Transcript Forms of Inflorescence: panicle, raceme, spike

How to identify prairie plants?
• 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
Dicotyledon class:
two seed leaves
netted veins
tap roots
floral parts mostly in
4’s and 5’s
Monocotyledon Class:
one seed leaf
parallel veins
horizontal rootstalks
floral parts mostly in 3’s
IF A MONOCOT
• 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.
IF A DICOT
• 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
Composites - Asteraceae
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
Groupings in Dicot Flowers
• 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.
More Dicots
Gromwell Lithospermum
Rose
Harebell
Filago
Morning glory - Convolvulus
Mustard
SAGES
Asteraceae
Artemisia
frigida
Artemisia
ludoviciana
Artemisia dracunculus
Using keys to plants
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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 3-6’ 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”
On to grasses …
• 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
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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
• 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
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
Panicle – pedicel –
Poa pratensis
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 Tritice
– spikelets are sessile on central ax
SPIKE - Elymus smithii – Western wheat grass
SPIKE - Great Basin Wild Rye – taller grass
Raceme – spikelets on pedicels
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