This guide is intended to assist federal and state
personnel, and other interested parties, in the identification of Alaska's
rare vascular plants. Preserving the diversity of our plant and animal life-
our biodiversity- is a growing public concern and is recognized as a goal
in the management of federal and state lands. Rare plants are a basic part
of this biodiversity, important not only for their own value, but as indicators
of unusual or rare communities and natural habitats. Areas with rare plants
may be centers of high biodiversity, or they may be refugial areas where
species survived the last ice age and the rare ones remain restricted today.
The passage of the Endangered Species Act (ESA) in 1973 spurred interest
in the conservation of rare plants and led to the adoption of policies and
regulations designed to ensure their survival. The success of these conservation
efforts depends upon our knowledge of these plants and our ability to recognize
them in the field. Most of Alaska is administered by federal and state agencies
and much of it is still poorly known botanically. As development in remote
areas continues there is an increasing need to conduct surveys for rare
species and to define their distribution and status. Knowing about the presence
of rare species ahead of time allows development projects to be planned
so as to minimize disturbance to those populations and also reduces delays
during the regulatory and environmental review process. This manual provides
current information on the identification, distribution, and habitat of
Alaska's rare vascular plant species.
It has been ten years since the publication of the last guide to Alaskan
rare plants (Murray and Lipkin 1987) and the need for an updated version
has become increasingly evident. Federal policies concerning rare plants
have changed, and we have seen a great increase in our knowledge of the
distribution, abundance, and basic biology of these species. New species
have been discovered- some new to Alaska, and some entirely new to science.
Species previously thought rare are now known to be more widespread and
are no longer of serious conservation concern. Other taxa that were once
designated as Candidates for listing as Threatened or Endangered species
are no longer considered taxonomically valid and are now subsumed by other
more common species. Information from intensive field work by biologists
from universities, federal and state agencies, and consulting firms, as
well as by interested amateurs, has greatly refined our ability to define
the habitats of many rare species.
There have been several important changes in federal policy since the 1987
guide was published. Many of the species in that guide were listed by the
U.S. Fish and Wildlife Service as Category 2 candidates. This category included
taxa which may have warranted protection under the ESA but for
which we lacked adequate data to fully support formal proposals for listing.
These taxa required additonal field work to better define their distribution,
abundance and stability. The Fish and Wildlife Service discontinued the
designation of Category 2 species as candidates in 1996. It now relies on
other information sources (including state lists of rare and endangered
species, and state Natural Heritage Program databases, and The Nature Conservancy's
Biological and Conservation Data System) to identify those species that
may be imperiled or vulnerable. There remains one plant species listed as
Endangered (Polystichum aleuticum), but there are no candidate plant
species in Alaska at this time. Taxa in this guide that were Category 2
candidates when that designation was discontinued include: Artemisia
globularia var. lutea, Botrychium ascendens, Cryptantha shackletteana,
Douglasia beringensis, Draba murrayi, Eriogonum flavum var. aquilinum,
Mertensia drummondii, Oxytropis arctica var. barnebyana, Podistera
yukonensis, Rumex krausei, and Smelowskia pyriformis.
A second important change occurred in 1994 when, for the first time, the
Forest Service adopted a list of Sensitive Plant Species for the Alaska
Region. Several of these species are described in this guide and are listed
in the "Alaska Rare Plant Species List" in the first section of
this guide.
We have assumed the reader has a basic familiarity with the major plant
groups and we have described the species as simply as possible. A glossary
of technical terms is included. This guide is intended to supplement, not
replace, the more comprehensive treatments of Alaska's flora such as Hultén
(1968) or Welsh (1974) and will be of greatest use to those with at least
some knowledge of botany. The first section of this guide contains a list
of the rare plants, their federal status (if any), their ranking by the
Alaska Natural Heritage Program and The Nature Conservancy (TNC), and the
management status of the lands on which they are found. The various federal,
international, and Heritage Program categories are defined under "Definitions
and Codes", below. The remainder of the guide contains descriptions
of the rare species arranged alphabetically. For each we have included a
line drawing of diagnostic field characters, photographs (when available)
of the plant and its habitat, and text distinguishing each species from
similar ones with which it might be confused. Additional information can
be found in the references cited, which are listed in abbreviated form under
each species account. A full citation can be found in the References section.
Habitats are described when they are known, but our knowledge of some rare
species is based solely on a few herbarium specimens, and ecological notes
on specimen labels are brief and can be ambiguous. The distribution of each
taxon is generalized in the text, and a map is included on which all Alaskan
localities are included, although a single dot can represent one or several
neighboring sites.
When the specific habitat can be described in detail,
this knowledge can be used to predict where else the plant might be found.
This allows us to narrow the field of view when searching for new records,
but we cannot make the assumption that the plant, in all cases, will be
found there. First, our perception of the precise environmental controls
is likely to be imperfect, and we may mistakenly attribute significance
to a particular habitat type. Second, plants do not occupy all the places
that are suitable for them. Therefore, field checks are requred to test
our predictions. Nevertheless, even with the meager habitat and geographic
data at hand, we can make educated guesses. The critical habitats are usually
not in the common widespread types, but in more specialized settings, often
different from the surorunding terrain. Many of the plants treated in this
manual show affinities for dry bluffs, flood plains, river terraces, sand
dunes, rocky slopes, outcrops, fellfields, and mountain summits. These settings
are also the sources for ballast and fill required by construction projects,
and in the Far North on ice-rich soils, the volumes used can be enormous.
The implications should be obvious.
Rarity is a relative term and can be defined in many ways. Practical constraints
of space compelled us to limit this guide to those taxa that are not only
rare in Alaska but limited in their world-wide distribution as well.
These include our narrowly endemic species, which
may be known from only a few sites clustered in a small portion of the state,
as well as some regional endemics that are also known from adjacent areas
in Canada and Russia. Some of these regional endemics are more common in
these adjacent areas, but in no case do they have a Global Rank higher than
G3 (see Definitions and Codes). Most are ranked G1 or G2 (or T1 or T2) and
are generally known from fewer than twenty locations. Those species ranked
G3 are known from fewer than fifty locations world-wide and restricted in
Alaska to fewer than twenty locations. The G3 criteria allowed us to include
most of the species of federal concern. A number of the Forest Service species
designated as Sensitive in Alaska were excluded because they were regional
endemics that we felt to be secure worldwide.
It is our hope that this book will encourage botanical exploration leading
to new information and new locations for these taxa. Some will prove to
be more common, new species will be described and new records will be found
for taxa not previously known from Alaska. We fully expect this guide to
become outdated as additional areas are surveyed, and the three-ring binder
format will allow for species to be added, deleted or revised.
The Alaska Natural Heritage Program (AKNHP) of the University of Alaska, Anchorage serves as a repository for information on rare species and communities in Alaska and maintains this information in their Biological Conservation Database. The Herbarium of the University of Alaska Museum is the principal botanical collection in the state and maintains permanent physical documentation and records on plant distributions and taxonomy. New locations for rare plants should be reported to either the Heritage Program or the Herbarium and collections should be archived at the Herbarium. All collections and reports should include detailed notes on location, habitat, and abundance.
Whereas specimens are required to document a new locality and are useful in support of research on our rare plants, do not make collections unless you are certain the removal of a few plants will not significantly reduce the population. If there is any question, do not collect but take a photographic record and make detailed notes. Be certain to describe the site so it can be relocated. Also be aware that permits are required for collecting in parks and other protected areas as well as on native corporation and other private lands.