Format
The
following entries are arranged in alphabetical order by the scientific name of
the major botanicals treated. (Some botanicals are treated only as secondary
topics or contaminants, and can be located in the index.) Some explanatory
notes on the content of the entries should be provided first.
Common
names
The
AHPA-selected Standardized Common Names and other frequently encountered common
names are provided under the title of each entry. For the most part, only English
common names are given. The exceptions are for non-Western botanicals whose
vernacular common names are frequently used in herbal literature.
Family
Just
as related species are grouped into genera, related genera are grouped into
families, which often share unique combinations of characters that enable their
quick recognition. Getting to know these families is one of the keys to easy
plant identification. In modern taxonomic practice, a family is named for one
of the included genera, and has the ending -aceae. For example, the daisy
family (Asteraceae) is named for Aster.
Older family names did not always follow this pattern, and eight of the largest
and most economically important plant families have accepted alternate names
that have been conserved because they are so common in the literature. For
example, Asteraceae may also be called Compositae. These names are included in
parentheses. Sometimes there has been a difference or change of taxonomic
opinion about what genera should be included in a particular family; all of the
common opinions are given as alternatives here. Family names are not italicized
in American practice, although they often are in Europe.
Taxonomy
The
approximate size and distribution of the genus to which each plant belongs is given.
On occasion, the infrageneric classification is mentioned as well. A large and
complex genus may be divided into subgenera, sections, and/or series. If
multiple levels of division are used, a subgenus outranks a section, so that
one subgenus might contain multiple sections, and a section outranks a series. If
the plant is part of a taxonomically difficult species complex, so that species
boundaries are not certain, or if hybridization among species is frequent,
these facts are noted. Many variable species have been divided into subspecies
or varieties, which are often of little practical use; these are mentioned only
when they reflect significant taxonomic distinctions. Important synonyms that
might be encountered in literature are listed. Some plants have dozens of
synonyms that are never used at all; these are omitted. Where more than one
species may be used interchangeably, the situation is discussed.
Description
A
brief botanical description of the whole plant is provided for purposes of
general information and to assist those who wish to confirm the identity of
aboveground parts (or pressed voucher specimens made from those parts) or,
perhaps, living material as it is harvested. Jargon has been minimized, but the
glossary in the back defines unavoidable terms. Measurements or variation in
number of parts are given in metric as ranges, e.g., “5–8 cm long” or “stamens
4–5.” Likewise, “2–3-pinnately compound” describes a leaf that may have either
two or three orders of division. A common practice in taxonomic literature is
to set the extremes of a range aside in parentheses, e.g., “(3–)5–8(–15) cm
long” means that the plant part is usually 5–8 cm long, but rarely may be as
short as 3 cm or as long as 15 cm. Figures for stem height, leaf length, etc.
in taxonomic literature refer only to mature plant parts: in many plants,
younger leaves are present in a complete size range, down to very tiny, so the
presence of some small leaves is not suspicious, whereas that of very large
leaves would be. Descriptions are derived from published scientific literature
(including floras, revisions, and monographs) and herbarium specimens, but are
not intended to be exhaustive. It should be remembered that probably no
description ever published has completely encompassed all the possible
variation in a species, because “the plants haven’t read the book!”
Parts
in commerce
The
listed parts are those that are most commonly used and that seemed most
amenable to treatment in this text. These choices do not imply that other parts
may not also be used, even frequently. For example, grape seed is described but
whole grapes are omitted, not because they are rarely used, but because
everyone knows exactly what they look like.
Identification
The
bulleted lists provided focus on key features of the parts in question,
expanding upon the botanical description and using the simplest possible
language. The intention is to separate the complex description of a plant into
a list of simpler features that can be checked one by one. Both positive
characters (those which should be present) and negative characters (those which
should not be present in correctly identified material) may be noted. Sensory
or organoleptic characters (e.g., taste and odor) are also listed, as these are
often very important, although people vary in their ability to discern
different tastes and smells. Other such characters include texture and (for
roots and barks) the fracture, or how hard a dried piece is and how it breaks,
which was an important character in traditional pharmacognostic descriptions. The
language used in that literature to describe fracturing is diverse and perhaps
rather subjective, but there is a palpable and visible difference between a
hard, short fracture and a very fibrous fracture or a brittle fracture. Tasting,
smelling, feeling and breaking as many plant samples as possible will help to
develop the ability to perceive subtle differences among botanicals. Although
lab tests requiring expensive or restricted reagents have not been discussed in
this manual, there are a few very simple chemical tests which may enhance one’s
confidence in the identity of certain botanicals. These have been mentioned
briefly under the relevant entries.
Adulterants
Certain
species have been reported in pharmacognostic literature to be inappropriately
present in material that was sold as some other species. This can be the result
of accidental substitution (in which the wrong plant is mistakenly identified
as the correct one, or believed to be interchangeable with it), accidental
contamination (in which some admixture of the wrong plant is harvested along
with the correct one), or fraud (in which a cheaper plant is deliberately
substituted for or mixed with the correct species). Adulteration can also
involve the use of improper plant parts of the correct species, for example,
the inclusion of many large stems in a product supposed to be made from leaves
only. In common speech, “adulteration” implies the deliberate manufacture of
low-quality products. In the botanical industry, “adulteration” is used
generically to refer to any inclusion of incorrect plant species or plant parts
in excessive quantity, whether deliberately or by accident. It is used here in
that sense, so no imputation of motives is implied or should be assumed: most
reported adulteration is unintentional. Related species of commercial
importance may also be discussed in or around this section even if they are not
known to be adulterants of the primary species. Means of distinguishing
wild-collected plants from relatives found in similar habitats may be
mentioned; again, this does not necessarily indicate that adulteration with
those relatives has been reported to be a problem in practice, only that it
could be possible.
References
References
used in compiling each entry are cited at the end of that entry. These
frequently contain further information, omitted here, that might be valuable to
those interested in a specific plant. Several major pharmacognostic or
botanical references that were used frequently, together with some general
references useful for such subjects as nomenclature or anatomy, are
additionally listed in the reference section at the back of the manual.
Figures
To
aid the reader in interpreting descriptions, botanical illustrations are provided
for many plants. Multipart figures occasionally include illustrations of a
particularly important adulterant or relative as well as the primary species,
so check the caption!
Please
note that in some botanical entries the order of these sections may be changed
in order to allow the identification information to remain in close proximity
to the corresponding figure.
