kim Starr, Bugwood.org P. repens – leaves, sheaths, ligule •Stiff and folded •Leaves and sheaths hairy •Ligule hairy John D. Byrd, Bugwood.org P. repens – inflorescence •Loose, open panicle Ann Murray, Bugwood.org Harry Rose Hymenachne amplexicaulis – West Indian Marshgrass Far North Coast City Council H. amplexicaulis - overall appearance • Spreads via stolons and seeds • 3-8 ft. in height • Stems filled with white pith H. amplexicaulis – leaves, sheath, ligule • Hairs near base • Ligule a small membrane • Auricles wrap around culm Far North Coast City Council H. amplexicaulis - inflorescence • Spike-like panicle Urochloa mutica (paragrass) U. mutica - overall appearance • Spreads via stolons (seed germination low) Rebekah D. Wallace, Bugwood.org • 3 ft. in height Sheldon Navie • Hollow stems • Swollen hairy nodes Ann Murray, Bugwood.org Forest and Kim Starr, Bugwood.org U. mutica - leaves, sheath, ligule • Short hairs on leaves and sheaths • Ligule is a hairy membrane Rebekah D. Wallace, Bugwood.org Harry Rose Sheldon Navie Forest and Kim Starr, Bugwood.org U. mutca - inflorescence • Pyramidal panicle • Often purple-tinged Panicum hemitomon (maidencane) P. hemitomon – overall appearance •Rhizomatous •Hollow culms •May lean and root at nodes P. hemitomon – leaves, sheath, ligule •Leaves and sheaths smooth to sparsely hairy •Ligule is ciliate Southeastern Flora Larry Allain, US Geological Survey Larry Allain, US Geological Survey Larry Allain, US Geological Survey P. hemitomon – inflorescence •Spike-like panicle Cane Grasses – tall, with cane-like stems Jennifer Possley James H. Miller, Leslie J. Mehrhoff, Bugwood.org Bugwood.org Cane grasses • Phragmites australis (common reed) – native and exotic forms • Arundo donax (giant reed) – exotic • Neyraudia reynaudiana (Burma reed) – exotic Phragmites australis (common reed) P. australis – overall appearance • Up to 20 ft. tall • Spreads through rhizomes, stolons, and seeds P. australis – leaves, sheath, ligule • Leaves have sharp margins • Ligule is a fringe of hairs Larry Allain, US Geological Survey P. australis – inflorescence Joseph DiTomaso, Bugwood.org • Large panicle • Awns on upper florets • Silky hairs at maturity Minnesota Wildflowers Phragmites haplotypes Eurasian Haplotype Gulf Coast Haplotype Inflorescence Compact, erect Open, drooping Stem Ribbed Smooth Height 6.5 to 13 ft. Up to 20 ft. Arundo donax (giant reed) A. donax – overall appearance • To 20 ft. tall • Forms clumps • Spreads via rhizomes, stem fragments Joseph M. DiTomaso, Bugwood.org John Ruter, Bugwood.org A. donax – leaves, sheath, ligule • Light brown collar and auricle Amy Ferriter, Bugwood.org • Sharp margins • Hairy ligule Harry Rose Larry Allain, US Geological Survey A. donax – inflorescence Rebekah D. Wallace, Bugwood.org • Plume-like, compact panicle • Upright • Spikelets have awns Jim Conrad Burma Reed (Neyraudia reynaudiana) GlobalSpecies.org Overall Appearance •Spreads via wind-dispersed seeds and rhizomes •Clumping, to 10 ft. in height •Stems are filled with pith, often branched Dan Clark, Bugwood.org Leaves •Blades to 39 in. long, hairy on top •Ligule and collar have hairs Inflorescence •Large panicles (to 24 in. in length) •Feathery appearance •Silver hairs Dan Clark, Bugwood.org Upland Grasses • Imperata cylindrica (cogongrass) – exotic • Melinis repens (natal grass) – exotic Cogongrass (Imperata cylindrica) Photo: Chris Evans, Bugwood.org Photo: Chris Evans, Bugwood.org Overall Appearance • Spreads via rhizomes and seeds • May reach 6+ ft. • No aboveground stems, leaves arise directly from rhizomes Chris Evans, Bugwood.org Overall Appearance •Rhizomes: •Scales •Sharp-pointed tips Rebekah D. Wallace, Bugwood.org Chris Evans, Bugwood.org Leaves Chris Evans, Bugwood.org •Off-center white midrib •May be hairy at base •Rough edges Leaves Chris Evans, Bugwood.org •Sheaths are short •Ligule is a fringed membrane Inflorescence •Dense panicle •White/silver •Plume-like •Up to 8 in. long Chris Evans, Bugwood.org Chris Evans, Bugwood.org Julia Scher, Bugwood.org Natal Grass (Melinis repens) Overall Appearance •Spreads via seed •Grows in clumps to 4 ft. in height •Bunch grass Leaves • To 1 ft. in length, upper surface slightly rough • Sheaths glabrous, may have long hairs • Ligule: short hairs Inflorescence • Panicle, to 8 inches long • Pink to purple, hairs turn silver with maturity • Spikelets with long hairs Forest and Kim Starr, Bugwood.org Thank you! Candice Prince [email protected].