Trees of Eastern North America

721 Pages·2014·157.5 MB·English

by  Gil Nelson

Trees of
Eastern
North
America
Princeton Field Guides
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and provide detailed information on identification, distribution, and biology.
Birds of the Dominican Republic and Haiti, by Steven Latta, Christopher
Rimmer, Allan Keith, James Wiley, Herbert Raffaele, Kent McFarland, and
Eladio Fernandez
Birds of the West Indies, by Herbert Raffaele, James Wiley, Orlando Garrido,
Allan Keith, and Janis Raffaele
Caterpillars of Eastern North America: A Guide to Identification and Natural
History, by David L. Wagner
Common Mosses of the Northeast and Appalachians, by Karl B. McKnight,
Joseph Rohrer, Kirsten McKnight Ward, and Warren Perdrizet
Dragonflies and Damselflies of the East, by Dennis Paulson
Dragonflies and Damselflies of the West, by Dennis Paulson
Mammals of North America, Second Edition, by Roland W. Kays and
Don E. Wilson
Nests, Eggs, and Nestlings of North American Birds, Second Edition,
by Paul J. Baicich and Colin J. O. Harrison
Trees of Eastern North America, by Gil Nelson, Christopher J. Earle, and
Richard Spellenberg, Illustrations by David More, Edited by Amy K. Hughes
Trees of Western North America, by Richard Spellenberg, Christopher J. Earle,
and Gil Nelson, Illustrations by David More, Edited by Amy K. Hughes
Trees of Panama and Costa Rica, by Richard Condit, Rolando Pérez, and
Nefertaris Daguerre
Gil Nelson, Christopher J. Earle,
and Richard Spellenberg
Illustrations by David More
Edited by Amy K. Hughes
Trees of
Eastern
North
America
Princeton University Press
Princeton and Oxford
Copyright © 2014 by Gil Nelson, Christopher J. Earle, Richard Spellenberg, and
Amy K. Hughes
Illustrations © 2014 David More
Requests for permission to reproduce material from this work should be sent to
Permissions, Princeton University Press
Published by Princeton University Press, 41 William Street, Princeton, New
Jersey 08540
In the United Kingdom: Princeton University Press, 6 Oxford Street, Woodstock,
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press.princeton.edu
Cover art © 2014 David More
All Rights Reserved
ISBN 978-0-691-14590-7
ISBN (pbk.) 978-0-691-14591-4
Library of Congress Control Number: 2013945913
British Library Cataloging-in-Publication Data is available
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10 9 8 7 6 5 4 3 2 1
CONTENTS
Introduction 7 Canellaceae: Wild Cinnamon Family 180
About Th is Book 7 Cannabaceae: Hemp Family 182
Taxonomy and Names 8 Capparaceae: Caper Family 188
Gymnosperms and Angiosperms 8 Casuarinaceae: She-oak Family 190
Tree Biology 9 Cecropiaceae: Cecropia Family 192
Forest Structure 18 Celastraceae: Staff Tree Family 193
Leaf and Twig Keys 19 Cercidiphyllaceae: Katsura Tree Family 202
Winter Twigs of Selected Eastern Trees 20 Chrysobalanaceae: Coco Plum Family 203
Key to the Gymnosperms by Leaf Type 25 Clethraceae: Witch Alder Family 204
Key to Selected Angiosperm Trees Clusiaceae: Garcinia Family 205
by Leaf Shape 26 Combretaceae: White Mangrove Family 208
Cornaceae: Dogwood Family 214
Cyrillaceae: Titi Family 222
THE TREES Ebenaceae: Ebony Family 224
Elaeagnaceae: Oleaster Family 226
Gymnosperms 34 Ericaceae: Heath Family 228
Conifers 34 Euphorbiaceae: Spurge Family 236
Ginkgoaceae: Ginkgo Family 35 Fabaceae: Bean or Pea Family 248
Araucariaceae: Araucaria Family 36 Fagaceae: Beech or Oak Family 294
Cupressaceae: Cypress Family 38 Hamamelidaceae: Witch-hazel Family 350
Pinaceae: Pine Family 51 Illiciaceae: Star Anise Family 352
Taxaceae: Yew Family 78 Juglandaceae: Walnut Family 353
Lauraceae: Laurel Family 368
Angiosperms 80 Leitneriaceae: Corkwood Family 378
Monocots 80 Lythraceae: Loosestrife Family 379
Arecaceae: Palm Family 80 Magnoliaceae: Magnolia Family 380
Malpighiaceae: Malpighia Family 391
Dicots 98 Malvaceae: Mallow Family 392
Acanthaceae: Acanthus Family 98 Melastomataceae: Melastome Family 402
Adoxaceae: Moschatel Family 99 Meliaceae: Mahogany Family 403
Altingiaceae: Sweetgum Family 106 Moraceae: Mulberry Family 406
Anacardiaceae: Cashew Family 108 Moringaceae: Horseradish-tree Family 418
Annonaceae: Custard Apple Family 118 Muntingiaceae: Muntingia Family 418
Apocynaceae: Oleander Family 122 Myoporaceae: Myoporum Family 420
Aquifoliaceae: Holly Family 126 Myricaceae: Wax Myrtle Family 420
Araliaceae: Ginseng Family 142 Myrsinaceae: Myrsine Family 424
Asteraceae: Aster Family 146 Myrtaceae: Myrtle Family 426
Betulaceae: Birch Family 147 Nyctaginaceae: Four-o’clock Family 444
Bignoniaceae: Bignonia Family 166 Nyssaceae: Tupelo Family 446
Boraginaceae: Borage Family 174 Oleaceae: Olive Family 450
Burseraceae: Torchwood Family 178 Paulowniaceae: Princesstree Family 466
Cactaceae: Cactus Family 180 Picramniaceae: Bitterbush Family 468
6 contents
Pittosporaceae: Cheesewood Family 469 Staphyleaceae: Bladdernut Family 665
Platanaceae: Planetree Family 470 Styracaceae: Storax Family 666
Polygonaceae: Buckwheat Family 472 Symplocaceae: Sweetleaf Family 670
Proteaceae: Protea Family 474 Tamaricaceae: Tamarisk Family 672
Punicaceae: Pomegranate Family 475 Theaceae: Tea Family 676
Rhamnaceae: Buckthorn Family 476 Theophrastaceae: Joewood Family 680
Rhizophoraceae: Red Mangrove Family 488 Ulmaceae: Elm Family 682
Rosaceae: Rose Family 489 Verbenaceae: Vervain Family 692
Rubiaceae: Madder Family 562 Ximeniaceae: Ximenia Family 696
Rutaceae: Citrus or Rue Family 572 Zygophyllaceae: Caltrop Family 698
Salicaceae: Willow Family 586
Sapindaceae: Soapberry Family 618 Acknowledgments 700
Sapotaceae: Sapodilla Family 646 Abbreviations 701
Schoepfiaceae: Schoepfia Family 658 Glossary 702
Simaroubaceae: Quassia Family 659 Index of Species 707
Solanaceae: Nightshade Family 661
introduction
7
■ ABouT ThIS Book TAxonomIc orGAnIZATIon And
SeQuence oF SPecIeS
Th is guide presents the trees that grow without the Species are arranged in the book in a manner
aid of human cultivation in the eastern portion of that refl ects the general relationships among spe-
North America north of Mexico. For the purpose cies and, at the same time, provides a sequence
of this book, we have chosen the 100th meridian as convenient for the user. Th e fi rst part of the book
the division between East and West. In the United covers gymnosperms (conifers and their relatives);
States this meridian defi nes the eastern border of the larger group of trees called angiosperms (fl ow-
the Texas panhandle, extends northward across the ering plants) follows, fi rst with the monocotyle-
central portion of the Great Plains, and in Canada dons (monocots; essentially the palms), then the
lies slightly east of the borders between Saskatch- dicotyledons (dicots). See “Gymnosperms and
ewan and Manitoba, and Northwest Territories and Angiosperms” for more on these groups. Within
Nunavut. Southward, in Texas, there is a notable the gymnosperms, the monocots, and the dicots,
diff erence in the species composition of the woody the trees are organized into families, within each
vegetation that lies east or west of a dividing line family into its genera (singular, genus), and within
that continues south from the panhandle’s east- each genus the species that occur in the East. Fami-
ern border to Abilene, then curves eastward near lies, genera, and species are generally presented in
the eastern edge of the Edwards Plateau, passing alphabetic order, except in cases where juxtaposi-
through Austin and ending at Corpus Christi on tion of similar species is helpful for identifi cation.
the Gulf of Mexico.
nAmeS
nATIVe And InTroduced We use up-to-date scientifi c names, drawn from
We indicate in the tree descriptions whether a spe- the Flora of North America North of Mexico (www.
cies is native or introduced to the region covered efl oras.org), the USDA PLANTS Database (www.
by this book. Most are “native,” meaning they were plants.usda.gov), and recently published technical
already in North America before Europeans came literature. We use a unique scientifi c name for each
to the New World. Since then many trees have species. We also provide at least one, and oft en sev-
been introduced as ornamentals, to provide food, eral, common names, some of them regional (see
browse, or wood products, or for erosion control “Taxonomy and Names,” below).
or windbreaks. Some of these trees are naturalized:
Th ey are reproducing and persisting as popula- deScrIPTIonS
tions without the aid of horticultural practice. A Each family, genus, and species has its own de-
few prominent cultivated street and garden trees scription, except when a genus has only one species
are also included. in the East; in such a case there is only one inclusive
genus and species description. Family and genus
descriptions describe the group and provide some
information on how the plants are used, their ecol-
ogy, and, sometimes, problems of classifi cation.
Species descriptions begin with common and
scientifi c names, including alternative names
(“a.k.a.”), if any. For all native species (and many
introduced) we provide a “Quick ID,” a short state-
ment describing how to recognize quickly that
particular species. A more detailed description fol-
lows, providing information on habit (the plant’s
growth form), bark, twigs, foliage, fl owers, and
fruit. Descriptions vary in length depending on our
assessment of the cultural or ecological importance
of the tree as well as the extent of its geographic dis-
tribution. We indicate whether the species is native
or introduced, and describe the usual fl owering pe-
WEST EAST
WEST EAST riod, elevation and general habitat, and geographic
Th is guide covers the eastern United States and Canada distribution. When applicable, we explain how to
as indicated on the map. distinguish the species from similar, usually closely
88 IInnttrroodduuccttIIoonn
related species. For nearly all native and some intro- about organisms, and affords ready information re-
duced species we provide a thumbnail map showing trieval from references. Scientific names inform us,
the general geographic range of the species in North for example, that Live Oak (Quercus virginiana) and
America north of Mexico. Water Oak (Quercus nigra) are related, both being
in the genus Quercus; but that Eastern Poison-oak
(Toxicodendron pubescens) and the she-oaks (spe-
■ TAxonomy And nAmeS cies of Casuarina) are not related to one another or
to Quercus, despite being called “oaks.”
Taxonomy defines groups of organisms, gives names The scientific name is a Latinized name, Latin
to the groups, and arranges them in a hierarchy, being the primary language of science in the 18th
thereby producing a classification. It is the oldest of century, when the system was devised. It is a two-
biological sciences, originating in descriptions of or- part name, or binomial, composed of a genus name
ganisms in nature. Modern classifications use many followed by a specific epithet. The binomial, together
lines of evidence, including morphology, chemistry, with the author’s name, is the complete scientific
and DNA-based data, to classify organisms accord- name for a plant. The first part is a noun, referring
ing to their evolutionary relationships. At the higher to a kind of plant (sumac, oak). The specific epithet
levels of the hierarchy, those relationships are still is usually an adjective that describes the species or
unclear; in this book we use the traditional names commemorates a person. Rhus glabra, the scientific
angiosperms, gymnosperms, monocots, and dicots. name for Smooth Sumac, provides an example: Rhus
At the lower levels of the hierarchy, we use the for- derives from an ancient Greek name for sumac;
mal ranks of family, genus, and species, which form glabra, derived from the Latin for “bald,” refers to the
a useful framework for identification. absence of hairs on plant parts. The names or abbre-
It is useful to be able to recognize plant families; viations that follow the binomial indicate the author
knowing their characteristics makes identification or authors (also called the authority or authorities)
easier and can give one some familiarity with local who named and described the plant. Rhus glabra is
plants in any part of the world. Families are col- followed by “L.,” for Carolus Linnaeus, the Swedish
lections of genera that share a common ancestor. botanist who is credited with developing the bino-
New interpretations, often reached through DNA mial system 260 years ago. When a named species
analysis, are producing ongoing changes in our is later understood to belong to a different genus,
understanding of some traditional plant families. the specific epithet may be moved from one genus
The former maple family (Aceraceae), for exam- to another. The name of the author who first named
ple, does not appear in this book; maples (genus the plant is placed in parentheses, followed by the au-
Acer) are now placed within the soapberry family thor who moved the name to a different genus. How
(Sapindaceae). For the most part, we have adopted names are applied and moved about is regulated by
new family alignments, but in a few cases where it a set of rules, the International Code of Nomenclature
helps identification, we have maintained tradition- for algae, fungi, and plants (www.iapt-taxon.org).
al families. We explain the newer, often tentative,
classification whether we adopt it or not.
■ GymnoSPermS And
SPecIeS nAmeS AnGIoSPermS
As strange as it may seem, the precise definition
of a plant species has been argued for decades. For Two great groups of land plants bear ovules, which
our use, it is a group of populations that persists in when fertilized produce seeds. The seed has an
nature, sufficiently distinct to bear a name. Most outer protective layer that surrounds a nutritive tis-
species have one or more common names, but sue, the endosperm, to be used by the germinating
common names differ among the world’s many lan- embryo that developed from the fertilization of an
guages, as well as regionally, and often do not indi- egg within the ovule. The seed plants are tradition-
cate relationships among species. Furthermore, one ally divided into angiosperms and gymnosperms.
species may have several common names, or sev- We retain those terms in this book.
eral species may have the same common name. The The conifers and their allies, the Ginkgo, cycads,
two-part scientific name assigned to each species and gnetophytes, comprise the gymnosperms, a term
applies to only one species. It distinguishes by name derived from the Greek words for “naked seeds.”
one species from another, indicates some degree of The ovules of these plants are not protected within a
relationship, allows international communication closed ovary, as they are in the angiosperms, but are
tree BIoLoGY 99
margins fuse,
borne directly on structures that expose them to the
forming a
environment at the time of pollination, although leaf folds single carpel
the ovules are oft en protected to some degree by
overlapping scales. Technically, the endosperm in
gymnosperms has a diff erent origin than that of
the angiosperms, that diff erence further helping to
distinguish the two groups. Most gymnosperms are
pollinated by wind, but many cycads are pollinated
by insects. In conifers and gnetophytes, as in angio-
sperms, the pollen grain grows a pollen tube that
conveys sperm to, or even within, the ovule, where leaf with
the egg is fertilized. In Ginkgo and the cycads, how- exposed ovules
ever, fertilization occurs when motile sperm swim
from the pollen grain into the ovule. several carpels
While there is considerable ongoing scientifi c fuse, forming
debate about how closely related the groups within a compound
the gymnosperms are, it is clear that the gymno- pistil
sperms were formerly a highly diverse group, of
which only a comparatively few families have sur-
vived to the present.
Th e other group of seed plants is the angio-
sperms, a term derived from Greek words meaning Evolution of the Carpel
“vessel” and “seed,” referring to a plant with seeds
borne within an enclosure. Angiosperms evolved typically have two. In addition, monocots usually
from gymnosperms around 200 million years ago, have fl owers with parts in multiples of three and
when a leafl ike, ovule-bearing structure in a seed leaves with a number of conspicuous parallel veins.
fern closed around its ovules (which when fertilized Dicots usually have fl owers with parts in multiples
develop into seeds), producing a carpel. Th e fl ower, of four or fi ve, and net-veined leaves with main
characteristic of angiosperms, became an organ- veins branching in a pinnate or palmate pattern,
ized reproductive structure consisting of carpels, interconnected by a conspicuous net of minor veins.
stamens, petals, and sepals. Th e carpel is the funda-
mental unit of the pistil, the pollen-receiving, seed-
producing part of the fl ower. Th ere are two types of ■ Tree BIoloGy
pistils: those composed of a single carpel (a simple
pistil); and those composed of two or more carpels Th ere is no scientifi c diff erence between a tree and
joined together (a compound pistil). One can usu- a shrub, although in general conversation a tree is
ally determine the number of carpels in a pistil by understood to have a single woody stem (a trunk)
counting the number of chambers (or locules), but and a well-defi ned crown of branches. In this book
because chamber walls are sometimes incomplete we include such plants, large and small, along with
or absent in a compound pistil, the number of a number of plants generally taller than a human
branches on the stigma (the pollen receptor at the that may be thought of as shrubs, oft en growing
tip of the pistil) is also usually a reliable indicator; with multiple woody trunks.
two or more branches suggest a compound pistil.
Th e diagram above illustrates the evolution of the
carpel from an ovule-bearing leaf, and the develop-
6 petals
ment of a compound pistil from a fusion of several parallel main 5 petals
carpels. Two other features that distinguish angio- veins
sperms from gymnosperms are the seed-bearing
closed fruits, and the way the endosperm develops.
Angiosperms are divided into the Monocotyledo- netlike
neae, or monocots, and Dicotyledoneae, the dicots. veins
Th e names refer to the number of embryonic, oft en
nutrient-storing leaves in the embryo within the
seed: monocots typically have one, whereas dicots Monocot Flower and Leaf Dicot Flower and Leaf