Habit
Note: Some plants are categorized in more than one of the following habits as appropriate to their
characteristics.
Agave-like plant
Perennial monocot plants with long, narrow, often rigid and "bayonet-like" leaves, these succulent or hard
and durable, long-lived, often spine-tipped and sometimes with spiny margins, produced as a rosette or
terminal cluster. "Agave-like" species grow mostly in arid regions and now are mostly placed in genera of
the Agavaceae and Liliaceae (Agave, Manfreda, Hesperaloe, Yucca, Nolina, Dasylirion in North
America). In this category are species with characteristically tall trunks (e.g., Yucca brevifolia) as well as
those without trunks or with trunks of variable length (e.g., Agave lechuguilla). Agave-like species with a
distinctive trunk-like portion are here also categorized as trees.
Bamboo or cane
Perennial grasses with woody, usually hollow stems (culms) with conspicuously ringed nodes, usually
clonal from a system of rhizomes and producing many tall, erect stems from the base. Technically,
bamboos comprise subfamily Bambusioideae of the grass family (Poaceae) and in our flora include
Arthrostylidium, Arundinaria, Bambusa, Chusquea, Phragmites, Phyllostachys, Pseudosasa, Sasa, and
Schizostachyum. Other tall, woody-culmed grasses in our flora, referred to as "canes" or "reeds," are
similar in habit to bamboos but have developed independently in various groups of the family: Arundo and
Phragmites (Arundinoideae) and Lasiacis and Saccharum (Panicoideae). Bamboos and canes are
primarily subtropical or tropical in their native distribution.
Cactus-like
Generally spiny and succulent plants mostly of arid habitats represented by the family Cactaceae or
plants appearing to be cactus-like in growth form.
Cycad or palm-like plant
Cycads, palms, and other similar perennial plants with terminal clusters of large, strong, and durable
leaves, often to 1 meter or more wide, usually palmately or pinnately divided into long segments at the
end of a long petiole. Palms and cycads are mostly tropical or subtropical. In this category are included
species with characteristically tall trunks (e.g., Cocos nucifera) as well as those without trunks or with
trunks of variable length (e.g., Sabal minor and Zamia pumila). Palm-like species with a distinctive trunk-
like portion are here also categorized as trees.
Dwarf shrub
Diminutive woody plants that are generally lignaceous or sufrutescent at least at the base or more
commonly throughout. Dwarf shrubs often represent plants on the forest floor, but can also become
established as woody-based herbs of open areas where especially common in the Malvaceae and
Asteraceae.
Epiphytic/hemi-epiphytic plant
Non-parasitic plants that grow exclusively upon and are anchored to other plants.
Fern or fern-ally
The pteridophytes as traditionally treated: spore-producing but flowerless and seedless vascular plants
that are usually differentiated into roots, stems, and leaf-like fronds.
Fern (tree)
Large ferns with tree-like growth habit represented by 3 families (Blechnaceae, Cyatheaceae, and
Dicksoniaceae) that grow mostly in humid, tropical areas.
Forb
Herbaceous plants most commonly with relatively broad, usually pinnately veined leaves (contrasted with
parallel-veined in "grass or grass-like" plants), with all perennating or overwintering organs at or below
ground level. The forb category, which was originally established in an agricultural context to contrast
with grass and grass-like plants, includes a wide range of herbaceous growth habits, especially if aquatic
plants are added. Vining, creeping, and trailing herbs also are included within this broad category (in the
BONAP system). Plants with annual stems becoming woody at the base are included as forbs. Primarily
herbaceous plants bearing terminal buds at the tips of woody caudex branches at or near ground level
are referred to the forb category; "cushion plants" belong with these. However, members of the genus
Rubus, which is weakly woody, have been scored broadly as shrubs and subshrubs, and are sometimes
characterized as "succulent shrubs."
Grass or grass-like (graminoid) plant
Herbaceous plants with long, narrow, entire, parallel-veined leaves, often produced in a basal cluster,
with all perennating or overwintering organs below the ground. The flowers of these plants usually are
reduced in complexity and thus inconspicuous. Grasses and grass-like plants include all members of the
monocot families Cyperaceae, Juncaceae, Juncaginaceae, and Poaceae, some members of the
Liliaceae, and all members of the pteridophyte family Isoetaceae, but similar leaved-species occurring in
numerous dicot families were not scored. Bamboos and canes, which are woody and often have above-
ground perennation, are included here but are also placed in a separate category.
Shrub
Perennial plants with woody, above-ground stems that bear overwintering buds relatively evenly
positioned on the stems and do not die back to a basal stem or rhizome in winter. Shrubs are multi-
stemmed from the ground, generally attaining a low stature (variable in size but usually under 5 meters
tall), and producing a poorly-defined crown. Some shrubs may be creeping (e.g., Juniperus horizontalis,
Gaultheria hispidula); others may be "mat-like" or "mound-like" (e.g., Arctostaphylos nevadensis).
Various exceptional species are also placed here (e.g., Coreopsis gigantea, a "fleshy-stemmed shrub";
Coreopsis maritima, a "hollow-stemmed shrub"; Leucanthemum nipponicum, a "soft shrub"), and some
primarily shrubby species that occasionally reach tree size are also characterized as trees. All mistletoes
(Viscaceae) are scored as shrubs as well as parasites, following other precedents. Members of the
genus Musa, although herbaceous, are also scored as shrubs and subshrubs.
Subshrub
Perennial (rarely annual or biennial) plants with woody or lignescent above-ground stems but with
overwintering buds only near the base of the plants, most of the stem dying back to near ground level
each year and the upper part of the plant mostly herbaceous. They are often termed "suffruticose"
plants. Subshrubs are usually multiple-stemmed from the base and of low stature, but some may attain
1-few meters in height. The habit in some species that produce large plants grades into "shrubs" and the
distinction between shrub and subshrub becomes arbitrary. Species that might be categorized as
subshrubs, however, show more variation than true shrubs in the degree of woodiness and overall size.
Most of such habit intergradation occurs in western North America, where species of subshrubs are most
numerous. Intergrades between subshrubs and "forbs" also are common. Some species produce tall,
thick, and woody but annual stems (e.g., Sesbania spp., Helianthus spp., many Malvaceae), either
completely by primary growth or sometimes with the addition of secondary wood. These are placed here
in both the forb and subshrub categories, but they are even characterized by some botanists as shrubs.
All species of Rubus and Rosa have been scored as subshrubs.
Tree
Perennial plants with woody, above-ground stems that bear overwintering buds and do not die back to a
basal stem or rhizome in winter. Trees usually have a single main stem, are at least 4 meters tall, and
have a more or less distinct and elevated crown. A few species produce normally short-lived but rapidly
growing plants that occasionally attain tree-like proportions (e.g., Ricinus communis). Likewise, members
of the Musaceae treated within the Synthesis, although herbaceous, are scored as trees.
Vine
Perennial, biennial, or annual herbaceous, semi-woody, or woody plants with elongated, flexible stems
supported above the ground via twining, sprawling, clambering, or climbing by tendrils or other modified
organs over other plants or structures. All herbaceous vines as here characterized are also scored as
forbs.
Aerial roots
Mostly adventitious above ground roots that help to anchor plant stems to vertical surfaces that are
found commonly in Hedera helix and Toxicodendron radicans.
Liana (woody vine)
Perennial plants with woody or lignescent above-ground stems that grow upward and into (or onto)
trees and other vegetation or structures. They bear overwintering buds and do not die back to a
basal stem or rhizome in winter. Lianas can often have weak, elongate, and flexible stems and gain
support by twining, clambering, or climbing with tendrils, aerial rootlets, or other modified structures.
Tendrils
Usually slender, forking, or simple modified leaves or portions of leaves that aid in supporting plant
stems that are vining or twining. Two forms are distinguished in the Synthesis:
Tendrils with disks
Tendrils that terminate in small, plate-like structures, which appear as thin disks.
Tendrils without disks
Usually slender, forking, or simple modified leaves or portions of leaves that aid in supporting plant
stems that are vining or twining.
Habitat
Alpine to subalpine plant
Plants found growing at high elevations or at far northern (or far southern) latitudes, above, at, or only
slightly below tree line, and extending to the permanent show and ice cover. Regrettably, the alpine flora
of Hawaii is only superficially represented within the Synthesis. I welcome any additional input to make
the list more complete for that area.
Aquatic plant
Plants that at maturity and under normal water levels grow submerged or floating on the water surface,
but not emerging substantially above the water surface.
Freshwater plant
Plants that spend much or all of their existence in rivers, streams, lakes or other freshwater habitats.
Marine plant
Plants that spend much or all of their existence in seawater or along ocean shoreline or in shallow
seas.
Emergent plant
Aquatic or wetland macrophytic plants with their roots periodically submerged or below water and
their foliage entirely or partly above the water level.
Floating plant
Aquatic plants that at maturity and under normal water levels grow completely free floating on the
water surface, or have their leaves floating on the water surface.
Submerged plant
Aquatic plants that at maturity and under normal water levels produce their stems and leaves
principally under water.
Vernal pool plant
In North America, vernal pools are restricted to California where they represent very fragile
seasonally flooded, shallow depressions, mostly in alluvial valleys that form on very old hardpan or
volcanic basalt that fill with water primary from winter rains and remain wet late into the season.
Vernal pools are dominated heavily by native annual plants that are often considered rare,
endangered and often endemic to these habitats.
Wetland plant
Plants growing in aquatic or wetland habitats. These include all known floating, submerged, and
emergent taxa, plus those that are found in permanently or seasonally wet habitats.
Note: Species of wetland plants as here presented are not necessarily those designated as wetland
plants by the U.S. Fish and Wildlife Service.
Chaparral plant
A densely shrubby plant community often dominated by heaths and other plants with mostly thick-leathery
evergreen leaves. In North America, chaparral habitats are found primarily in Arizona, California and
Mexico.
Epiphytic/hemi-epiphytic plant
Non-parasitic plants that grow exclusively upon and are anchored to other plants.
Redwood forest plant
Plants restricted to indigenous Pacific coastal habitats from southern Oregon to California, dominated by
the evergreen conifer, Sequoia sempervirens (California Redwood).
Serpentine
A unique series of mineral rich soil with heavy concentration of magnesium silicate. Serpentine minerals
are green or greenish in color. In North America, these mineral concentrations are found mostly in
eastern Canada and northeastern U.S., also in California, Oregon to Arizona and scattered elsewhere in
areas of the Pacific Northwest.
Morphology
Achlorophyllous plant
Plants lacking the green pigment chlorophyll found in all photosynthetic plant cells.
Armed plant
Plants that produce various types of sharply-pointed structures such as thorns, spines, prickles, or
specialized hairs. These structures can be produced on any part of the plant, including fruits, cones,
stems, leaves, inflorescences, etc. Due to the difficulty and ambiguity of this field, it is not yet fully
populated.
I have taken the liberty to include members of the Urticaceae, since many of its species have painfully
sharp specialized trichombs, but have not done so with other members of the Boraginaceae, since they
are generally not as mechanically injurious. I have also been somewhat selective by including certain
members of the genus Galium, i.e., those species with mostly sharply-spined leaf apices, but have
ignored other members of the genus with only specialized stem hairs. In a few cases, I have also
included species of genera (Euonymus, Planera) with fleshy protuberances on their fruits. Any comments
would be welcomed.
Bulb plant
Plants having bulbs; a bulb is a short stem axis surrounded by thick, fleshy, modified leaves, producing a
broadly ovoid, underground storage organ. The whole bulb is equivalent to a "shoot" - a leafy stem.
Bulbs, in this strict definition (which is used here), are restricted to two monocot families (Iridaceae and
Liliaceae) and one dicot family (Oxalidaceae). The bulbous habit has arisen independently several times
even within a single section of Oxalis. Plants of some species arise from a "bulbous-thickened base"
(e.g. Xyris isoetifolia, Poa bulbosa, Luzula bulbosa), where the thickening is produced from the leaf bases
of functional, above-ground leaves.
Bulblets, which are miniature bulbs usually significant in asexual reproduction, are characteristic of some
genera, e.g., Luzula (Juncaceae), Bolandra and Suksdorfia (Saxifragaceae), Dicentra (Fumariaceae),
Oxalis (Oxalidaceae), Calochortus (Liliaceae). They may be produced in various places, such as rhizome
tips or the axils of cauline leaves ("bulbels") or bulb scale leaves ("bubils"). Production of bulblets as a
biological attribute is not included in this version of the Synthesis.
Some working definitions of "bulb," especially in horticultural contexts, are broadened to include various
other types of underground storage organs, such as swollen stems (corms, rhizomes, tubers) and swollen
roots ("tuberous roots"). Various descriptions and epithets referring to bulbs technically refer to other
types of structures (e.g., Cardamine bulbosa - tuber, Cicuta bulbifera - tuberous roots, Dioscorea
bulbifera - tuber, Erigenia bulbosa - tuber, Ranunculus bulbosa - corm).
Corms also are swollen, underground storage organs equivalent to a "shoot," but the stem (rather than
the leaves) is swollen and bears few to numerous, thin, scale-like leaves that do not provide storage
capacity. Corms also are relatively common among monocots but are produced within only a few genera
of dicot families (e.g., Anemone, Eranthis, and Ranunculus - Ranunculaceae; Cyclamen - Primulaceae;
Begonia - Begoniaceae; Achimenes, Gesneria and Gloxinia - Gesneriaceae; Corydalis - Fumariaceae).
Corms with few, small leaves may approach tubers in their technical definition. The "scaly bulbous base"
of some species of Oxalis, where the leaves are dry and scaly relative to a typical monocot bulb, might be
considered somewhat intermediate between a bulb and corm.
Geophyte
Perennial plants that bear their overwintering buds below the surface of the soil on bulbs, corms, tubers,
or in some cases, rhizomes.
Stem texture
Herbaceous plant
Non-woody plants lacking a persistent, woody, above-ground stem.
Semi-woody plant
Plants producing a suffrutescent or obscurely ligneous stem with limited woody tissue.
Woody plant
Plants producing a ligneous stem, primarily resulting from secondary xylem.
Trailing or creeping
Low growing, often colonial plants that generally lack twining appendage such as tendrils, but can
form large continuous mats.
Duration
Annual plant
Plants in which the entire life cycle is completed within one growing season.
Biennial plant
Plants that normally require two seasons to complete their life cycle; a basal rosette of leaves is produced
in the first season, followed by flowers and fruits in the second season.
Perennial plant
Plants persisting year after year, producing reproductive structures in two or more different years.
Major Plant Group
Gymnosperm
As traditionally treated: woody vascular seed plants that produce naked seeds (not enclosed within an
ovary).
Flowering plant
Vascular plants that produce true flowers and fruits that bear seeds.
Monocot flowering plant
Members of a biological class of angiosperms (flowering plants) having embryos with a single cotyledon.
Most monocots generally have the following characteristics:
1. Principal leaf veins produced in parallel pattern from the base.
2. Leaf margins nearly always entire.
3. Flower parts arranged in threes or multiples of three.
4. Root system fibrous, lacking a taproot.
5. Vascular bundles of the stem scattered throughout, not formed in a cylinder or ring.
6. Plants rarely woody (Arecaceae and Smilacaceae are exceptions), stems lacking a cylindric
cambium.
7. Embryos with one cotyledon.
Dicot flowering plant
Members of a biological class of angiosperms (flowering plants) having embryos with two cotyledons.
Most dicots generally have the following characteristics:
1. Principal leaf veins branched from the midrib or from its base.
2. Leaf margins entire or toothed.
3. Flower parts arranged in twos, fours, fives, or indeterminate.
4. Root system commonly a taproot with branched roots.
5. Vascular bundles of the stem produced in a single cylinder or ring (cross-section).
6. Cambium of woody plants produced in a new ring annually.
7. Embryos with two cotyledons.
Nativity
Native plant
Plants that occur naturally in a particular geographic area without direct or indirect human intervention.
For the purpose of the Synthesis, a plant native to any area within the geographic range of the Checklist
is considered to be native. For this edition, no designation has been made to indicate state-level nativity.
Exotic plant
Plants from foreign areas (for the purpose of the Synthesis, those that occur outside of North America
north of Mexico) that have been released intentionally or unintentionally or have been disseminated or
escaped as a result of human activity, and become established somewhere within the geographic range
treated by the Synthesis.
A total of 3,802 exotic species, or 17.3% of the North American flora, is known to occur within the
geographic area treated. For all U.S. states, there is an average of approximately 610 exotic species per
state, or an average of 21% of each state's flora. For all Canadian provinces, there is an average of
approximately 340 exotic species per province, or 21% of each provincial flora. Thus, the average
percentage of exotic species per U.S. state and Canadian province is identical.
Taxonomy
Taxonomy is the science of classification that uses as one of its most fundamental underpinnings a
system of nomenclature (naming). The word taxonomy comes from the Greek words taxis (meaning
“order” or “arrangement”) and nomos (“law” or “science”). The Swedish botanist Carolus Linnaeus (1753)
is credited with putting into wide usage his binomial (“two-name”) classification system (one name to
indicate the genus and one to indicate the species).
Traditional plant taxonomy
Commonly referred to as Linnaean systematics or organismal biology, traditional taxonomy is a type of
classification that considers the whole organism or group of organisms. It is based primarily upon
morphological features, most often those related to reproduction, and other phenotypic traits. Individuals
considered to be members of the same species are reproductively isolated from other species, share a
common gene pool, share morphological characters, and display certain geographic distribution patterns
based upon similar habitats. These and other shared characters provide a system of relationships that
defines the boundaries of species, genera, families, etc.
Molecular plant taxonomy
Molecular plant taxonomy, or phylogenetics, is a method of classification that uses DNA sequences to
analyze evolutionary relationships, with the results portrayed in tree-like diagrams called dendrograms.
These types of genetic analyses can be done at the population, species, genus, or higher taxonomic
levels. In recent years, morphological characters, habitat, and geographic patterns have been
incorporated into the analyses. In many instances, phylogenetic relationships used to support a molecular
classification differ dramatically from those determined through traditional taxonomy. It is now believed
that many of the morphological characters that traditional taxonomists weighted heavily in distinguishing
taxa at various taxonomic ranks have resulted from convergent evolution. The genetic discovery of these
convergent evolutionary features that were used in earlier traditional taxonomic classifications explains
why many genera and even entire families have been repositioned in the molecular taxonomy
classification system. In other instances, individuals thought to belong to a single species based on
limited morphological variation have been shown to belong to multiple species based on DNA sequence
data that shows substantial genetic differentiation.
Traditional vs. Molecular plant taxonomy
Over the past three decades the results of these two taxonomic methodologies have generally agreed,
but sometimes have differed markedly. The contrasting results have lead to reexamination and
reevaluation of morphology and other characters used in traditional taxonomy to gain further insights into
evolution of various groups. In this manner traditional taxonomy continues to improve. Taxonomy based
on morphology clearly remains extremely important: in fact, it still represents the most readily apparent
means of classifying biological diversity. Furthermore it is the easiest system to teach, especially to field
biologists where only morphological characters are available for examination. For these reasons, we felt it
necessary to include both systems of classification.
Nomenclature
Scientific names, consisting of genus and species, mostly of either Greek or Latin origin, make up the
binomial. An example is Acer rubrum L., where Acer is the genus, rubrum is the species, and L. is the
author (in this case, Carolus Linnaeus, the individual who named and described the species). Scientific
names are fundamental in understanding taxonomy or classification. Taxonomy is a hierarchical system
that includes multiple levels, with each level referred to as a ra nk, beginning at the highest rank of
kingdom and terminating at the lowest rank of species or infraspecific taxa (below the species rank). Each
rank is represented by a name or epithet, which is referred to as a taxon. Infraspecific taxa, which are
most commonly included as subspecies and/or variety, are referred to as “trinomials,” e.g., Acer rubrum
var. rubrum. Here, the abbreviation “var.” stands for variety and in this case for typical variety rubrum .
Acer rubrum has three infraspecific wetland taxa, all at the variety rank, including Acer rubrum var.
drummondii, A. rubrum var. rubrum, and A. rubrum var. trilobum.
The logic that determines ranking is predicated on biological concepts supported by scientific research in
fields as varied as plant breeding, plant genetics, evolution, pollination biology, and ecology. Today, many
current taxonomic treatments for various plant groups have arisen from new interpretations of old
classification concepts and are now supported widely by new tools deeply rooted in genetic and
molecular biology, often referred to as molecular genetics or phylogenetics. Currently species boundaries
are delimited using evolutionary relationships or phylogenies predicated on molecular sequence analyses
in combination with morphological characteristics and other biological and habitat features.
Some of the types of taxonomic and nomenclatural updates that have formed the basis of the current
2009 NWPL include the following examples.
Example 1
In 1988 the eastern red cedar was treated as two distinct species: Juniperus virginiana L. and Juniperus
silicicola (Small) L.H. Bailey. It is now believed that these two species should be united as one: Juniperus
virginiana (the older of the two names), with two varietal expressions, var. virginiana and var. silicicola.
Once these two “species” were merged, the typical expression var. virginiana was automatically created
when var. silicicola was made. The var. silicicola is sometimes referred to as the nontypical expression.
This practice is applied throughout animal and plant taxonomy, i.e., once a new infraspecific taxon is
created, a typical is simultaneously and automatically created.
Example 2
In the 1988 NWPL, a single species of the genus Acorus was recognized as a wetland species. Today,
however, that single species is now recognized as two distinct species: the newly added Acorus
americanus (Raf.) Raf. (native to North America) and the pre-existing Acorus calamus L. (exotic to North
America). Thus, on the 2009 NWPL, each species has a separate wetland ranking, distribution, etc.
Example 3
A third example of taxonomy/nomenclature change is less clear and involves trinomials (Melvin 2007). In
the 1988 NWPL, three separate listings of a single species, the red maple (Acer rubrum L.), were made,
each with a separate wetland rating. With each of these three listings, an inferred (but not listed)
infraspecific taxon was assumed to be represented, including Acer rubrum var. rubrum, Acer rubrum L.
var. drummondii L., and Acer rubrum L. var. trilobum L. In part because of the confusion that ensued, all
three names were expanded in the 1996 NWPL and listed as separate taxa: Acer rubrum (typical
expression inferred), Acer rubrum var. drummondii, and Acer rubrum var. trilobum, the latter two both
implied. To further reduce any taxonomic ambiguity, in the 2009 NWPL, we specifically included and
named the typical variety Acer rubrum var. rubrum to the species complex, since it clearly represents the
most ubiquitous taxon of the species complex in North America. Therefore, in the current NWPL, we have
named all three infraspecific taxa of the red maple as stated above. A similar policy has been adopted for
all species where a typical expression exists separately from the listed non-typical expression(s).
Synonymy
For most taxa included within the Synthesis, a high degree of functional synonymy is presented by
including only "manual-level" synonyms rather than detailed or "monographic-level" synonyms. For
certain genera such as Salix, Lupinus, Crataegus, Rubus, Antennaria, and Galium, however, and for
certain Hawaiian plant genera, more complete synonymy is included to provide an accurate
understanding of the elements in these confusing and controversial genera. Despite the more detailed
treatment of these genera, the general intent of the Synthesis is to account for only the accepted names
that appear in current standard floras, monographs, revisions, and other recent floristic literature. To
have included "monographic-level" synonymy would have otherwise added nearly 270,000 more names
and tripled the number of names in the Synthesis! Although I recognize that many of the names listed in
synonymy are illegitimate under the current International Code of Botanical Nomenclature (Tokyo Code,
1994), I have nevertheless included them and show their proper disposition, since they appear in many of
our floras, manuals, and monographs. Recognizing also the misuse, misapplications, or differences in
applications of certain synonyms, I opted to use the abbreviations auct. non and (pro parte) for such
names, thereby following recommendation 47A of the International Code. In a few cases, the names of
certain taxa (e.g., Taraxacum officinale, Bidens spp.) are retained in spite of potential nomenclatural or
taxonomic problems, which may ultimately render such names illegitimate or otherwise inappropriate for
use. Until more complete understanding of these names and the taxa that they represent are available,
their traditional usage is maintained.
Taxon
A taxon (plural: taxa) is a taxonomic group of any rank. The Maple family, Aceraceae, the Maple genus,
Acer, and the Silver Maple species, Acer saccharinum, are all taxa. In a single classification, each taxon
can have only one accepted name, but may have any number of synonyms.
The term "taxon" was formally adopted for use throughout the International Code of Botanical
Nomenclature by the Sixth International Botanical Congress held in Stockholm in 1950.
Synonym
A synonym is a scientific name applied in whole or in part to a particular taxon but is not the correct
accepted name (in a particular taxonomic classification) for the taxon to which it refers.
Synonyms arise for several reasons. Because of changes in the scientific understanding of taxonomic
relationships, two species (or taxa of higher or lower rank, as well) may be merged. This will make one of
the two names a synonym of the other. Sometimes a scientific author may be unaware that someone
else has already published a name for a species. A genus may be split into two or more smaller genera.
The Synthesis attempts to list the most commonly occurring synonyms and to give the corresponding
correct accepted name.
Two common nomenclatural conventions are important to understand when considering synonymy:
The "auct. non [Author]" designation indicates that a name has been used by various authors in the sense
of the synonym under consideration but not in the strict sense of the name (based on the original
publication by the original "Author"), which refers to a different species. For example, names based on
types of European plants have sometimes been misapplied in this way to American plants. The Latin
phrase literally means "of authors, not [Author]," where "Author" refers to the author of the original name,
in its strict sense.
The "pro parte" designation (abbreviated "p.p." following the author of a scientific name, meaning "in
part") indicates that the name (as a synonym) has been used in a broad concept to include the correct,
currently accepted name under which it is listed, as well as at least one other correct, currently accepted
name. The same "pro parte" name might thus be expected to appear as a synonym in several places in
the Synthesis. Such concepts arise from taxonomic study that produces more precise circumscriptions,
clarifications of typification, or other clarifications of application.
Common Names
This topic contains the following sections:
I. Group Names
II. Guidelines for Hyphenation of Group Names
III. General Guidelines for Group Names
IV. Modifiers
V. General Guidelines for Modifiers
VI. Fanciful Phrases as Common Names
VII. General Guidelines for Spelling
VIII. General Guidelines for Capitalization
IX. True Group Names
The following information was originally published in: Kartesz, J.T. and J.W. Thieret. 1991. Common
names for Vascular Plants: Guidelines for Use and Application. Sida 14(3): 421-434 and is included
within the Synthesis with permission.
For each of the fully recognized families, genera, and species found within the Synthesis, a common
name is provided. These common names were selected using criteria listed below. Although some
individuals may disagree with these selections, they have been reviewed by numerous individuals and
groups who now use them. However, as with all other aspects of the data, I welcome any suggestions.
Common names for plants are generally composed of two parts: the first is referred to as the modifier, the
second as the group name. The modifier, usually quite variable, provides the uniqueness to each
common name at the species level. Conversely, the group name is quite constant, establishing the
identity of taxa above the species level, i.e., families, genera, subgenera, tribes, etc. Group names may
not necessarily require a modifier. In some cases, for example (usually in small genera), a single word or
fanciful phrase is all that is necessary to constitute a group name.
I. Group Names
Group names are often composed of a single word describing a particular family, genus, subgenus, tribe,
or section. These names are of three basic types:
1. SIMPLE GROUP NAMES: Simple group names are represented by a single word, e.g.
ash aster
clover fern
grass lily
mallow mustard
orchid pine
rose rush
sedge stopper
tulip willow
2. SINGLY-COMPOUND GROUP NAMES: These are group names composed of two root-words or
elements that are connected as one. Names of this type are composed of a pair of single-syllable
words or of both a single- and a double-syllable word. For these names, both words or elements
should be joined to form a single word (unless the words or elements begin and end with the same
letter, e.g. saw-wort, cat-tail), e.g.
bloodleaf chickenthief
goldenrod hawkweed
hawthorn lousewort
mousetail nipplewort
quillwort rockcress
sneezeweed waternymph
3. DOUBLY-COMPOUND GROUP NAMES: Doubly-compound group names represent the most
complex type. These are names composed of two or more distinct words or elements totaling four or
more syllables. Each word or element of this type is separated from the others by a hyphen. These
names may be subdivided into the following four categories:
a. Doubly-compound group names with two words, each word having two or more syllables, e.g.
Kenilworth-ivy monkey-flower
morning-glory popcorn-flower
pygmy-melon roving-sailor
treasure-flower trumpet-creeper
water-horehound yellow-saucers
b. Doubly-compound group names with two words, one word with three or more syllables, the
other word with a single syllable, e.g.
butterfly-weed burr-cucumber
pincushion-plant rattlesnake-root
strawberry-tree scorpion-tail
unicorn-plant vegetable-sponge
c. Doubly-compound group names with three or more words, e.g.
pale alpine-forget-me-not (alpine is part of the group name, not a modifier)
arctic sweet-colt’s-foot (sweet is part of the group name, not a modifier)
NOTE: In the above examples, since the words alpine and sweet precede taxonomically incorrect
group names, they are set off by hyphens. These examples differ from the two that follow, which
include taxonomically incorrect groups (see Section IX for a discussion of true groups), e.g.
d. Doubly-compound group names similar to those of category c, but differ by having a "false
modifier" as part of the group name, e.g.
fringed yellow star-grass (yellow is part of the group name "yellow star-grass," and is not a
true modifier)
Sonoran false prairie-clover (false is part of the group name "false prairie-clover," and is not a
true modifier)
In these cases, neither the modifier nor the "false modifier" should be connected by a hyphen to
what follows.
II. Guidelines for Hyphenation of Group Names
Group names should be hyphenated only under the following conditions:
1. when the group name is composed of two words or elements, with each word or element beginning
and ending with the same letter, e.g.
cat-tail desert-thorn
five-eyes saw-wort
trumpet-tree yellow-wood
2. when the group name is doubly-compound, i.e., when each word or element of a pair has two or
mote syllables, or when either element of the pair has three or more syllables (see I-3a and I-3b
above).
3. when the final word or element of the group name is taxonomically misapplied (unless historically
spelled as a single word, e.g., buckwheat, toadflax), e.g.
star-grass (not a grass of the Poaceae)
poison-oak (not an oak of the genus Quercus)
water-lily (not a lily of the genus Lilium)
NOTE: See extended listing below for taxonomically true groups (Section IX).
4. when three or more words or elements comprise the group name (see I-3c above).
5. when a word or element of a group name includes an apostrophe, e.g.
adder's-mouth orchid bishop's-cap
Jacob's-ladder mare's-tail
Solomon's-seal St. John's-wort
NOTE: Hyphens should never be used for a group name to set off the words false, mock, wild, or
true, since the status is already suggested by the existing modifier. Nor should the unconventional
use of hyphens be included in canonizations or in titles of individuals, e.g.
Aunt Lucy (not Aunt-Lucy)
Good King Henry (not Good-King-Henry)
Maid Marian (not Maid-Marian)
St. John's-wort (not St.-John's-wort)
NOTE: Hyphens are also discouraged when separating proper names such as geographic place
names or when setting off directions (northern, eastern, southern, and western) from other associated
adjectives, e.g.
Blue Ridge gayfeather (not Blue-Ridge gayfeather)
eastern fringed catchfly (not eastern-fringed catchfly)
Great Plains bladderpod (not Great-Plains bladderpod)
Gulf Coast searocket (not Gulf-Coast searocket)
northern marsh yellowcress (not northern-marsh yellowcress)
southern Sierran pincushion (not southern-Sierran pincushion)
III. General Guidelines for Group Names
Group names should:
1. be as concise as possible;
2. never repeat the generic name except when steeped in tradition (e.g., aster, iris, mimosa);
3. reflect official state tree, shrub, and wildflower names when possible;
4. follow long-standing tradition;
5. follow names in popular use (e.g., field guides and conservation literature);
6. be unique for each genus. Understandably, this may not always be possible, e.g., when similar and
well-established group names exist for different genera, e.g.
Huperzia - club-moss
Lycopodiella - club-moss
7. reflect as much ethnobotanical heritage as possible, and commemorate aboriginal usage (e.g.,
pawpaw, a Native American name);
8. be easily understood by avoiding or minimizing the use of technical or unfamiliar terminology;
9. avoid the word "weed" for plant genera with rare species;
10. provide unique common names for well-defined subgenera or subgroups within genera; e.g.
Erythronium: white or pink flower - fawn-lily
yellow flower - trout-lily
Ribes: spineless plants - currant
spiny or thorny plants - gooseberry
NOTE: Occasional departure from the accepted group name is also encouraged in the case of more
fanciful, descriptive, or traditional common names, e.g.
camphor-daisy (for Machaeranthera phyllocephylla; departs from the group name tansy-aster)
dunedelion (for Malacothrix incana; departs from the group name desert-dandelion)
shieldplant (for Streptanthus tortuosus; departs from the group name jewelflower)
whip-poor-will-flower (for Trillium cernuum; departs from the group name wakerobin)
(Also see Section VI, Fanciful Phrases as Common Names)
11. be used in the possessive when using animal parts, e.g.
adder's-tongue bird’s-foot-trefoil
crane's-bill hound 's-tongue
ladies’-tresses mate's-tail
pheasant's-eye stork's-bill
12. when using animal names, group names should not be used in the possessive, and the policies
governing group names should be followed, e.g.
chickweed (not chick's-weed) dog-fennel (not dog's-fennel)
dog-mustard (not dog's-mustard) rat-apple (not rat's-apple)
thin-leaf owl-clover (not thin-leaf owl's-clover)
IV. Modifiers
Modifiers are used to establish uniqueness for the group name. Mostly adjectival, they are of four basic
types:
1. Those that provide description of plants or animal parts, size, shapes, colors, fragrances, number,
and textures, e.g.
hare-foot locoweed hay-scented fern
long-leaf pine sharp-keel milk-vetch
single-leaf pinyon red-seed plantain
2. Those that provide descriptions for plant habits or habitats, e.g.
annual hedge-nettle bottom-land post oak
coastal-plain mountain-mint granite stonecrop
vernal-pool snake-lily water-thyme
3. Those that commemorate individuals, e.g.
Douglas-fir Gray’s lily
Johnson grass Thieret’s skullcap
4. Those that describe geographic locations, e.g.
African basil Blue Ridge horsebalm
Caribbean hair-sedge Carolina hemlock
eastern white pine Ozark spiderwort
V. General Guidelines for Modifiers
The following guidelines apply to the use of modifiers.
1. Modifiers composed of two words should be used in the nominative rather than the adjectival form
(unless the modifiers are well established in usage, e.g., hay-scented fern), e.g.
broad-leaf lancepod (not broad-leaved lancepod)
little-tooth sedge (not little-toothed sedge)
long-leaf starwort (not long-leaved starwort)
slim-pod rush (not slim-podded rush)
tough-leaf dogwood (not tough-leaved dogwood)
2. Modifiers composed of one word should be used in the adjectival rather than the nominative form,
e.g.
bearded jewelflower (not beard jewelflower)
crested wheat grass (not crest wheat grass)
jeweled rocket (not jewel rocket)
rusty lupine (not rust lupine)
spotted lupine (not spot lupine)
tufted bulrush (not tuft bulrush)
3. Modifiers should be hyphenated when describing plant or animal parts, shapes, colors, sizes,
fragrances, or textures, except when referencing proper names (e.g., Ottertail Pass saxifrage), e.g.
bird-bill dayflower bird-eye speedwell
dog-tooth noseburn five-leaf cinquefoil
fox-tail prairie-clover shell-bark hickory
short-leaf cinquefoil hairy-seed crown grass
4. Modifiers describing color shades should be hyphenated, e.g.
midnight-blue clustervine
ocean-blue morning-glory
sky-blue scorpion-weed
5. When describing plant communities or plant habitats, two-word modifiers should be combined as
one when both words are single-syllable (unless the first and last letters of each word are the same,
e.g., sand-dune thistle), e.g.
oldfield milkvine pineland golden-aster
saltmarsh sandspurry seaside sedge
streambank leopard's-bane roadside raspberry
6. When describing plant communities or habitats, two-word modifiers should be hyphenated when
either word is composed of two or more syllables, e.g.
Arctic-tundra whitlow-grass coastal-plain dawnflower
cold-desert phlox river-bar bird’s-foot-trefoil
sandy-plain clustervine vernal-pool pincushion-plant
7. Independent, second-word modifiers should remain separated without a hyphen, e.g.
American water starwort (not American-water starwort)
dotted wild coffee (not dotted-wild coffee)
early blue violet (not early-blue violet)
leafless beaked ladies'-tresses (not leafless-beaked ladies'-tresses)
sticky purple crane's-bill (not sticky-purple crane’s-bill)
8. Independent, third-word modifiers should also remain separated without a hyphen, e.g.
lesser yellow-throat gily-flower (not lesser-yellow-throat gily-flower)
little red-stem monkey-flower (not little-red-stem monkey-flower)
9. When commemorating individuals, possessive modifiers should always be used (unless well
established in tradition e.g., Douglas-fir, Johnson grass), e.g.
Britton’s skullcap (not Britton skullcap)
Gray's lily (not Gray lily)
Hall's rush (not Hall rush)
Small's skullcap (not Small skullcap)
Ward’s willow (not Ward willow)
NOTE: When both the given name and the surname of an individual are used, a hyphen is not
required between the names, e.g.
Alice Eastwood's fleabane (not Alice-Eastwood's fleabane)
Carl Mason's ragwort (not Carl-Mason’s ragwort)
10. When describing plant or animal parts, modifiers (unlike group names) should not be used in the
possessive, e.g.
fox-tail prairie-clover (not fox's-tail prairie-clover)
cat-claw mimosa (not cat's-claw mimosa)
stag-horn fern (not stag's-horn fern)
11. When designating national subdivisions (i.e., states, counties, and provinces), nominative rather
than adjectival modifiers should be used, e.g.
Alaska-cedar Alberta spruce
Gila County live-forever New Mexico milkwort
Utah juniper Texasplume
12. When designating countries and continents, adjectival rather than nominative modifiers should be
used, e.g.
American spurred-gentian Brazilian peppertree
Canadian thistle European bellflower
Jamaican-broom Japanese honeysuckle
Mexican-orange Persian rye grass
13. When describing geographic direction, adjectival rather than nominative modifiers should be
used, e.g.
northern silverpuffs southern threeawn
eastern teaberry western sea-purslane
14. When selecting modifiers for related species, parallel structure should be sought, e.g.
broad-leaf sand-verbena narrow-leaf sand-verbena
false babystars true babystars
johnnynip johnnytuck
king-of-the-meadow queen-of-the-meadow
northern adder’s tongue southern adder’s-tongue
small-whorl mallow large-whorl mallow
15. For very wide-ranging species, use of local or provincial names should be avoided, e.g.
common St. John’s-wort (not Klamathweed, presumably a local name in the Pacific states)
common dandelion (not pee-da-bed, local name in northeastern U.S.)
lyre-leaf rockcress (not Kamchatka rockcress, local name in Pacific Northwest)
small cranberry (not wren's-egg cranberry, local name used mostly along the coast of Maine)
16. Modifiers should be concise, yet meaningfully descriptive, using the most colorful adjectives and
reflecting uniqueness of habitat, geography, toxic or medicinal properties, and flower morphology,
color, or fragrance.
17. When selecting modifiers, mere English translation of Latin or Greek epithets should be avoided.
Avoid surnames of individuals as modifiers because such modifiers provide very limited information
on properties, characteristics, and other features of a plant.
18. In selecting modifiers, the word "common" and other rather shallow descriptive adjectives should
similarly be avoided except when steeped in tradition (e.g., common dandelion).
VI. Fanciful Phrases as Common Names
Fanciful phrases composed of two or more words or elements as common names are encouraged. They
are often used as substitute names for group names, or they can be used as the accepted group names.
Such names should be governed by the guidelines established for group names. Phrase names,
especially lengthy ones, should be hyphenated between each word or element, e.g.
devil’s-darning-needles forget-me-not
herb-of-the-crown jack-in-the-pulpit
kiss-me-over-the-garden-gate love-in-a-mist
old-man-in-the-spring midnight-horror
NOTE: Fanciful phrases, however, should be limited to five or six words or elements, thus avoiding
excessively lengthy names such as welcome-home-husband-however-drunk-you-be.
VII. General Guidelines for Spelling
Consistency of spelling and form should be sought for both group names and modifiers. The following
suggestions are provided for words with alternate spellings or forms:
burr (not bur)
coastal (not coast)
county should be spelled out (not abbreviated as co.)
forked (not forking)
gray (not grey)
gypsum (not gyp)
mountain should be spelled out and singular (not abbreviated as mt., mts., mtn, or mtns.; however,
Mt. is preferred to Mount)
pygmy (not pigmy)
savannah (not savanna)
woolly (not wooly)
Allegheny for the mountain range (not Alleghany)
Great Smoky Mountain for the mountain range (not Smoky Mountain)
Guadalupe Mountain for the mountain range (not Guadeloupe)
Rocky Mountain for the mountain range (not Rocky Mountains)
Sierran for the mountain range (not Sierra nor Sierra Nevada)
Guadeloupe for the country (not Guadalupe)
Chihuahuan for the desert (not Chihuahua)
Mojave for the desert (not Mohave)
Sonoran for the desert (not Sonora)
St. (not Saint)
greater is preferred to larger
lesser is preferred to smaller
papery is preferred to membranaceous (and membranous)
pinewoods or pineland is preferred to pine
seaside is preferred to seabeach
VIII. General Guidelines for Capitalization
The following guidelines have been prepared to assist in the use of capitalization of proper nouns and
adjectives for common names.
1. Capitalize surnames of individuals used in group names and modifiers, e.g.
Bradbury-bush Douglas-fir
Engelmann’s flat sedge Gray’s lily
Johnson grass Klein’s evening-primrose
Nuttall’s oak Small’s ragwort
2. Capitalize names honoring nationalities and human races
Chinese hemlock-parsley Italian lords-and-ladies
Hopi-tea Norwegian whitlow-grass
New Zealand-flax Barbados aloe
3. Capitalize the names of gods, goddesses, and other religious figures, including names referring to
the deity or holy works
Adam-and-Eve Adam's-needle
Christmas-rose Crucifixion-vine
Easter-bonnet Joseph’s-coat
Hercules-club Heart-of-Jesus
Holy Ghost skyrocket Joshua-tree
Our-Lord's-candle Venus’ flytrap
4. Capitalize names suggesting titles, canonizations, and ranks of honor, e.g.
Aunt Lucy St. Catherine's-lace
Queen Ann's-lace St. John's-wort
NOTE: Capitalization should not be used when specific reference to an individual is not provided, e.g.
king orchid kingdevil
madam-gorgon princess-of-the-night
princesstree queen spleenwort
5. Capitalize international and national place names and national subdivisions such as continents,
countries, states, counties, parishes, provinces, and territories e.g.
American holly Asian sword fern
European mountain-ash Florida bear-grass
Ohio buckeye New York fern
Shasta County leopardbane Yukon lupine
6. Capitalize local place names, including the names of cities, parks, and other recreational areas,
e.g.
Everglades palm Grand Canyon glow-weed
San Diego bear-grass Santa Fe phlox
Yosemite woolly-sunflower Yellowstone rockcress
7. Capitalize geographic directions only when they designate specific areas or regions, e.g.
East Indian holly fern North Pacific whitlow-grass
North African knapweed South American saltbush
NOTE: Mere directional adjectives should not be capitalized, e.g.
northern birch southern cat-tail
western Australian flooded gum western sand-parsley
8. Capitalize modifiers that comprise part of a proper name and are written in the singular, such as:
bay basin
butte canyon
cape county
creek delta
desert flat
gap glacier
gulf harbor
head island
lake Mt.
mountain ocean
pass peak
peninsula plain
plateau point
range ridge
river sea
straight valley
Examples of these modifiers include:
Blue Ridge bittercress Cape Thompson whitlow-grass
Grant's Pass willowherb Great Basin tumble-mustard
Mt. Lassen fairyfan Rocky Mountain bluebells
Syes Butte plains-mustard Wind River tansy-mustard
IX. True Group Names
The following genera and plant groups are listed with their "true group" names. All other genera
referencing these common names should be considered misapplied.
Abies - fir
Abutilon - velvetleaf
Achillea - yarrow
Achyranthes - chaff-flower
Actaea - bugbane
Aesculus - buckeye
Ageratina - snakeroot
Agropyron - wheat grass
Alisma - water-plantain
Allium - garlic, leek, onion
Alnus - alder
Alocasia - taro
Aloe - aloe
Amaranthus - pigweed, tumbleweed
Anchusa - bugloss
Andropogon - bluestem, broom grass
Antirrhinum - snapdragon
Apocynum - dogbane
Arachis - peanut
Arctostaphylos - manzanita
Aristolochia - birthwort, Dutchman's-pipe
Aster - aster
Bambuseae - bamboo
Brandegea - starvine
Brassica - cabbage, mustard, rape
Brickellia - brickellbush
bryophyte - moss
Buxus - box
Calluna - heather
Camassia - camas
Campanula - bellflower
Capparis - caper
Capsicum - pepper
Carex - sedge
Carum - caraway
Castanea - chestnut
Cedrus - cedar
Chrysolepis - chinkapin
Cichorium - chicory
Cinnamomum - cinnamon
Cirsium - thistle
Cissus - treebine
Citrus - orange, lemon, lime
Convolvulus - bindweed
Corallorrhiza - coralroot
Corchorus - jute
Corylus - hazel
Croton - croton
Cucumis - cucumber, melon
Cucurbita - pumpkin, squash
Cupressus - cypress
Cydista - withe
Cydonia - quince
Cynara - artichoke
Cytisus - broom
Dianthus - pink
Digitalis - foxglove
Diodia - buttonweed
Dioscorea - yam
Dodecahema - spinyherb
Dracocephalum - dragonhead
Drypetes - rosewood
Elymus - wild rye
Epilobium - fireweed, willowherb
Erica - heath
Eucalyptus - gum
Eugenia - stopper
Euphorbia - spurge
Fagopyrum - buckwheat
Fendlera - Fendlerbush
Ficus - fig
Foeniculum - fennel
Fragaria - strawberry
Fraxinus - ash
Gaylussacia - huckleberry
Gentiana - gentian
Geum - avens
Gnaphalium - cudweed
Gossypium - cotton
Helianthus - sunflower
Helleborus - hellebore
Hemizonia - tarweed
Houstonia - bluet
Humulus - hop
Hyacinthus - hyacinth
Hyssopus - hyssop
Ilex - holly
Indigofera - indigo
Ipomoea - morning-glory
Isoetes - quillwort
Jasminum - jasmine
Juglans - walnut
Juncus - rush
Lactuca - lettuce
Lagerstroemia - crape-myrtle
Laurus - laurel
Lavandula - lavender
Levisticum - lovage
Ligustrum - privet
Lilium - lily
Linaria - toadflax
Linum - flax
Liriodendron - tuliptree
Lithospermum - gromwell
Loeseliastrum - calico
Lomatium - desert-parsley
Lonicera - honeysuckle
Lychnis - campion
Lythrum - loosestrife
Malus - apple
Malva - mallow
Marrubium - horehound
Matthiola - stock
Mentha - mint
Mercurialis - mercury
Mesembryanthemum - iceplant
Mimulus - monkey-flower
Mirabilis - four-o'clock
Morus - mulberry
Musa - banana
Myosotis - forget-me-not
Myrrhis - anise
Myrtus - myrtle
Nelumbo - lotus
Nicotiana - tobacco
Obolaria - pennywort
Ocimum - basil
Olea - olive
Oryza - rice
Paeonia - peony
Panicum - millet, panic grass
Papaver - poppy
Pastinaca - parsnip
Penstemon - beardtongue
Petroselinum - parsley
Phaseolus - bean
Phoradendron - mistletoe
Phragmites - reed
Pimenta - allspice
Pinguicula - butterwort
Pinus - pine
Plantago - plantain
Polygala - milkwort
Pontederia - pickerelweed
Portulaca - purslane
Potamogeton - pondweed
Primula - primrose
Proboscidea - unicorn-plant
Prunus - almond, cherry, peach, plum
Psidium - guava
Pyrola - wintergreen
Pyrus - pear
Quercus - oak
Ranunculus - buttercup
Raphanus - radish
Rhamnus - buckthorn
Rheum - rhubarb
Rhus - sumac
Ribes - currant, gooseberry
Robinia - locust
Rosa - rose
Rosmarinus - rosemary
Rubia - madder
Rudbeckia - coneflower
Rumex - sorrel
Ruta - rue
Sabal - palmetto
Salix - willow
Salvia - sage
Sambucus - elder
Santalum - sandalwood
Sarcodes - snowplant
Satureja - savory
Saxifraga - saxifrage
Scirpus - bulrush
Scrophularia - figwort
Scutellaria - skullcap
Sedum - stonecrop
Selinocarpus - moonpod
Sequoia - redwood
Sideritis - ironwort
Solanum - nightshade
Solidago - goldenrod
Spinacia - spinach
Sullivantia - coolwort
Swertia - felwort
Swietenia - mahogany
Symphoricarpos - snowberry
Symphytum - comfrey
Symplocarpus - skunk-cabbage
Tagetes - marigold
Talinum - fameflower
Tamarindus - tamarind
Tanacetum - tansy
Taraxacum - dandelion
Teucrium - germander
Thalictrum - meadow-rue
Thuja - arborvitae
Thymus - thyme
Tillandsia - airplant
Tragopogon - salsify
Trichostema - bluecurls
Trifolium - clover
Tsuga - hemlock
Tussilago - colt's-foot
Ulmus - elm
Urtica - nettle
Vallisneria - eel-grass
Verbascum - mullein
Verbena - vervain
Vicia - vetch
Vinca - periwinkle
Viola - violet
Vitis - grape
Wolffia - watermeal
Zea - corn
Zingiber - ginger
All genera of the following plant families (or major plant groups) represent true types; thus, their group
names should not be hyphenated:
Arecaceae - all names referencing palm
Cactaceae - all names referencing cactus
Cucurbitaceae - all names referencing gourd
Cyperaceae - all names referencing sedge
Orchidaceae - all names referencing orchid
Poaceae - all names referencing grass
Pteridophytes - all names referencing fern and "fern-allies"
The following words are of indeterminate application, not representing true groups, and thus can be
used in various group names or fanciful phrases:
balm balsam
bay briar
creeper cress
daisy flag
haw hedge
ivy mampoo
mangrove osier
rocket rodwood
