Winter Twig Identification Class

Winter TwigIdentification Class

Goals of class:

1. Gain necessary vocabulary2. Learn some “reference species”3. Improve growing season skills4. Change attitudes concerninglength of field season

Node

Internode

Features of the node

leaf scar

leaf scarbundlescar

leafscarbundle

scars

leaf scar encircles bud

stipules

stipulescars

leafscar

stipulevestiges

winterbuds

lateralwinterbuds

terminalwinterbuds

no terminal bud

terminalwinterbud

DETERMINATE TWIG

terminalbud stopsgrowth

leaf scars

DETERMINATE TWIG

winter twig

pseudoterminalwinterbud

leafscar

twigscar

INDETERMINATE TWIG

directionof growth

apicaltwiggrowth

leaf scars

twig scar

leaf scars

INDETERMINATE TWIG

winter twig

stalkedwinter bud

sessilewinter bud

buds scales

imbricate buds scales

valvate buds scales

single buds scale

naked bud

superposedbud

collateralbuds

Features of the internode

pith

solid pith

chambered pith

diaphragmmed pith

triangular pith

stellate pith

Lenticels

pubescent twig

glaucoustwig

(pruinose)

scaly twig

stipitate-glandulartwig

Armature

armature(prickles)

armature(spines)

armature(thorns)

Phyllotaxis

Phyllotaxis is a description of how nodes are arranged on a stem and is expressed as a fraction.

1/3The numerator represents the number of revolutions around the stem to return to a node of similar position.

The denominator represents the number of nodes that must be counted to return to a node of similar position.

Miscellaneous

short shoots

deciduousleaves

marcescentleaves

evergreen leaves

preformed staminateaments

preformed staminateaments

fruits

fallenfruits

bark

fallen leaves