FIELD BOTANY – Lecture 02Dr. Donald P. Althoff

LEC 02

AngiospermsEvolutionary TrendsClassification Notes

Evolutionary Trends in Angiosperms (in general)

• Woody plants usually _________ the herbs, vines, and climbers

• ______________ gave rise to biennials…and annuals have derived from both perennials & biennials

• Dicots are considered ______ primitive than monocots

Seed-bearing

Flowers

gymnosperms DICOTS

Evolutionary Trends in Angiosperms (in general)…con’t

• Alternate leaves with secretory cells are ____________ compared to opposite or whorled leaves without secretory cells.

• Many separate stamens are more _________ than few or united stamens

• Single fruits _________ aggregate fruits formed from several ovaries

• OVERALL: _________ are not necessarily primitive, but have become _______ as a result of reduction from complex parts.

_______ Fruits __________ Fruits

St. Johnswort Fuschia

_______ Stamens _____ Stamens

Within the Division of Magnoliophyta ( = Anthophyta)

Two Classes*

• Dicotyledons (dicots): _______________

• Monocotyledons (monocots) __________

_______…in general (vs. monocots)

• ______ diverse • About _____ of species are ________• Cotyledons: __ (rarely 1, 3, or 4)• Leaves: usually __________• Primary vascular bundle: ________• Floral parts (except carpels) sets of _________• Root system: __________________

Abundance of ______________ roots

1 vs. 2 cotyledons

_________…in general (vs. dicots)• _____ diverse • Less than ____ of species are _______• Cotyledons: ___• Leaves: usually _________-veined• Primary vascular bundle: ________ or in 2 or more

______• Floral parts (except carpels) sets of _________• Root system: adventitious (characteristic of ferns, too)• Probably evolved from ___________ of dicots early in

the evolutionary history of angiosperms

• Aceraceae • Anacardiaceae • Annonaceae • Betulaceae • Caprifoliaceae • Cornaceae • Ericaceae • Fagaceae • Grossulariaceae

Woody (tree/shrub/vine) Families

• Hippocastanaceae • Juglandaceae • Magnoliaceae • Moraceae • Oleaceae • Salicaceae • Smilacaceae • Ulmaceae

Some…

• Guttiferae (Clusiaceae)• Lamiaceae • Liliaceae • Lythraceae • Malvaceae • Nymphaeaceae • Orchidaceae • Oxalidaceae • Phytolaccaceae • Polygonaceae • Portulacaceae • Ranunculaceae • Scrophulariaceae

• Alismataceae • Apiaceae • Apocynaceae • Araceae • Asclepiadaceae • Asteraceae • Balsaminaceae • Brassicaceae • Campanulaceae • Caryophyllaceae • Convolvulaceae • Fabaceae***• Geraniaceae

Forb/Herb FamiliesSome…

“Combo” Families: woody & herb• Fabaceae [alternate name: Leguminosae]

“legumes family” alfalfabirdfoot treefoil partridge pea round-headed

lespedeza s. partridge pea slimflower scurfpea white clover yellow sweet clover wild blue indigo black locust*

• Rosaceae “rose family”rough avens* white avens* Am. plumblack cherry black chokeberry

black raspberry blackberry prairie rosemulti-flora rose sweet (American) crap apple

DIC

OT

DIC

OT

Kingdom Division Class

Subclass Order

Family Genus

PlantaeMagnoliophyta (Anthrophyta)

Magnoliopsida-dicots

Liliopsida-moncots

-6 -5

1

2

1 2

Dicotyledons (Division Magnoliophyta,

Class Magnoliopsida)

• Advancement• Carpels• Flowers• Stamens• Pollen

Characteristics Subclasses (6)

Cronquist system 1981

1

• Magnoliidae (8o.39f.11,000s) • Hamamelidae (11o.24f.3,400s)• Caryophyllidae (3o.14f.11,000s)• Dilleniidae (13o.78f.25,000s)• Rosidae (18o.114f.58,000s)• Asteridae (11o.49f.56,000s)

Monocotyledons (Division Magnoliophyta,

Class Magnoliopsida)

• Advancement• Carpels• Flowers• Stomatal

Subsidiary Cells

Characteristics Subclasses (5)

2

• Alismatidae (4o.16f,500s)• Arecidae (4o.5f.5,600s)• Commelinidae

(6o.16f,16,200s)• Zingiberidae (2o.9f.3,800s)• Liliidae (2o.19f,25,000s)

Characteristics helpful in “subclass” classification

• ________________: 1 or more features vs. relatively primitive

• Carpels: apocarpous vs. syncarpous• Flowers: primitive to well developed• Pollen: monosulcate vs. tricolpate

(for dicots)• Stomatal subsidiary cells: 04 (for monocots)

• CARPELS = megasporophyll

APOCARPOUSCarpels _________ in single individual pistils

SYNCARPOUS_______ Carpels resulting

in compound ovary

• POLLEN___________________

boat-shaped, 1 long germinal furrow,

___ germinal aperture

_________________globosesymmetrical, usually ___ germinal

apertures

onion

oak

grass

Lilium

Artemisia

• STOMATAL SUBSIDIARY CELLS: 04 (for monocots)

Summary thoughts on classification…for now

• ______ characteristics to examine• Some characteristics are very “definitive”…

others require some “_______________” (ex. primitive vs. slightly advanced)

• _______________ into a subclass, order, family, and even genus is subject to revision