Rarity of Organisms in the
Sand Pine Scrub Habitat
of Florida
EARL D. M c C O Y
HENRY R. MUSHINSKY
D e p a r t m e n t o f Biology a n d C e n t e r for U r b a n Ecology
University o f South Florida
Tampa, FL 33620, U.S.A.
Abstracta Naturalists conceive o f "rare" organisms as those
narrow in geographic range restricted to f e w habitat~ or
small in population stze~ Because rare organisms may be
rare in a variety o f way~ a particular conservation strategy
that purports to protect them may not do so effectively in all
cases; therefore, categorization o f rarity in advance could
help ensure that the chosen strategy has a reasonable chance
o f success in a particular case. We placed plant~ amphibian~ and reptiles resident in the Sand Pine scrub habitat o f
Florida into categories o f rarity. Determining i f and in what
way a particular organism is rare proved difficulg because
the process requires exact specification o f what is meant by
"'narrow, " "restrictea~ " and "small ""F u r t h e r m o ~ the process
requires choice o f a scale f o r judging rarity and relies upon
data that are likely to be o f variable availability and reliability. We categorized rarity by several scheme~ and they
produced distributions o f taxa among categories o f rarity
that largely were similar to one another but that diverged in
telling ways. The distributions o f taxa among categories o f
rarity produced by a n y scheme were different f o r scrub
plants than f o r scrub amphibians and reptile~ Likewise,
these distributions were different than those produced by
previously published studies o f rarity. We f o u n d that the
results o f our categorization schemes did not match particularly well with the official listing o f scrub organisms as
endangered or potentially endangered.
Paper submittedJm~ 14, 1990; revised manuscript accepted November 2L 1991.
Address correspondence to £ D. McCoy.
Rareza d e los organismos e n u n l ~ b i t a t a r e n o s o d e pinares
e n a n o s e n La Florida
R e s u m e n : Los naturalistas conciben a los organismos
"'raros,'" como aquellos que tienen u n reducido rango
geogrdfico, o e s ~ n restringldos a pocos bd~itat~ o tienen
tamatios poblacionales pequehos. Dado que organismos
raros lo son en una variedad de formag una estrategla de
conservaci6n particular que tenga como prop6sisto proteger
organismos raros podrta no resultar efectit~a en todos los
caso~, p o t consiguient¢ una categortzaci6n de rareza p o r
adelantado puede ayudar a asegurar que la estrategia
elegida tenga una posibilidad de #2cito rasonable en un caso
determinado. Nosotros clasificamos en tdrminos de rareztg
plantas, anfibios y reptiles residentes en en a m b i e n t e
arenoso de pinares enano~ en la Florida El determinar si un
organismo particular es raro y en que sentldo 1o e& demostr6
ser dificil porque el proceso requiem una exacta especificaci6n de que se entiende p o t "reducido, ....restringido" y "'pequetio." Mds at~rg el proceso requiem la elecciOn de una
escala para j u z g a r rareza~ y se apoya en datos que probablemente sean de una disponihilidad y confiabilidad variable~ Nosotros categorizamos rareza segt~n diferentes esquemas y estos p r o d u j e r o n distribuciones de t a x o n e s en
categorias de rareza que fueron bastante similare~ pero difirieron unas de otras en f o r m a esclarecedorat La distrtbuci6n de taxones entre las distintas categorlas de rareza pro.
ducida p o r cualquier esquema f u e r o n diferentes entre
plantas del monte bajo y anfibios y reptiles del monte bajo.
En f o r m a semejant~ estas distrthuciones fueron diferentes de
aquellas producidas p o r estudios de rareza previamente
publicado£ Nosotros encontramos que los resultados de
nuestro esquema de categorizaci6n no coincidi6 particularmente bien con la lista oficial de organismos del monte bajo
en peligro o potencialmente en peiigro de extinci6ri
537
Conservation Biology
Volume 6, No. 4, December 1992
538
R~ty of FloridaScrub Organisms
McCoy& Mushinsky
Introduction
Rabinowitz et al. (1986; see also Rabinowitz 1981)
noted that naturalists conceive of "rarity" in several
ways. Rare organisms m a y o c c u r in only a few habitats,
they may be very localized in geographic distribution,
or they may be represented by few individuals. To clarify the different possible conceptions of rarity, Rabinowitz et al. ( 1 9 8 6 ) erected dichotomies of geographic
range ( " w h e t h e r a species occurs over a broad area or
w h e t h e r it is endemic to a particular small area," p.
183), habitat specificity ("the degree to which a species
occurs in a variety of habitats or is restricted to one or
a few specialized sites," p. 183), and local population
size ( " w h e t h e r a species is found in large populations
s o m e w h e r e within its range or has small populations
w h e r e v e r it is found," p. 183). These three dichotomies,
i n a l l their possible combinations, yield seven forms of
rarity and one form of c o m m o n n e s s (Table 1).
Rabinowitz et al. ( 1 9 8 6 ) n o t e d that recognizing
which form of rarity a particular rare species displays is
important in deciding h o w best to protect that species
from extinction. For example, a plant species with a
wide geographic range and large local population sizes
that is restricted to a single habitat ( t y p e 6 rarity in
Table 1) is not likely to benefit from transplants as a
m e t h o d of conservation. On the other hand, a plant species with a narrow geographic range and large local
populations in a broad range of habitats (type 4 rarity in
Table 1) may benefit from transplants. Rabinowitz et al.
(1986; see also May 1988) suggested that understanding
h o w species are apportioned a m o n g forms of rarity may
provide useful d u e s to understanding why certain species are in greater danger of extinction than others.
Table 1. Seven forms of rarity and one form of commonness,
derived by combining traits of geographic distribution, habitat
specificity, and local population size (after Rabinowitz et al.
1986, Table 1).
Geographic
distribution
Habitat
specificity
1
Narrow
Restricted
2
Narrow
Restricted
3
Narrow
Broad
4
Narrow
Broad
5
Wide
Restricted
6
Wide
Restricted
7
Wide
Broad
Commonness
8
Wide
Broad
Rarity
ConservationBiology
Volume6, No. 4, December1992
Local
population
size
Everywhere
small
Somewhere
large
Everywhere
small
Somewhere
large
Everywhere
small
Somewhere
large
Everywhere
small
Somewhere
large
We use the categorization of rarity and c o m m o n n e s s
developed by Rabinowitz et al. ( 1 9 8 6 ) to examine the
status of some organisms resident in the Sand Pine scrub
habitat of peninsular Florida. We place characteristic
plants, amphibians, and reptiles into the categories
listed in Table 1, and note w h i c h of the taxa (species or
subspecies) axe listed as endangered or potentially endangered (see W o o d 1988). We then determine if listed
taxa are disproportionately represented in any of the
categories, and h o w m u c h the suite of listed taxa overlaps with the suite of "rare" taxa. Finally, w e c o m m e n t
on the significance of our results for conservation of the
Sand Pine scrub habitat.
Methods
The Sand Pine Scrub Habitat
Sand Pine scrub habitat may be distinguished by a combination of three attributes: a substrate of old dunes
c o m p o s e d of deep fine white sands, rare fires (about
every 3 0 - 6 0 years), and xeric plants, often with subtropical affinities, including Sand Pine (Ptnus clausa),
and/or scrub oaks (Quercus chapmani6 Q. geminata~
Q. myrtifolia ), and/or Rosemary ( C e r a t i o l a ericotdes)
and Cladonia spp. (see Myers 1990). The habitat occurs, or formerly occurred, along the east coast of Florida from St. John's County in the north to Dade County
in the south, along the northern Gulf Coast from Mobile
Bay, Alabama, in the w e s t to Franklin County in the east,
and along the west coast of Florida from Levy County in
the north to Collier County in the south (Davis 1943,
1967). Scrub habitat also occurs, or formerly occurred,
throughout m u c h of the interior of the Florida peninsula, along ancient ridges. Decades of d e v e l o p m e n t have
reduced scrub habitat in Florida by m o r e than 60%
( P e r o n i & A b r a h a m s o n 1985a, 1985b; C h r i s t m a n
1988).
Despite its xeric nature, which makes it seem inhospitable to humans, the Sand Pine scrub habitat contains
a diverse array of organisms. About three hundred nonw e e d y species of plants~are k n o w n to o c c u r in Florida
scrubs (Richardson 1989), of which s o m e forty species
or subspecies are listed as endangered or potentially
endangered by W o o d (1988). Deyrup ( 1 9 8 9 ) listed
forty-six species of arthropods that are restricted to
scrubs in Florida. About seventy species of vertebrates
have b e e n c o l l e c t e d regularly f r o m Florida s c r u b s
(Richardson 1989), of which about a dozen species or
subspecies are listed as endangered or potentially endangered by W o o d (1988).
Characteristic Plants, Amphibians, and Reptiles
Tabulations of plants (including lichens), amphibians,
and reptiles characteristic of the Sand Pine scrub habitat
of peninsular Florida w e r e taken directly from Christ-
McCoy&Mushinsk£
man (1988). We added eight plant taxa that he did not
include as "characteristic" but instead called "restricted
to scrub." We note that a few other taxa might b e considered characteristic but w e r e not designated as such
by Christman (1988). For example, w e think Cladonia
perforata (see Buckley & Hendrickson 1988), and Crotolaria avonensis (see Delaney & Wunderlin 1989)
could be called characteristic. While "characteristic" is
given no explicit meaning by Christman (1988), w e infer that he intended the t e r m to mean taxa that o c c u r
disproportionately in the Sand Pine scrub habitat relative to other habitats. Thus, the use of these taxa in our
analysis excludes accidental residents ("transients") of
the scrub without omitting infrequently encountered
true residents.
Plants, amphibians, and reptiles w e r e chosen for use
in our analysis for several reasons. First, the natural histories of most invertebrates resident in Florida scrubs
are too poorly k n o w n to allow us to use t h e m (see
Deyrup 1989); thus, w e w e r e limited immediately to
plants and vertebrates. Among the terrestrial vertebrates
( n o fish reside in the sand pine scrub habitat), amphibians and reptiles (with the exception of large snakes)
are the most "plant-like," in that they are likely to have
m o r e trouble dispersing a m o n g patches of habitat than
birds or mammals. Relatively p o o r dispersal abilities
may translate into relatively high potential risks of extinction; therefore, plants, amphibians, and reptiles may
be the major focus of future efforts to conserve remaining patches of Sand Pine scrub habitat in peninsular Florida. One indication that taxa within these three groups
are most at risk is that they account for virtually all of
the endangered or potentially endangered organisms to
be found in peninsular Florida scrubs ( W o o d 1988);
c o n s p i c u o u s e x c e p t i o n s are the Florida Scrub Jay,
Aphelocoma ~ coerulescens and the Florida Mouse,
Podomys floridanu~
Categorization
Rabinowitz et al. ( 1 9 8 6 ) acknowledged that apportioning taxa a m o n g categories of rarity and c o m m o n n e s s is
not an easy task. One difficulty is the biases and preconceptions about rarity. Another difficulty is the fuzzy distinction b e t w e e n narrow and wide geographic ranges,
broad and restricted habitat specificities, and local pop.
ulation sizes that are s o m e w h e r e large and everywhere
small. These distinctions are fuzzy because the categories are relative. Yet another difficulty is that all types of
data are not equally available or reliable. Data on geographic range, for example, are likely to be better than
those on habitat specificity or local population size,
both because they are easier to obtain and because they
require fewer apriori assumptions (in the case of habitat specificity, the assumption that discrete habitats can
be recognized, and in the case of local population sizes,
Rarityof FloridaScrub O ~
539
the assumption that population sizes can be estimated
properly). A final difficulty is that a scale of examination
needs to be decided u p o n in advance, because the judgments that are made about rarity and c o m m o n n e s s are
likely to be influenced by the scale chosen. For example,
the geographic range of a British plant could be judged
by the extent of its distribution within Britain, within
Europe, or world-wide. To address these difficulties,
Rabinowitz et al. ( 1 9 8 6 ) used the educated opinions of
a panel of fifteen judges to apportion 177 British plants
among categories of rarity and commonness, a system
that they decided p r o d u c e d unambiguous results for
160 of the 177 species.
We also addressed as m a n y of these difficulties as w e
t h o u g h t possible in d e v e l o p i n g o u r c a t e g o r i z a t i o n
scheme for scrub plants, amphibians, and reptiles. To
remove our o w n biases and preconceptions about rarity, w e employed only previously published information
on geographic range, habitat specificity, and local population size. We made the categories absolute rather
than relative by setting their boundaries in advance (details axe provided below). We also decided that the scale
of examination should be large; that is, geographic
range, habitat specificity, and local population size all
w e r e judged over the entirety of each taxon's range.
This scale strikes us as the one that most p e o p l e implicitly use to designate taxa rare or c o m m o n , although
other scales may be u s e d - - f o r e x a m p l e - - t o place species on lists of endangered or potentially endangered
taxa (see below). We could think of no reasonable way
to compensate for inherent differences in reliability of
the various kinds of data.
Information on geographic distribution, habitat specificity, and local population size w e r e gathered from
several sources: Small (1933), Fink (1935), Fernald
(1950), Breen (1963), T h o m p s o n (1967), Long and
Lakela (1971), Wunderlin ( 1 9 8 2 ) and Christman and
Judd (1990), for plants; and Conant ( 1 9 7 5 ) and Ashton
and Ashton (1981, 1985, 1988) for amphibians and reptries. Geographic range was categorized as "narrow" if a
taxon is found only in Florida or "wide" if it is also found
outside Florida (recall that the scrub habitat is virtually
unique to Florida). Habitat specificity was d e t e r m i n e d
by d e t e r m i n i n g the distributions of taxa o v e r the
t w e n t y - o n e h a b i t a t s listed b y A s h t o n and A s h t o n
(1981). These habitat types are pine flatwoods; Sand
Pine-Rosemary scrub; Longleaf Pine-Turkey Oak; xeric
oak hammock; mesic hammock; hydric hammock; tropical hammock; t e m p e r a t e deciduous forest; farmland,
fields, and disturbed areas; h u m a n habitations, golf
courses, and trash piles; coastal beaches and dunes; salt
marsh; mangrove swamp; freshwater marsh; t e m p o r a r y
ponds and roadside ditches; cypress swamp and domes;
g u m swamp and river swamp; rivers; small streams and
creeks; and canals. Habitat specificity was categorized as
"restricted" if a taxon occupies less than the median
Conservation Biology
Volume 6, No. 4, December 1992
540
R,~ri~of FloridaScrubO ~ s m s
number of habitats for all taxa or "broad" if it occupies
more. The median n u m b e r of habitats occupied by plant
taxa is two and by amphibian and reptile taxa is seven.
Local population size was categorized as "everywhere
small" if a taxon has been designated "rare" (or an
equivalent t e r m ) or "somewhere large" if it has been
designated " u n c o m m o n " or " c o m m o n " (or equivalent
terms). We shall refer to this set of criteria as Scheme I.
We were concerned that our way of separating local
population sizes of scrub plants and amphibians and reptiles that are e v e r y w h e r e small from those that are
somewhere large might be unduly draconian under
Scheme I. Therefore, we created another categorization
scheme, Scheme II, by shifting taxa designated "uncommon" (or an equivalent term) from categorization as
somewhere large to categorization as everywhere small.
We created yet another categorization scheme, Scheme
III, for amphibians and reptiles. We averaged local population size estimates (Ashton & Ashton 1981, 1985,
1988) by letting rare = 1, u n c o m m o n = 2, and common = 3. If the average among habitats was less than 2,
for consistency w e called the local population size everywhere small; if the average was greater than 2, we
called the local population size somewhere large. Kolmogorov-Smirnov Tests for Goodness of Fit could not
distinguish significant (dO < 0.05) differences in the distribution of taxa among categories between either the
two plant schemes or the three amphibian and reptile
schemes.
McCo£& Mushins~
PLANTS
50
40
P
E
R 30
0
E 2O
N
T 10
0
m
1
2
8
4
6
8
r
8
7
8
CATEG(~Y
l"-lSOl-lElt I
it'~ISOtEME II
ANIMALS
50
P
E
R
40
80
0
Results
Rarity and Commonness
The distributions of scrub plants and of amphibians and
reptiles among categories of rarity and commonness
(Fig. 1 ) are similar in several ways. For both plants and
amphibians and reptiles, most taxa (50% and 49%, respectively) fall into category 8, the one category of commonness. Also, for both groups, no taxa are geographically narrow, broad in habitat requirements, and small in
local population everywhere (type 3 rarity in Table 1 ),
nor are any geographically widespread, broad in habitat
requirements, and small in local population size everyw h e r e ( t y p e 7 rarity in Table 1). Finally, for both
groups, relatively many taxa (29% and 22%, respectively) are geographically narrow, restricted to few habitats, have either small in local population everywhere
(type 1 rarity in Table 1) or a large in local population
somewhere (type 2 rarity in Table 1).
The distributions of scrub plants and of amphibians
and reptiles among categories of rarity differ in two
principal ways. For plants, relatively many taxa ( 1 6 % )
are geographically narrow, broad in habitat requirements, and large in local population somewhere (type 4
rarity in Table 1). No amphibian or reptile taxon dis-
Conservation Biology
Volume 6, No. 4, December 1992
E
N
T
20
10
0
I
2
4
5
8
CATEGOFIY
I-'-18OHEME I
II~'~8CHEME II
~ S C H E M E III
Figure 1. Percent o f taxa assigned to categories o f
rarity and commonness f o r scrub plants (top) and
scrub amphibians and reptiles (bottom).
plays this type of rarity. For amphibians and reptiles,
relatively many taxa ( 3 0 % ) are geographically widespread, restricted in habitat requirements, and large in
local population somewhere (type 6 rarity in Table 1 ).
Relatively few plant taxa ( 3 % ) display this type of rarity.
Overall, the distribution of taxa among categories is not
the same for the two groups of organisms, as judged by
the Kolmogorov-Smirnov Test (p < 0.05).
Endangered or Potentially E n d ~ e r e d T a n
Thirty-four of the taxa of characteristic plants of the
Sand Pine scrub of peninsular Florida are listed by Wood
McCoy& Mush/risky
Rar/ty of F/or/da Scrub 0rgaMsms
( 1 9 8 8 ) as endangered or potentially endangered, as are
eight of the taxa of characteristic amphibians and reptiles. ( N o t e that for our analysis, w e l u m p e d all listed
taxa together, even though s o m e certainly are m o r e at
risk of extinction than others.) These listed taxa are not
distributed randomly a m o n g the categories of rarity and
c o m m o n n e s s (Fig. 2): regardless of which scheme is
PLANT SCHEME I
2
C
I
A e
T
4
E
G6
I
D
I
0
Re
YZ
80
eO
20
4O
0
20
PEF~ENT
40
80
0O
PERCENT
ANIMAL SCHEME III
iIkk\\\\\kk\kkkk\\!
2
C
A e
T
4
E
Ge
0
kk\\\\\\\\\\\\l
Re
YZ
8,
O0
60
40
80
20
PERCENT
10
I
0
10
20
30
40
60
00
PERCENT
Figure 2. Expected (left) and actual (rigbO percent
of endangered and potentially endangered taxa assigned to categories of rarity and commonness for
scrub plantg Scheme I (top), and scrub amphibians
and reptlle~ Scheme Ill (bottom). Expected percents
are calcuiated from the distribution o f all taxa
among categories
541
employed, too many taxa are to be found in categories
1 or 2, and too few in category 8 (see Table 1). W e
e x p e c t e d this result; otherwise w e w o u l d have judged
the current system for placing organisms on lists of endangered or potentially endangered taxa to be drastically inappropriate. What w e did not expect is that a few
taxa found in category 8 are listed by W o o d (1988), and
that some other taxa are not listed yet display the same
kinds of rarity as taxa that are listed.
Two listed plant taxa fall into category 8 no matter
which of the two categorization schemes is employed,
and o n e listed reptile taxon falls into category 8 if
Scheme I is employed (it falls into category 7 if Scheme
II is employed). The two plant taxa are llex ambigua
(Aquifoliaceae) and Seiaginella arenicola (Selaginellaceae), b o t h of which are considered threatened by the
State of Florida (Preservation of Native Flora of Florida
Act, Section 581.185-187, Florida Statutes). The reptile
taxon is the Indigo Snake, Drymarchon corais couper~
which also is considered threatened by b o t h the State of
Florida (Section 39-27.003-005, Florida Administrative
Code) and the federal g o v e r n m e n t (List of Endangered
and Threatened Wildlife and Plants, 50 CFR 17.11-12).
Another taxon of characteristic scrub plants, Quercus
inopina (Fagaceae), falls into category 1 if Scheme II is
employed, yet is not listed by W o o d (1988). The same
is true of four taxa of characteristic scrub reptiles if
categorization Scheme III is employed: the Peninsula
Mole Skink, Eumeces. egregius onocrepig the Florida
W o r m Lizard, Rhineura ftoridan~ the Coastal Dunes
Crowned Snake, Tantilia reltcta pamlic~ and the Peninsula Crowned Snake, Tantilla r relictct Obviously,
these five taxa would be joined by many others if w e
w e r e to include those taxa in the rest of the categories
of rarity ( 2 - 7 ) that are not listed by W o o d (1988).
To illustrate the discrepancy b e t w e e n the rarity of
taxa and their status as endangered or potentially endangered m o r e clearly, w e focus on the amphibian and
reptile taxa in the appendix. First, w e need to decide,
based on our categorization of rarity, which taxa should
be listed as endangered or potentially endangered. Assuming, as suggested by Rabinowitz et al. ( 1 9 8 6 ) and
Thomas and Mallorie (1985), that the m o s t vulnerable
species are likely to be those that are b o t h geographically narrow and restricted to few habitats, w e conclude
that all taxa in categories 1 and 2 (see Table 1) should
be listed. Further, for the sake of consistency, w e conclude that the taxa within any other category either
should all be listed or should all be unlisted. Under
Scheme III (see Table 2), only three (State of Florida) or
four (federal g o v e r n m e n t ) of the eight amphibian and
reptile taxa in categories 1 and 2 are listed; and four
(State of Florida and federal g o v e r n m e n t ) of the amphibian and reptile taxa in categories 5, 6, and 7 are listed,
but eleven are not. We suggest that the discrepancy
b e t w e e n the rarity of taxa as w e have categorized it and
Conservation Biology
Volume 6, No. 4, December 1992
542
R ~ oI Horida Scrub Orsanisms
McCoy& Musfiinsky
Table 2. Percentages of taxa of four groups of organisms that
are geographically mrrow, have restricted habitat specllicities, or
have small local population sizes.
Percentages
Scrub plants
Scheme 1
Scheme 2
Scrub amphibians
and reptiles
Scheme 1
Scheme 2
Scheme 3
Narrow
ranges
Restricted
habitats
Small
populations
46
46
34
34
16
36
22
22
22
51
51
51
3
30
43
the listing of taxa as endangered or potentially endangered is substantial for this group of organisms.
Another Conception of garity for Scrub Plants
Some people familiar with "rare" plants in the Sand Pine
scrub habitat had reservations about our categorization
schemes. They thought that labeling as "narrow" any
taxon w h o s e total range is encompassed by the State of
Florida was too liberal. In large part, their reaction
seemed to stem from fear of a "dilution effect"; that is,
because our criterion allowed nearly 50% of the taxa to
be thought of as geographically narrow, it could lessen
the attention given the twenty or so taxa found only on
the central Florida ridges (see Christman & J u d d 1990).
Some people also did not like our criterion for separating broad from restricted habitat specificity. Invariably,
our criterion segregated taxa occupying only scrub and
taxa occupying scrub and ostensibly similar sandhill
(see Myers 1990) from the other taxa. Our critics tend
to discriminate finely a m o n g types of scrubs (such as
"oak scrub," "rosemary scrub," "white-sand scrub," "yellow-sand scrub), and as a result are likely to conceive of
"restricted habitat specificity" as applicable to taxa that
occupy but one or a few of these types of scrub. Certainly they are not likely to conceive of the term as
applicable to taxa that o c c u p y b o t h a variety of types of
scrub and also sandhill. Finally, some people reminded
us that published designations of taxa as " c o m m o n , "
" u n c o m m o n , " and "rare" are not likely to have resulted
solely from consideration of population size, but from
simultaneous consideration of geographic range, habitat
specificity, and population size. They maintained, in fact,
that because the sources of our information w e r e principally taxonomic rather than ecological treatises, it is
likely that geographic range played a larger role than
either habitat specificity or population size in arriving at
the designations.
To address these concerns, w e asked two botanists
from Archbold Biological Station, Eric Menges and Nor-
ConservationBiology
Volume6, No. 4, December1992
een Gallo, both of w h o m study the plants of the Sand
Pine scrub habitat, to place the 122 taxa listed in the
appendix into the same categories as w e had used. We
asked t h e m to retain our criterion for geographic range
( n o t restricted to Florida versus restricted to Florida).
We rejected the suggestion that a better criterion w o u l d
separate out the few taxa found only on the central
Florida ridges, because these taxa also are found solely
or largely in scrub habitat and thus automatically are
restricted in their habitat specificity (the p r o b l e m of
"double counting"). We gave Menges and Gallo no guidance for setting criteria for habitat specificity or population size.
Menges and Gallo felt confident in assigning 109 of
the 122 taxa to categories of rarity and commonness.
Under their scheme, 47% of the taxa have n a r r o w
ranges, 20% restricted habitat specificities, and 21%
population sizes that are everywhere small. C o m p a r e d
to our categorization schemes (see Table 2), theirs displays a m u c h reduced tendency to label the habitat
specificity of a taxon "restricted." This difference results
mostly from the fine discrimination a m o n g types of
scrub habitat that w e mentioned previously. The relative n u m b e r of taxa that they thought had population
sizes that are e v e r y w h e r e small c o m p a r e d favorably
w i t h the n u m b e r d e r i v e d f r o m o u r c a t e g o r i z a t i o n
Scheme 1 (see Table 2), in which only taxa labeled
"rare" by our sources of information w e r e considered to
have population sizes that are e v e r y w h e r e small.
The overlap b e t w e e n the categorization scheme developed by Menges and Gallo and our schemes is substantial. Their scheme placed 79% of 109 taxa into the
same categories as our Scheme I, and 73% into the same
categories as our Scheme II. These p e r c e n t a g e s are
somewhat misleading, however, because m u c h of the
overlap came either from taxa that Menges and Gallo's
scheme placed into the single category of c o m m o n n e s s
(98% overlap with our Scheme I and 89% with our
Scheme II), or from taxa that their scheme identified as
geographically narrow, restricted to few habitats, and
having population sizes that are e v e r y w h e r e small ( t y p e
1 rarity in Table 1) (100% overlap with either of o u r
schemes). Their scheme placed the threatened llex ambigua and Selaginella arenicola into the single category of commonness, as had b o t h of our schemes (see
above). For the other six categories (types 2 - 7 rarity in
Table 1), Menges and Galio's s c h e m e coincided less
well with ours, again mainly because of the difference
b e t w e e n criteria used to separate taxa with broad habitat specificities from those with narrow ones. Menges
and Gallo's placement of Quercus inoptna a m o n g categories of rarity and c o m m o n n e s s ( t y p e 4 rarity in Table
1) makes its absence from the listing of endangered or
potentially endangered taxa less of a mystery than it
appeared from our schemes ( t y p e 1 rarity in Table 1).
McCoy& Mushinslty
Another Conception of Rarity for Scrub Amphibians
and Reptiles
Burke and H u m p h r e y ( 1 9 8 7 ) c o m p a r e d the apparent
"vulnerability" of selected taxa, including amphibians
and reptiles, in Florida with the designations of those
taxa as endangered or potentially endangered by gove r n m e n t agencies. They assessed vulnerability by determining "initial rarity," because they assumed that a
taxon that is rare to begin with is in greater danger of
extinction than one that is not. They considered (p. 97)
" . . . an animal [that] is either very limited in distribution,
or widespread but quite u n c o m m o n locally" to be "initially rare." Rarity, according to this definition, is equivalent to two of the aspects of rarity that we, following
Rabinowitz et al. (1986), have employed: geographic
narrowness and local population size everywhere small.
To categorize the vulnerability of amphibians and reptiles in Florida, Burke and H u m p h r e y ( 1 9 8 7 ) used three
primary indications of rarity: limited distribution, low
local relative density, and large body size. They awarded
a taxon one point for each of these characteristics it
possesses, or two points if they judged the condition to
be extreme. For example, limitedxlistribution was taken
to be 50% or m o r e of a taxon's entire range within
Florida, and the range within Florida comprising 1 0 25% of the State; a taxon meeting these criteria was
awarded one point. A taxon was awarded two points if
its range within Florida comprises less than 10% of the
State. Burke and H u m p h r e y ( 1 9 8 7 ) determined relative
densities of taxa from their o w n field experiences as
well as those of others. They n o t e d taxa with low or
e x t r e m e l y low relative densities and awarded t h e m one
or two points each, respectively. They also noted taxa
that are relatively large c o m p a r e d to similar taxa (such
as the largest 20% of snake taxa), and awarded t h e m one
point each. The largest taxon within various groupings
of taxa (snakes, turtles, e t c . ) w a s awarded two points, as
w e r e other exceptionally large taxa ( s u c h as marine turties). Burke and H u m p h r e y ( 1 9 8 7 ) designated taxa with
four or m o r e points " e x t r e m e l y vulnerable," those with
three points "very vulnerable," and those w i t h two
points (plus other, subjective "sensitive factors") "moderately vulnerable." Taxa not falling under any of these
three designations but listed as endangered or potentially endangered by s o m e g o v e r n m e n t agency w e r e
termed "possibly vulnerable."
We examined the match b e t w e e n the rarity of taxa as
Burke and H u m p h r e y ( 1 9 8 7 ) categorized it and the listing of taxa as endangered or potentially endangered, in
the same way that w e did for our o w n categorization.
We focused again on amphibians and reptiles, but found
it m o r e difficult to decide, a pr/or~ w h i c h taxa should
be listed as endangered or potentially endangered. We
settled on the following. All taxa in the categories that
Rarityo[ Florid~Scrub Organisms
543
Burke and H u m p h r e y ( 1 9 8 7 ) called " e x t r e m e l y vulnerable" and "very vulnerable" should be listed, and the
taxa in the category they called "moderately vulnerable" either should all b e listed or should all be unlisted.
Only four (State of Florida ) or five ( federal g o v e r n m e n t )
of the seven amphibian and reptile taxa in the first t w o
categories are listed by W o o d (1988); one of the amphibian and reptile taxa in the third category is listed,
but two are not. We conclude that the discrepancy between the rarity of taxa as Burke and H u m p h r e y ( 1 9 8 7 )
categorized it and the listing of taxa as endangered or
potentially endangered is about as great as it is using our
categorization schemes.
Discussion
We have reviewed some conceptions of rarity and commonness as they apply to the Sand Pine scrub habitat of
Florida. While w e very m u c h agree with others w h o
have struggled with the meaning of rarity ( s u c h as Hubbell & Foster 1986; Rabinowitz et al. 1986; Burke &
H u m p h r e y 1987), that objective categorization of rarity
and c o m m o n n e s s is an important undertaking, w e are
impressed with the difficulty in accomplishing it. One
reason for the difficulty that w e have not addressed specifically to this point is that the characteristic taxa of the
Sand Pine scrub habitat, particularly the plants, are not
as well known as, say, the plants of the British Isles. ( W e
hasten to note, however, that the scrub is better k n o w n
than many other habitats in Florida.) N e w taxa still are
b e i n g d i s c o v e r e d ( s u c h as Crotolaria avonensis,
Delaney & Wunderlin 1989; Dicerandra cht~tmanii,
Huck et al. 1989) or rediscovered ( s u c h as Ziztphus
celatg Delaney et al. 1989). The effect of the addition of
"new" taxa such as these to the list of scrub inhabitants
obviously is to change the distribution of taxa a m o n g
categories of rarity and commonness, but it is a change
of a particular kind. These taxa are rare no matter h o w
rarity is judged (type 1 rarity of Table 1 ), and it is almost
certain that any taxa that are still "missing" are the same.
Other reasons for the difficulty in categorizing the
rarity and c o m m o n n e s s of scrub taxa include distinguishing geographically wide from geographically narr o w taxa, taxa with b r o a d habitat specificities f r o m
those with restricted habitat specificities, and taxa with
population sizes that are s o m e w h e r e large from those
with population sizes that are e v e r y w h e r e small. The
first distinction w o u l d seem relatively easy to make, because it requires only knowledge of the distribution of
the taxa in space. Yet one must settle on a hard-and-fast
criterion in advance for distinguishing b e t w e e n these
two kinds of distribution. The p r o p e r criterion to b e
employed, if indeed a single criterion exists, certainly is
not obvious. The other two distinctions require assump-
Conservation Biology
Volume 6, No. 4, December 1992
544
P.,crityof Rot'ida Scrub O ~ s m s
tions to b e granted concerning the identification of habitats and the estimation of populations size. Whether or
not these assumptions are well met is problematic. For
example, w e took our estimates of population size from
published sources, and these sources may well have
confused geographic range, habitat specificity, and population size in their classifications. When our criterion
for distinguishing population sizes that are somewhere
large from those that are everywhere small was augmented with field experience of experts, however, the
relative number of taxa of each sort was not dramatically changed. We note that both Burke and Humphrey
( 1 9 8 7 ) and Rabinowitz et al. ( 1 9 8 6 ) see field experience as a valuable means of judging population size.
Two additional, practical, problems exist in determining population size, at least for plants. The first is that
several taxa of scrub plants are clonal, and therefore the
classic question arises of what constitutes an individual
in such taxa~ Furthermore, even if this question were to
be answered satisfactorily, it w o u l d remain unclear
whether rarity is expressed similarly in clonal and nonclonal plants. If not, then these two kinds of plants may
need to be treated independently in developing conservation strategies. The second problem is that seed banks
in the soil underlying a scrub may contain viable seeds
of taxa that are not represented aboveground. As these
seeds could germinate under proper conditions, are
such taxa really present in the scrub? If such taxa are
counted as present, should their population sizes be
equal to the number of seeds? For that matter, should
the viable seeds of all species in the seed bank be added
to calculations of population size? These two problems,
and others encountered w h e n attempts are made to discriminate between types of habitat specificity and local
population size, reinforce our earlier contention that
the criteria that should be employed to place scrub taxa
into categories of rarity and commonness are not obvious.
Even if the difficulties in categorizing the rarity and
commonness of scrub taxa were to be addressed successfully, some important philosophical considerations
remain. The first is the objective of conservation, since
no single objective is always considered to be most important. Should the focus be on preserving rare scrub
taxa at all, on preserving diversity, or on something else
entirely? If the focus is to be on multiple objectives, are
the means of achieving those objectives compatible?
Shrader-Frechette and McCoy (in press) discuss questions such as these in detail. If the focus is to be on rare
scrub taxa, then criteria for identifying such taxa must
be agreed upon in advance, which is a difficult undertaking, as w e have shown.
Rarity certainly is not expressed in the same way by
all organisms. For example, the distribution of British
plants among the eight categories of rarity and commonness (from Rabinowitz et al. 1986) is not the same as the
Conservation Biology
Volume 6, No. 4, December 1992
McCoy & Mushlnsky
distribution of butterflies of the Atlas Mountains of Morocco among the same categories (Thomas & Mallorie
1985) (Kolmogorov-Smirnov Test, p < 0.05 in both
cases). Neither of these distributions, in turn, is the
same as those for scrub plants or scrub amphibians and
reptiles (Kolmogorov-Smirnov Test, p < 0.05 in all
cases). When we ranked the relative representation of
each category for the four distributions, from 1 equal to
the largest percent of taxa to 8 equal to the smallest
percent of taxa, we found that the rank-order of categories is different among all four (Spearman Rank Order
Correlation, p > 0.05 in all cases). Our results indicate
that rarity is not expressed in the same way by scrub
plants as by scrub amphibians and reptiles. Rarity even
may be expressed differently within these taxonomic
groupings, as we suggested for clonal versus nonclonal
plants. These conclusions suggest that some fundamental difference exists in the way rarity is expressed by
different organisms in different ecological settings or in
the way it has been measured by different investigators,
or both.
We concluded that the match between the designation of some scrub taxa as endangered or potentially
endangered (see W o o d 1988) and our judgment of their
rarity was not good. In particular, w e thought that several presently unlisted taxa of amphibians and reptiles
warranted listing (see Burke & Humphrey 1987), based
on our categorization of their rarity. The absence of
these taxa from the list of endangered or potentially
endangered taxa could be for one or a combination of
several reasons. One potential reason for their absence
is that we made errors in our categorization schemes,
and the taxa in question are not as rare as they seem (in
other words, they do not truly display either type 1 or
type 2 rarity). Another potential reason for their absence is that the taxa in question have been overlooked
in the listing process, and actually should be listed. Yet
another potential reason is that the listing process is
complex and incorporates considerations b e y o n d those
we have used to place taxa in categories of rarity and
commonness.
Precisely what additional considerations might influence the decision of whether or not to include a particular taxon on a list of endangered or potentially endangered taxa? We can tabulate seven considerations,
although we are sure that many more could be found
(note that not all of these considerations apply equally
well to all taxa). The first three considerations have to
do with the ecological roles that organisms play and the
other four have to do with human judgments about organisms. The seven considerations are ( 1 ) body size, because larger organisms are more likely to be at risk of
extinction than smaller but otherwise similar organisms
(see Burke & H u m p h r e y 1987; Harris & Gallagher
1989); ( 2 ) trophic position, because in general carnivores are more likely to be at risk of extinction than
McCoy& Mush~/ty
herbivores (see Burke & Humphrey 1987; Harris & Gallagher 1989); ( 3 ) ecological relationships, because
"keystone species" are more likely to affect the risk of
extinction of other taxa than are nonkeystone species
(see Soule & Simberloff 1986; Burke & H u m p h r e y
1987); ( 4 ) substantial population reduction in the past
without substantial recovery, or severe risk of extinction presently or in the future, because taxa so judged
by definition are more at risk of extinction than taxa not
so judged; ( 5 ) public opinion, because popular taxa are
likely to receive more attention from government officials than unpopular or unfamiliar ones (see Duda
1987); ( 6 ) value as human possessions, because taxa
that have such value are more at risk of extinction than
similar taxa that do not (note, for example, that many
taxa are listed by W o o d [1989] solely because of their
designation by the Convention on International Trade in
Endangered Species of Wild Floras and Fauna [CITES] as
taxa whose risks of extinction have been increased by
their commercial importance); and ( 7 ) political boundaries, because a taxon that has a limited distribution in
one geopolitical unit (a state, for example) may be considered rare in that unit, regardless of its status elsew h e r e (note, for example, the listing o f T a m i a s striatus,
the Eastern Chipmunk, in W o o d [ 1988]). Recognition of
the complexity of the listing process supports the conclusion of Burke and Humphrey ( 1 9 8 7 ) and those w h o
have studied ways of assessing "conservation value"
(such as Margules & Usher 1981; Margules 1986; Usher
1986) that multiple screening techniques should be employed to judge which taxa are in need of human assistance.
Our particular conclusions about conservation of the
Sand Pine scrub habitat reinforce the general conclusions of Rabinowitz et al. ( 1 9 8 6 ) and May ( 1 9 8 8 ) about
the value of placing organisms into categories of rarity
and commonness. Whether rarity is the sole criterion
for a conservation strategy or only one of several criteria, a clear understanding of h o w a particular taxon is
"rare" is essential to make the strategy sound. We believe the major value of placing organisms into categories of rarity and c o m m o n n e s s to be as insurance against
overlooking taxa in need of human assistance. As w e
have argued, the current set of reasons for placing a
taxon on an official list of endangered and potentially
endangered taxa is large and complex. Government
agencies responsible for compiling these lists must be
convinced that a particular taxon deserves inclusion.
Certain taxa, such as those that are small and unspectacular or those that have cryptic habits, could be overlooked amidst all the complexity simply because no
case is made for their inclusion due to lack of information about their habits. For example, the four taxa of
reptiles that our analysis indicated to be critically rare,
but that are not listed, are small fossorial forms about
w h o m little is known. Should these four taxa be listed?
Rar/ly of F/ot~da Scrub Organ/sins
545
We cannot say yes with assurance, b u t w e can say, based
on our analysis, that they should at least be considered
for listing,
Acknowledgments
We thank Eric Menges and Noreen Gallo for the many
hours that they spent helping us place scrub plants into
categories of rarity and commonness. Eric and Noreen,
as well as Mark Deyrup~ Steve Humphrey, and Kristin
Shrader-Frechette, read various versions of this paper
and provided us with valuable suggestions for its improvement.
,~
Literature Cited
Ashton, 1LE., Jr., and P. S. Ashton. 1981~ Handbook of reptiles
and amphibians of Florida. Part I. The snakes. Windward, Miami, Florida.
Ashton, R. E., Jr., and P. S. Ashton. 1985. Handbook of reptiles
and amphibians of Florid& Part II. Lizards, turtles and crocodilians. Windward, Miami, Florida.
Ashton, IL E., Jr., and P. S. Ashton. 1988. Handbook of reptiles
and amphibians of Florida. Part III. The amphibians. Windward, Miami, Florida.
Breen, IL S. 1963. Mosses of Florida: an illustrated manual.
University of Florida Presses, Gainesville, Florida.
Bucldey, A., and T. O. Hendrickson. 1988. The distribution of
Cladonia perforata Evans on the southern Lake Wales Ridge
in Highlands County, Florida. Bryologist 91:354-356.
Burke, 1LL, and S. 1LHumphrey. 1987. Rarity as a criterion for
endangerment in Florida's fauna. Oryx 21:97-102.
Christman, S. P. 1988. Endemism in Florida's interior Sand Pine
scrub. Florida Nongame Wildlife Program Technical Report. In
press.
Christman, S.P., and W. S. Judd. 1990. Notes on plants endemic to Florida scrub. Florida Scientist 53:52-73.
Conant, IL 1975. A field guide to reptiles and amphibians of
eastern and central North Americ~L Houghton Mifflin, Boston.
Davis, J. H., Jr. 1943. The natural features of southern Florida:
especially the vegetation and the Everglades. Florida Geological Survey Bulletin 25:1-311.
Davis, J.H. 1967. General map of the natural vegetation of
Florida. University of Florida Agricultural Experiment Station
Circular S.178.
Delaney, K. IL, and 1LP. Wunderlin. 1989. A new species of
Crotolaria (Fabaceae) from the Florida central ridge. Sida
13:315-324.
Delaney, IC 17,, IL P. Wunderlin, and B. F. Hansen. 1989. Rediscovery of Ziztphus celata (Rhamnaceae). Sida 13:325-330.
ConservationBiology
Volume6, No. 4, December1992
546
McCoy & M u s ~
Rari0, of Flond~ &x~b Organisms
Deyrup, M. 1989. Arthropods endemic to Florida scrub. Florida Scientist 52:254-270.
Peroni, P. A., and W. G. Abrabamson. 1985~ Vegetation loss on
the southern Lake Wales Ridge. Palmetto 5(3 ):6-7.
Duda, M.D. 1987. Floridians and wildlife: sociological implications for wildlife conservation in Florida. Florida Nongame
Wildlife Program Technical Report 2.
Peroni, P.A., and W. G. Abrahamson. 1985b. A rapid method
for determining losses of native vegetation. Natural Areas Journal 5:20-24.
Fernald, M.L. 1950. Gray's manual of botany, 8th edition.
American Book Company, New York
Rabinowitz, D. 1981. Seven forms of rarity. Pages 205-217 in
H. Synge, editor. The biological aspects of rare plant conservation. J. Wiley, Chichester, U.K.
Fink, B. 1935. The lichen flora of the U.S. University of Michigan Press, Ann Arbor, Michigan.
Rabinowitz, D., S. Cairns, and T. Dillon. 1986. Seven forms of
rarity and their frequency in the flora of the British Isles. Pages
182-204 in M. E. Soule, editor. Conservation biology: the science of scarcity and diversity. Sinauer Associates, Sunderland,
Massachusetts.
Harris, L D., and P. B. Gallagher. 1989. New initiatives for wildlife conservation: the need for movement corridors. Pages 1134 in G. MacKintosh, editor. Preserving communities and cor~TidOrS. Defenders of Wildlife, Washington, D.C.
Richardson, D. 1L 1989. The Sand Pine scrub community: an
annotated bibliography. Florida Scientist 52:65-93.
Hubbell, S. P., and 1L B. Foster. 1986. Commonness and rarity
in a neotropical forest: implications for tropical tree conservation. Pages 205-231 in M. E. Soule, editor. Conservation biology: the science of scarcity and diversity. Sinauer Associates,
Sunderland, Massachusetts.
Shrader-Frechette, IL, and E.D. McCoy. Method in Ecology:
Strategies for Conservation Problems. Cambridge University
Press. (In press.)
Small, J. K. 1933. Manual of the southeastern flora. Published
by author, New York.
Huck, R.B., W.S. Judd, W.M. Whitten, J.D. Skean, Jr., IL P.
Wunderlin, and K. 1L Delaney. 1989. A new Dicerandra (Labiatae) from the Lake Wales Ridge of Florida, with a cladistic
analysis and discussion of endemism. Systematic Botany
14:197-213.
Soul6, M.E., and D. Simberloff. 1986. What do genetics and
ecology tell us about the design of nature reserves? Biological
Conservation 35:19-40.
Long, R.W., and O. Lakela. 1971. A flora of tropical Florida.
University of Miami Press, Coral Gables, Florida.
Thomas, C. D., and H. C. Mallorie. 1985. Rarity, species richness and conservation: butterflies of the Atlas Mountains of
Morocco. Biological Conservation 33:95-117.
Margules, C.R. 1986. Conservation evaluation in practice.
Pages 297-314 in M.B. Usher, editor. Wildlife conservation
evaluation. Chapman and Hall, London.
Thompson, J.W. 1967. The lichen genus Cladonia in North
America. University of Toronto Press, Toronto, Canada.
Margules, C. IL, and M. B. Usher. 1981. Criteria used in assessing wildlife conservation potential: a review. Biological Conservation 21:79-109.
Usher, M. B. 1986. Wildlife conservation evaluation: attributes,
criteria and values. Pages 3-44 in M. B. Usher, editor. Wildlife
conservation evaluation. Chapman and Hall, London.
May, IL M. 1988. How many species are there on earth? science 241:1441-1449.
Wood, D.A. 1988. Orificial lists of endangered and potentially
endangered fauna and flora in Florida. Florida Game and Fresh
Water Fish Commission, Tallahassee, Florida.
Myers, R. L. 1990. scrub and high pine. Pages 150-193 in ILL.
Myers and J.J. EweL editors. Ecosystems of Florida. University
of Central Florida Press, Orlando, Florida.
Wunderlin, R.P. 1982. Guide to the vascular plants of central
Florida. University Presses of Florida, Gainesville, Florida
Appendix
Characteristic plants, amphibians, and reptiles in the Sand Pine scrub habitat of peninsular Florida (after Christman 1988). For each
taxon, w e indicate ( ° ) listing as endangered or potentially endangered by Wood (1988), and present our categorizations---by two
(plants) or three (amphibians and reptiles) schemes---of rarity or commonness (from Table 1 ).
Plants
Andropogon bracbystacbyus
Andropogon tracyi
Artsttda gyrans
Asclepias tuberosa
Asi m ina tetramera
Befaria racemosa
Bulbostylis ctltatifolta
Bumelia lacuum
Calamtntha ashei
Ceratiola erlcoides
Chionanthus 1 7 y g ~
Cladina evansii
Cladonia calycantha
Cladonia prostrata
Conservation Biology
Volume 6, No. 4, December 1992
*
*
*
4
5
8
8
1
8
8
4
4
2
1
8
8
8
4
5
7
8
1
8
8
4
3
2
1
8
8
7
Andropogon floridanus
Andropogon virgintcus glaucus
Ascleptas curtissii
Asimina obovata
Balduina angustifolia
Bo n a m t a grandiflora
Bulbostylt$ warei
Bumelta tenax
Carya floridana
Chapmannta floridana
Chrysopsts floridana
Cladina subtenuis
Cladonia leporina
Clitoria fragrans
*
*
*
*
4
8
1
4
8
1
8
8
2
4
1
8
8
1
4
8
1
4
8
1
7
8
2
4
1
8
8
1
McCoy & Mus/zMs/~
Rari~ of F/orida Scrub OrgaMsms
547
8
4
8
1
1
8
8
3
8
1
1
8
2
4
8
8
8
1
3
8
8
8
2
8
2
8
Appendix continued.
8
1
1
8
1
1
8
Cnidoscolus stimulosus
Conradina brevifolia
Crataegus c f. lepida
Dalea f e a y i
Dicerandra cornutissima
Dicerandra i m m a c u l a t a
Diodia teres
Eryngium cunifolium
Euphorbia polyphylla
Garberia heterophylla
Gratioia htsptda
Helianthemum
corymbosum
Hypericum cumulicola
Ilex ambigua
Lechea cernua
Liatris laevigata
Ltcania m i c h a u x i i
Lupinus aridorum
Lyonia ferruginea
Lyonia lucida
Nolina brittoniana
Osmanthus megacarpus
Pantcum breve
Paronychia chartacea
Persea humilis
Pinus clausa
Pttyopsis gramtnifolia
Polygala lewtonii
Polygonelia ciliata
Polygonella myriophylla
Polygonella robusta
Prunus geniculata
Quercus geminata
Quercus myrtifolia
Sabal etonia
Schrankia microphylla
Serenoa repens
Sisyrinchium xerophyllum
Solidago chapmanii
Stipa avenacioides
Stylisma abdita
Tephrosia chrysophylia
Tillandsia usneoides
Trichostema d i c h o t o m u m
Vaccinium darrowii
Vitis m u n s o n i a n a
X t m e n i a americana
1
4
2
4
8
1
8
2
8
8
1
8
8
4
2
4
2
2
8
8
1
4
2
4
1
8
8
2
8
8
2
8
4
3
8
8
8
8
8
4
1
4
2
4
Commelina erecta
Conradtna grandtfolia
Cyperus retrorsus
Dicerandra cbr~rmanii
Dicerandra frutescens
Dtcranum condensatum
Eriogonum longifolium
gnaphalifolium
Euphorbia cf. floridana
Gaiactia elliotii
Gaylussacia dumosa
Hedyotis procumbens
8
1
8
2
8
8
1
8
8
3
2
3
1
2
8
8
1
3
1
4
1
8
8
1
8
8
2
8
4
3
8
8
8
8
8
4
Helianthemum nashii
Hypericum reductum
llex cumulicoia
Lechea deckertii
Liatris ohlingerae
L inaria floridana
Lygodesmia aphylla
Lyonia fruticosa
Monotropa uniflora
Opuntia humifusa
Palafoxia f e a y i
Paronychia americana
Paronychia herniarioides
Piloblephis rigida
Pinus elliottii
Poianisia tenuifolia
Polygonelia basiramia
Polygonelia gracilis
Polygonelia p o l y g a m a
Polypremum procumbens
Quercus chapmanit
Quercus inopina
Rhynchospora megalocarpa
Schizachyrium niveum
Seiaginelia arenicoia
Seymeria pectinata
Smilax auriculata
Stilltngia sylvatica
Stipulicida setacea
Styltsma patens
Tillandsia recurvata
Tradescantia roseolens
Usnea strigosa
Vaccinium myrsinites
Warea carteri
Ziziphus celata
*
*
*
*
*
*
2
1
6
5
1
1
4
8
8
8
8
4
8
6
4
8
8
4
8
8
7
8
4
7
5
4
8
8
1
1
8
8
8
8
2
6
8
8
8
8
1
6
*
2
1
*
8
8
8
8
8
8
4
8
8
8
8
8
8
8
8
4
8
7
8
8
*
*
2
1
1
1
Amphibians
Bufo quercicus
Eleutherodactglus p.
pianirostris
Hyia femoralis
Rana areoiata aseopus
6
Bufo terrestris
8
8
8
8
8
5
Gastrophryne carolinensis
Notophthalmus perstrtatus
Scaphtopus h. holbrooki
8
6
6
8
5
6
8
5
5
Anolis caroltnensis
Cnemidophorus
sexlineatus
Crotalus adamanteus
Drymarchon corals couperi
Eumeces egregius lividus
Eumeces inexpectatus
8
Cemophora c coccinea
6
6
5
6
7
7
1
8
Coluber constrictor priapus
Diadophis p. punctatus
Elaphe ~ guttata
Eumeces eMegius onocrepis
Gopherus polyphemus
8
8
8
2
6
8
8
8
1
6
8
8
8
1
6
Reptiles
Conservation Biology
Volume 6, No. 4, December 1992
548
RarRFof Florida Scrub Organisms
McCoy & M a s ~
Appendix continued.
Heterodon platyrhinos
Lampropeltt$ t r i a n g u l u m
elapsoides
Micruru$ f. f u l v t g s
Opheodrys aestivus
6
6
6
Heterodon $imus
6
6
6
8
8
8
7
8
8
7
7
8
8
2
8
1
8
1
8
8
8
Ophisaurus ventralis
8
8
8
Rhineura florldana
Sceloporus woodi
Sttlosoma extenuatum
Tantilla r. relicta
2
2
1
2
1
2
1
2
1
2
1
1
Masticophis fl flagellum
Neoseps reynoldsi
Ophtsaurus attenuatus
longicauda
Pituophis melanoleucu~
mugttus
Sceloporus tL undulatus
Sistrurus miliarius barbourl
Tanttlla relicta pamlica
6
6
8
2
5
6
8
1
5
6
8
1
ConservationBiology
Volume 6, No. 4, December 1992
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