• Look at pictures of plants and use keys – dichotomous, polyclave, interactive – give some examples later.
• Pictures in books work best for plants with showy flowers. For grasses, keys are a must.
• How to decide if a plant is a grass or a forb? How to decide which key to use?
• Focus for this class is mostly grasses.

Which Key to Use
• First, to which division of the Plant Kingdom does the plant belong? This is based on how the plant reproduces .
– Spores – Lichen, Mosses & Liverworts, Ferns,
(Bryophyta, Pteridophyta)
– Naked seeds, ie conifers (Gymnospermophyta)
– Seeds enclosed in an ovary – flowering plants
(Angiospermophyta)
• Montana prairies do include some lichens and mosses, but not ferns (club moss, horsetail, royal fern), unlike UNDERC-East.

Prairie Plants = Flowering Plants
• Flowering plants include flowers, grasses, deciduous trees.
• What makes the distinction?
• Angiosperms are split into 2 classes of plants: those with one seed leaf or
Monocotyledoneae; those with 2 seed leaves or Dicotyledoneae.
• Is your plant a monocot or dicot?

Monocots vs Dicots
Monocotyledon Class: one seed leaf parallel veins horizontal rootstalks floral parts mostly in 3’s
Dicotyledon class: two seed leaves netted veins tap roots floral parts mostly in
4’s and 5’s

• Showy flowers?
– Examples – Lily family, Iris family, Orchid family
• Non-showy flowers?
– Examples – Grass, Sedge, Rush are only families appearing grasslike. Other aquatic families – cattail, pondweed, etc.

• Dicots account for many families with the Aster family as one of the largest.
– Aster family is the largest family of flowering plants in the northern latitudes – 346 genera and 2,687 species in US & Canada.
• Then, is your dicot plant a member of the Aster family?
– Most complex – “sepals” are bracts (ie artichokes), disk flowers and ray flowers
– Example – dandelion has only ray flowers

IF DICOT IS NOT ASTERACEAE
• If there is a flower - make notes on number of sepals, petals, and stamens.
Remember the order from outside to inside – Sepals, Petals, Stamens, Pistil in middle – flower parts occur in rings.
• Note whether flowers are regular or irregular
• Are sepals united or separate
• Notice position of leaves – ie alternate, opposite, basal or whorled

• Regular dicot flowers with numerous petals
– Cactus, bitterroot
• Irregular dicot flowers
– Teasel, Lupine/pea, butter & eggs/toadflax, penstemon, Bee balm/mint, Indian paintbrush
• Regular dicot flowers with 3 or 0 petals
– Spurge (eg poinsetta )
• Regular dicot flowers with 4 petals
– Phlox, plantain, harebell, dogwood, mustards
• Regular dicot flowers with 5 united petals
– Borage (Gromwell), morning glory
• Regular dicot flowers with 5 separate petals
– Rose, St Johnswort, Dianthus, Geranium

Some examples of prairie dicots:
Beebalm, Butter and eggs, yellowbell,
Indian paintbrush, Dianthus

Arrowleaf Balsamroot
Balsamorhiza sagittata
Bitterroot
Lewisia sp
Lupine Lupinus sp.

Harebell
Gromwell -
Lithospermum
Rose
Filago Morning glory Convolvulus
Mustard

SAGES
Asteraceae
Artemisia frigida
Artemisia dracunculus
Artemisia ludoviciana

• Variety of keys
• Some based on colors of flowers
• Some technical
• Regardless, important to keep in mind some basics – that is, keys help narrow down your choices by elimination
• For example, the following key to get to grasses versus forbs:

Variation in bracts around composite flowers

4 major North American graminoid plant families:
• Typhaceae - cattail (plants 36’ tall, flower spike
1” thick and 4-12” long)
• Juncaceae – rush (flowers not enclosed in chaff-like bracts) – “lilies turned to grass”
• Poaceae – grass (stems hollow, round; leaves wrapped around stem; leaves in 2 rows)
• Cyperaceae – sedge (stems solid, triangular; leaf bases forming tubes about the stem; leaves in 3 rows) – “sedges have edges”

• Agrostology = study of grasses
• Grasses are flowering plants, but the flowers lack showy petals and sepals seeds are wind-pollinated
• Grasses are in the family Poaceae
• Subdivided into 15 Tribes

15 major North American grass Tribes
• Triticeae : Agropyron , Elymus , Eremopyrum , Hordeum , Secale ,
Taeniatherum , and Triticum .
• Aveneae : Agrostis , Alopecurus , Avena , Beckmannia , Calamogrostis ,
Deschampsia , Helictotrichon , Hierochloe , Holcus , Koeleria , Phalaris ,
Phleum , Polypogon , Trisetum , and Ventenata .
• Stipeae : Stipa and Oryzopsis .
• Meliceae : Catabrosa , Glyceria , and Melica .
• *Poeae : Bromus , Dactylis , Festuca , Lolium , Poa , Puccinellia , and Vulpia .
• Andropogoneae : Andropogon , Sorghum , and Zea .
• Paniceae : Cenchrus , Dichanthelium , Digitaria , Echinochloa , Panicum ,
Paspalum , Pennisetum , and Setaria .
• Chlorideae : Bouteloua , Buchloe , Cynodon , Eleusine , Schedonnardus , and
Spartina .
• Aeluropodeae : Distichlis .
• Eragrosteae : Calamovilfa , Eragrostis , Muhlenbergia , Munroa , and
Sporobolus .
• Aristideae : Aristida .
• Arundineae : Arundo , Cortaderia , and Phragmites .
• Danthonieae : Danthonia .
• Oryzeae : Leersia , Oryza , and Zizania .
• Bambuseae : Arundinaria .

Grass Terminology –
Parts of a grass plant
• Leaf = sheath and blade joined by ligule
• Floret = flower is inside the:
– lemma (outer bract) and
– palea (inside bract)
• Spikelet = floret(s) along rachilla (central axis) and
– lower and upper glumes
• Forms of Inflorescence: panicle, raceme, spike

Grass Terminology –
Parts of a grass plant
• Floret = flower is inside the lemma (outer bract) and palea (inside bract)
• Spikelet = floret(s) along rachilla (central axis) and lower and upper glumes
• Forms of Inflorescence: panicle, raceme, spike

R. Pohl: How to Know the Grasses A. Chase: First Book of Grasses

Ligules (left and ctr)
Auricles (rt)

Grass Terminology –
Parts of a grass plant
• Leaf = sheath and blade joined by ligule
• Floret = flower is inside the lemma
(outer bract) and palea (inside bract)
• Spikelet = floret(s) along rachilla
(central axis) and lower and upper glumes
• Forms of Inflorescence: panicle, raceme, spike

Grass floret
Grass spikelet (generalized)

AWNS – protruding midrib of a lemma or glume; lateral nerves rarely produce awns
(Pohl 1954)
FLOWERS – stamens

Grass Terminology –
Parts of a grass plant
• Leaf = sheath and blade joined by ligule
• Floret = flower is inside the lemma (outer bract) and palea (inside bract)
• Spikelet = floret(s) along rachilla (central axis) and lower and upper glumes
• Forms of Inflorescence: panicle, raceme, spike

Forms of Inflorescence
Panicle
Raceme Spike

Poa pratensis
Panicle – pedicel – spikelets are not on main axis of inflorescence, but on branches
Festuca idahoensis

Grass showing panicle inflorescence, and the forb, Yarrow

Koeleria macrantha Bromus tectorum

Spike – most members of tribe Triticeae
– spikelets are sessile on central axis

SPIKE - Elymus smithii – Western wheat grass

SPIKE - Great Basin Wild Rye – taller grass

not a common arrangement
Crabgrass Digitaria

Festuca showing flowers
Avena – Oats showing awns
Lolium
Bromus japonicus http://gemini.oscs.montana.edu/~mlavin/herb/mtgrass.pdf

TOOLS for ID: KEYS and PICTURES
• "Grasses of Montana" by M. Lavin and C.
Seibert (2009). http://gemini.oscs.montana.edu/~mlavin/herb/mt grass.pdf
• National Plant Data Center – polyclave key http://npdc.usda.gov/technical/plantid_wetland_ mono.html