GRASSES Graminoid Learning Curve GRASSES
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GRASSES Graminoid Learning Curve GRASSES • 446 species • 120 Genera • 9 larger genera: • Aristida (22) • Andropogon (18) • Dichanthelium (24) • Digitaria (20) • Eragrostris (29) • Panicum (16) • Paspalum (30) • Setaria (15) • Urochloa (14) • Many widespread species distributed across most habitats • Key Characters: • Stems have joints • Leaves 2-ranked • Stems hollow • Sheaths open Grass Morphology. 1. Vegetative features: 2. Caryopsis (grain). 3-6. Spikelets: 3. Spikelet with many florets. 5. 4. Spikelet with 2 florets (dorsally compressed); 5. Spikelet with one floret (laterally compressed); 6. Spikelet with 2 florets (Andropogon); 7. Rhizomes Practical Grass Identification • Takes a little TLC oTerminology oLearning Network oCollections “So the lower and larger of the two modified bracts- you know, the modified leaves or Terminology scales- that directly surround the individual occurrences of sexual organs within the larger • Grasses have unique flowering structure of a grass- structures that require you know, a plant in the family specific terminology or Poaceae… man, I wish there jargon in order to discuss was a word for that…” them Lemma, Derek. Lemma. (rolls eyes) Were you not at the CISMA workshop?L • Do not fear! • Actually a form of shorthand • Effective communication, not esoteric elitism! Learning Network • Internal (silent) network • Books, websites, etc • Tools • Personal collection of specimens/photographs • Notes! • External (audible) network • Peers, colleagues, CISMA! • Experts • Herbaria • Online forums • EDDMaps ISB Atlas of Florida Plants So much info!!! USF specimens • Good for scale • Locality info, date, etc. • Contact collector • Ctrl+f is your friend plants.usda.gov/plantkeys Other websites • Floridagrasses.org • herbarium.usu.edu/webmanual/default.htm • North America (under construction) • BONAP.org Books • Guide to the Vascular Plants of Florida • Wunderlin & Hansen • Grasses of the United States • Hitchcock • A Guide to Florida Grasses • Taylor • Aquatic and Wetland Plants of the Southeastern United States • Godfrey & Wooten • Manual of Grasses for North America • Barkworth et al. Collections • Collect ENTIRE, MATURE plant(s), trowel helps • Checklist • Photo • Name • Date • Location info • County, Site • Habitat • Standing water, etc • other species (sympatrics) • GPS • Basic description (pre-press) • Habit • Color • Permit/Permission • Share! • ID non-essential! Collections • Collect in Ziploc bags or even trash bags if you don’t have a press • Press in non-acid paper • Newspaper is perfect • 29x 42 cm • Herbariumsupply.com • Show everything you can! • Spikelets, undersides, roots, rhizomes, etc “So the lower and larger of the two modified bracts- you know, the modified leaves or Terminology scales- that directly surround the individual occurrences of sexual organs within the larger • Grasses have unique flowering structure of a grass- structures that require you know, a plant in the family specific terminology or Poaceae… man, I wish there jargon in order to discuss was a word for that…” them Lemma, Derek. Lemma. (rolls eyes) Were you not at the CISMA workshop?L • Do not fear! • Actually a form of shorthand • Effective communication, not esoteric elitism! Terminology Descriptive Taxonomic • Habit (growth form) • Tribes • Leaf structures • Genera • Inflorescence (tricky!) • Species Habit • Caespitose • Rhizomatous • Stoloniferous • Not always obvious • Muhlenbergia (Muhly) forms large, often dense colonies, but caespitose • Tripsacum (Fakahatchee) forms solitary clumps but with rhizomes • Collect ENTIRE plant! • Look for a line drawing Caespitose • Mature plants forming a solitary clump • Check for signs of (developing) rhizomes/stolons Rhizomatous • Clonal plant connected by underground stems (rhizomes) • Bamboos classic example • Variable • Short, long • Thick, thin • Smooth, scaly • Compare torpedograss (Panicum repens) to Johnsongrass (Sorghastrum halepense) • Look for Panicum anceps today! Stoloniferous • Clonal with aboveground runners, aka stolons • Look for D. longiflora on trails today… Other… • Height • Erect, decumbent, etc • Color • Leaf arrangement, angle etc Internode Joint (Node) Blade (parallel venation) Ligule / Collar Sheath Leaf structure • Terete (round) uncommon • Involute (inrolled) • Keeled • Flat Ligules can be variable • Hairs • Membrane • Both • Absent Review Review http://floridagrasses.org Grasses are flowering plants?!! Petals reduced to lodicules. Still serve a Stigma function! Style Anther Ovary Filament Lodicule The Grass Plant – the inflorescence • The inflorescence is the flowering part of a plant. • It varies a lot! Spike Raceme Panicle Stalked Branches Racing Peanut Stripes Butter Panicles highly variable! Branches sometimes hard to see Panicle My tricks • Glumes • It’s “glumey” at the bottom • Lemma • (L)emma is (L)ower and (L)arger. “Lemma looka that” • Palea • (P)alea is (P)etite and (P)artially (P)rotected. “Don’t palea no mind” Spikelets have 1-many flowers • 1 floret • Aristida • Rices (wetlands, sharp) • Leersia • Zizaniopsis • Zizania • Luziola • Sporobolus • Muhlenbergia Spikelets have 1-many flowers Many of ours have 2 Spikelets can be compressed in multiple ways Not compressed Laterally compressed Dorsally compressed Awns • Variable • Can be 1- several • From multiple bracts Review Aristida • Single, thin floret • Glumes • “Three awns” • You may run into wiregrass (Aristida stricta) outside. Look for tuft of hairs at base of leaf Andropogon • Distinctive, typically tall • Difficult to ID to species! • Clumping • 2 rows of bearded, paired, awned spikelets • Leaf bases typically flat Andropogon Spathe Callus trichomes Post-flowering peduncle Paspalum • Short-stalked racemes • Distinctive spikelets • 2-flowered spikelets • “Footballs in cross section, flatside out” • Look for Paspalum notatum, P. conjugatum, and P. setaceum • Many exotics, esp in SFL Panicum • Historically large group with many taxonomic issues • Panicles • 2-flowered spikelets • One fertile, one male or sterile • Fertile lemmas shiny and smooth Urochloa maxima • Compare with rugose (wrinkled) lemma of guineagrass (formerly Panicum maximum) • FLEPPC Cat II Dichanthelium • Witchgrasses • Small Panicums • 2 florets • Extremely difficult to ID • Often with two distinct forms (spring, fall) • One erect, one rosette • Look for D. aciculare and D. commutatum Digitaria • Crabgrasses • Often weedy • Many stoloniferous • 2-flowered spikelets • Dorsally compressed Eragrostis • Lovegrasses • Compound spikelets (multiple florets) • Laterally compressed • Diffusely branched • Lemma apex not awned Setaria • Foxtails • Bristles beneath, not awns • Spikelets round unlike Pennisetum Review Review Questions?.