Forest Biology Fall 2025 Clemson University

Entire

What kind of leaf margin is this?

Serrate

What kind of leaf margin is this?

Doubly Serrate

What kind of leaf margin is this?

Dentate

What kind of leaf margin is this?

Crenate

What kind of leaf margin is this?

Polymorphism

What is the term for when a tree displays multiple leaf shapes?

Pinnate

What type of venation is this?

Palmate

What kind of venation is this?

Glabrous

What surface leaf texture is smooth?

Pubescent

What surface leaf texture is soft with fine hair (pubescence)?

Tomentose

What surface leaf texture is matted with woolly hair (tomentum)?

Scabrous

What surface leaf texture is sandpaper-like?

Glaucous

What surface leaf texture has a white waxy surface (common on the undersides)?

Rugose

What surface leaf texture has sunken veins?

Scaly

What surface leaf texture has scales that falls of easy when rubbed with a finger?

Coriaceous

What surface leaf texture is thick and leathery, common in evergreens?

Papery

What surface leaf texture is thin, membranous, and deciduous?

Long petiole

What kind of petiole do maples have?

Short petiole

What kind of petiole do oaks have?

Sessile petiole

What kind of petiole do crapemyrtles have?

Hollow

What is the term for a petiole that encloses the bud (enclosed bud)?

Glandular

Term for trees (Black Cherry) that have glands on top of petiole before base of the leaf?

Stipule

A leaf appendage attached to the petiole or twig near the base of the petiole

Pines (Pinus)

Produce evergreen needles in bundles (fascicles)

Spruces, Firs, Hemlocks, Douglas-firs, Cedars, and Larch

Produce individual evergreen needles

Awl-shaped foliage

Short, triangular in cross-section, and sharply pointed foliage that is rigidly attached; common in "cedars"

Scale-like foliage

Small, thin, and usually flat "scales" that often have stomatiferous lines between them.

Branchlets

Featherlike and decidious foliage. Common in Bald cypress, Pond cypress, and Dawn redwood

Taxodium, Meta sequoia, Larix, and Ginkgo

What gymosperm trees are deciduous and not evergreen?

Twigs

What is the current year's growth of a branch called?

Bud

Term for future growth of a branch that is currently dormant?

Valvate

What kind of bud scale includes two non-overlapping scales?

Imbricate

What kind of bud scale includes overlapping scales, like shingles of a roof?

Cap-like

What kind of bud scale includes one single scale with conical shape?

Naked

What is the term for a bud that is unprotected by scales?

Pith

Spongy central tissue in twigs, young stems, and some roots

Starch Storage

What is the primary function of pith?

Leaf scar

Scar remaining after a leaf falls off of a twig

Bundle scars

Scar remaining on a twig, within the leaf scar, after the leaf falls. It is the severed ends of vascular tissue (xylem and phloem)

Stipular scars

For stipulate species, it is the scar left behind after the stipule falls off

Lenticels

Slightly raised, somewhat corky, pore sometimes visible on twigs and young stems. It enables gas exchange between the atmosphere and internal tissues

Primary

Type of growth for the shoot and root tips

Secondary

Type of growth in the diameter of the tree

Meristems

Where does growth occur?

Meristem

Undifferentiated, actively dividing tissues

Apical meristems

Plant tissues at the tips of roots and shoots that affects primary growth

Lateral meristems

Plant tissue in the cambium that affects secondary growth

Protoderm, Cork Cambium

The ____ arises from the apical meristem and becomes the _______, actively divides to produce bark

Procambium

What is inside of the protoderm that becomes the vascular cambium?

Xylem and Phloem

What does vascular cambium become (creates) when it divides?

Xylem

Which is closer to the center? Xylem or Phloem

Excurrent Growth

Prolonged main axis (bole/trunk) from which lateral branches arise

Decurrent Growth

Irregular growth pattern, typically without a clearly defined main axis

Fixed (determinate) growth

Type of growth defined by new stems and leaves forming in the bud, where tissues overwinter and expand/elongate in the following year. Resources stored for a short period of primary growth the following year

Determinate shoot growth pattern

The formation of a true, terminal bud and results in relatively straight twigs

Free (indeterminate) growth

Type of growth that is defined by new tissues being produced at the apical meristems throughout the growing season and growth only stops when growing conditions become unfavorable

Indeterminate shoot growth pattern

Twig elongation and bud formation continue until twig growth is stopped by short days or frost

Pseudoterminal bud

The last formed lateral bud that remains when indeterminate growth stops; acts as the terminal bud when growth begins as conditions become favorable

Recurrent Flushing (semi-determinate)

Free growth occurs when conditions are good; when conditions are bad, new stems/leaves are dveeloped, but remain dormant in the bud until it flushes when conditions are favorable

Bole

The main stem of a sapling or mature tree (jargon for trunk)

Wood

An organic compound comprised of cellulose fibers and lignin, mostly xylem

Sapwood

What is the term for active xylem cells

Xylem

Provides upward water and nutrient transport, strengthens the stem, and to some extent serves as a food storage reservoir

Vessel Elements (Angiosperm xylem)

Chief water-conducting tissues where end cell walls are absent, less resistance to water flow. Composed of single cells from which end walls have disintegrated and superimposed upon each other to create a tubular structure

Tracheids (Gymnosperm xylem)

Overlap and are arranged in radial rows. The walls have various types of pits that facilitate the transfer of materials between adjacent cells

Tranverse Elements (Angiosperms)

Wood rays comprise the major transversely oriented elements of wood, look like wheel spokes in a cross section. Plays a part in radial translocation of water, minerals, and organic materials

Upper

In hardwoods, tension wood is formed on the ____ side of leaning stems

Lower

In conifers, compression wood is formed on the ____ side of leaning stems

Roots

-Water uptake, mineral uptake

-Storage organ

-Anchorage

-Symbiotic relationship

-Soil stabilization

-Stored resources for next year's growth

Tap root system

What root system is common among trees?

Fibrous root system

What root system is common in monocots?

Adventitious root system

What root system is formed from other portions of the plant (not from root tissue)?

Radicle (Embryonic root)

What part of the seed do roots originate from?

Primary

_____ roots arise from the embryo radicle

Secondary

_____ roots branch off of the primary roots

Root Hairs

_____ are the extensions of the roots that assist with absorption of nutrients

Buttress roots

Certain species of trees produce ____ roots toward the base of the trunk, which provide considerabel stability

Mycotrophy

Nutrient uptake via mycorrhizae

Mycorrhizae

A symbiotic association of myxorrhizal fungi and roots of higher plants

-Plants provide carbohydrates

-Fungi enhance access to soil resources

Ectomycorrhizae

A type of mycorrhizae that occurs in pine, oaks, eucalyptus, and others. A thick hyphal mat (mantle) surrounds the root. Hyphae penetrate into the cortex and form a network ("Hartig net" around the cortical cells)

Arbuscular (aka endo-)

Type of mycorrhizae that occurs in herbaceous vegetation and some woody species. Tropical trees as well. Push into the cortical cells of roots. They produce characteristic Vesciles (storage) and arbuscules (highly branched structures). External hyphae can extend great distances from the root.

Nitrogen fixation

There is a symbiotic association between N2 fixing bacteria and the roots of some plants. The tree provides carbohydrates from photosynthesis; the fungus provides nitrogen.

Linear

What is this leaf shape?

Oval

What is this leaf shape?

Oblong

What is this leaf shape?

Ovate

What is this leaf shape?

Obovate

What is this leaf shape?

Deltoid

What is this leaf shape?

Cordate

What is this leaf shape?

Elliptical

What is this leaf shape?

Lanceolate

What is this leaf shape?

Phloem

Living tissue that transports the soluble organic compounds from photosynthesis.

Vascular Cambium

Where does phloem originate from?

Diffusion and Pressure

What two things are responsible for moving sugar in phloem?

Passive

Is sugar movement by diffusion and pressure active or passive transport?

Alive

Unlike xylem, phloem is ______.

True

Angiosperms have sieve tubes that are associated with one or more companion cells. True or False?

No

Do sieve tubes have a nucleus?

Companion cells

What provides the support to keep sieve tubes going?

Sieve Cells

Gymnosperms have trachied-like _____ that overlap.