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?