Tree Identification and Pennsylvania Species Flashcards

Exactly 60 vocabulary flashcards covering tree identification terminology, anatomical parts, and common Pennsylvania species based on lecture notes.

Deciduous

A plant that sheds its leaves seasonally, usually in fall or winter.

Evergreen

A plant that retains its foliage year-round, replacing leaves gradually rather than all at once.

Needle-like leaves

Narrow, individual needle-shaped foliage, typical of many conifers like pines and spruces.

Scale-like leaves

Foliage consisting of tiny overlapping scales, often arranged in flat sprays, as seen in Arborvitae.

Simple leaf

A leaf consisting of one continuous blade, regardless of whether it is lobed or has deep sections.

Compound leaf

A single leaf that is divided into multiple leaflets attached along a central stalk or point.

Rachis

The single central stalk of a compound leaf to which multiple leaflets are attached.

Opposite branching

An arrangement where two leaves or twigs emerge from a branch directly across from one another.

Alternate branching

An arrangement where leaves or twigs emerge one at a time, alternating along the stem.

Whorled arrangement

A structure where three or more leaves attach at the same point along the stem.

Petiole

The leaf stalk that attaches the blade to the twig.

Axillary bud

The bud at the junction of the twig and petiole; its presence identifies a true leaf versus a leaflet.

Pinnately compound

A compound leaf with leaflets arranged on opposite sides of an elongated axis.

Palmately compound

A compound leaf where leaflets all attach near a common point, resembling the fingers of a hand.

Serrate margin

A leaf edge featuring sharp, forward-directed teeth.

Double serrate margin

A leaf edge where each sharp, forward-directed tooth bears even smaller teeth.

Dentate margin

A leaf edge with sharp teeth that point directly outward.

Lobed margin

A leaf edge with relatively large, rounded projections, resembling ear lobes.

Entire margin

A leaf edge that is smooth and lacks teeth or lobes.

Samara

A type of fruit consisting of a winged seed, typically found on Maples and Ashes.

MAD Horse

A memory phrase for trees with opposite branching: Maple, Ash, Dogwood, and Horsechestnut (or Buckeye).

Eastern White Pine (Pinus strobus)

A conifer with soft, flexible needles arranged in bundles of $5$.

Virginia Pine (Pinus virginiana)

A conifer with twisted, stout needles in bundles of $2$, typically a southern species reaching its northern limit in Pennsylvania.

Pitch Pine (Pinus rigida)

A fire-adapted conifer with stiff needles in bundles of $3$ and resinous wood used for railroad ties.

Eastern Hemlock (Tsuga canadensis)

The official state tree of Pennsylvania, featuring short, flat individual needles with two pale white lines underneath.

Eastern Red Cedar (Juniperus virginiana)

A conifer with mature scale-like foliage and bluish, berry-like cones.

Eastern Arborvitae (Thuja occidentalis)

Also called Northern White-cedar, it features flat, fan-shaped sprays of scale-like foliage.

American Holly (Ilex opaca)

A broadleaf evergreen with stiff, leathery leaves featuring sharp spines and bright red berries on female trees.

Norway Spruce (Picea abies)

An introduced species with sharp individual needles and large, cylindrical cones $5$ to $7\,inches$ long.

Red Maple (Acer rubrum)

A tree with opposite, simple leaves with $3$ to $5$ shallow lobes and red twigs.

Sugar Maple (Acer saccharum)

An important timber tree with opposite simple leaves featuring $5$ lobes and U-shaped sinuses.

Norway Maple (Acer platanoides)

An introduced ornamental with opposite leaves that exude a milky white sap from the petiole when detached.

Northern Red Oak (Quercus rubra)

A dominant forest tree with alternate, simple leaves having $7$ to $11$ bristle-tipped lobes.

White Oak (Quercus alba)

A long-lived tree with alternate, simple leaves featuring $6$ to $10$ rounded lobes without bristles.

Chestnut Oak (Quercus montana)

A tree of dry ridgetops with large, egg-shaped acorns and leaves with $7$ to $16$ pairs of rounded teeth.

American Beech (Fagus grandifolia)

A tree known for its smooth, light gray bark and simple, alternate, sharply-toothed leaves.

Yellow Birch (Betula alleghaniensis)

A tree with yellowish or bronze shiny bark that peels in papery strips and smells of wintergreen.

Sweet Birch (Betula lenta)

Also called Black Birch, it has dark reddish-brown bark and twigs with a strong wintergreen flavor.

Paper Birch (Betula papyrifera)

A tree with chalky white bark that peels in thin layers, historically used for canoes.

Black Cherry (Prunus serotina)

A valuable hardwood with simple alternate leaves possessing small, in-curved teeth at the margins.

American Elm (Ulmus americana)

A large shade tree with a vase-shaped silhouette and alternate simple leaves that are unequal at the base.

Bitternut Hickory (Carya cordiformis)

A tree with alternate compound leaves ($7$ to $11$ leaflets) and distinctive sulfur-yellow buds.

Shagbark Hickory (Carya ovata)

A tree recognized by its gray bark that peels into long, shaggy plates and leaves with $5$ leaflets.

Black Walnut (Juglans nigra)

A tree with alternate compound leaves ($15$ to $23$ leaflets) and a pale brown chambered pith.

Butternut (Juglans cinerea)

Also called White Walnut, it has compound leaves with a sticky main leaf-stem and chocolate-brown chambered pith.

Tulip-poplar (Liriodendron tulipifera)

The tallest eastern hardwood, featuring alternate simple leaves with a squared-off and broadly notched tip.

Sassafras (Sassafras albidum)

A tree with aromatic leaves that can be entire, two-lobed, or three-lobed on the same tree.

Sycamore (Platanus occidentalis)

A massive tree with peeling outer bark and alternate leaves with a hollow petiole base that encloses next year's bud.

Sweetgum (Liquidambar styraciflua)

A tree with star-shaped leaves showing $5$ to $7$ pointed lobes and resinous fragrance when crushed.

Black Locust (Robinia pseudoacacia)

A medium-sized tree with alternate compound leaves and twigs featuring pairs of short, stout spines.

Medullary rays

Tree structures that conduct food and water radially and serve in food storage.

Cambium

The growing layer of a tree where cells divide to form both bark and wood.

Sapwood

The active layer of a tree's wood that carries food and water upward.

Heartwood

The inactive, central cells of a tree that provide structural support.

Inner bark

The part of the tree that carries food manufactured in the leaves downward to the cambium.

Outer bark

The protective outer layer of inactive cells that guards the inner bark.

Annual rings

Markings indicating the tree's growth, normally representing one ring per year.

Lenticel

A pore in the bark of young branches and trunks that allows for gas exchange.

Flowering Dogwood (Cornus florida)

A small tree with prominent curved leaf veins and conspicuous, silvery, button-shaped flower buds.

American Larch (Larix laricina)

The only native Pennsylvania conifer that turns yellow and drops its needles annually in autumn.