HOME

Class
Schedule
(with links to lecture outlines)

Assignments

Labs

Species Gallery

Vocabulary

Key Features

ACERACEAE: Maple family

Genus Acer—Maple

Trees and large shrubs usually shade tolerant—good example of late successional tree geometry and life history traits (even though seeds are wind dispersed)

Genus key features:

fruit: double samara;
leaves: usually opposite, palmately lobed leaves

Species distinguished by:

• # lobes
• depth of sinuses
• shape of sinuses
• margins (entire versus serrate)
• angle between wings of samara

Acer circinatum
Acer macrophyllum
Acer saccharum

MAGNOLIACEAE-- Magnolia Family

Primitive Angiosperm family: most are from southeast Asia, thought to be location of evolution of Angiosperms. Many planted as ornamentals due to very large flowers. Mostly trees (some shrubs).

Family key features:

large terminal buds and flowers
circular stipular scars

Genera: Magnolia and Liriodendron

Magnolia grandiflora
Liriodendtron tulipifera

ROSACEAE-- Rose Family

very large family (3,000 species) with variable growth forms (herbs to trees), leaves (simple, compound), fruits (e.g., cherry, plum, apricot, nectarine, apple, strawberry, blackberry, raspberry)

Family diagnostics: variable, flowers generally with 5 unfused petals (similar to black berries)

Variety of fruit types from similar flowers:

• drupe (cherry)
• pome (apple)
• aggregate of drupelets (black berry)
• aggregate of achenes (strawberry)
• hip (rose)

Genera: Sorbus, Prunus (key features):

Genus	Leave	Fruit
Sorbus	variable (simple, pinnately compound	pome
Prunus	simple, extrafloral nectary	drupe

Sorbus aucuparia
Prunus emarginata

CORNACEAE-- Dogwood Family

(large family, family characteristics variable; not commercially important for timber)

Cornus-- most have opposite, leaves with arcuate venation, entire margins (all have latex in veins of leaf)

Shrubs and small trees- with several types of inflorescences
Our species have flowers in heads, subtended by white showy bracts

• Cornus nuttallii-- 2 flowering periods per year, 5-6 bracts without notch, smooth bark, twigs not glaucous
• Cornus florida-- 1 flowering period, 4 bracts with notch, rough (cornflake) bark, glaucous twigs

 

 

BACK TO
TOP