O R I G I N A L
A R T I C L E
Life-history characters and phylogeny are
correlated with extinction risk in the
Australian angiosperms
A. Sjo¨stro¨m
1
and C. L. Gross
2
*
1
School of Mathematics, Statistics and
Computing Science and
2
Ecosystem
Management, School of Environmental
Sciences and Natural Resources Management,
University of New England, Armidale, NSW,
Australia
*Correspondence: C.L. Gross, Ecosystem
Management, School of Environmental Sciences
and Natural Resources Management, University
of New England, Armidale, NSW, 2351,
Australia.
E-mail: cgross@une.edu.au
These authors contributed equally to this work.
A B S T R A C T
Aim To determine whether life-history characters that affect population
persistence (e.g. habit and life span) and those that influence reproductive
success (e.g. sexual system and fruit type) are non-randomly correlated with
extinction risk (i.e. threat category) in the Australian flora (c. 19,000 species, of
which c. 14% is threatened). To identify patterns that present useful conservation
directions. To understand patterns of extinction risk in the Australian flora at a
broad scale.
Location Continental Australia.
Methods A country-wide exploration of four life-history characters in the
Australian flora (n
¼ 18,822 species) was undertaken using reference texts, expert
opinion, herbarium records and field work. For each character and threat-
category combination, a G-test (using a log-linear model) was performed to test
the null hypothesis that the two factors were independent in their effects on
count. A generalized linear model (GLM) with a logit link and binomial error
distribution was constructed with the proportion of taxa in each extinction risk
category as the response variable and the habit, sex and fruit-type characters as
explanatory terms. In a separate approach, we investigated patterns across the
threat categories of non-endangered extant, endangered, and extinct using a
multinomial model. We examined whether or not species-poor genera were more
likely to contain threatened or extinct species than species-rich genera. A GLM
with a binomial error distribution and logit link function was constructed to
obtain a weighted regression on the proportion of species listed as extinct or
endangered within a genus versus the log of the size of the genus. We also used a
supertree analysis and character tracing to investigate the role of phylogeny on
extinction risk.
Results We found that the Australian flora is primarily composed of bisexual
shrubs with dry-dehiscent fruits. Dioecious breeding systems (separate female and
male flowers on separate plants) in many floras are the predominant unisexual
system, but in Australia there are unexpectedly high levels of monoecy (separate
female and male flowers on the same plant). Within the extinct data set of
31 species we detected a significant departure from that expected for habit but not
for life span, sexual system or fruit type. There are significantly fewer trees on the
extinct list than expected. This may reflect the greater resilience of trees than of
other growth habits to extinction processes as well as the observation time-frame.
Within the endangered data set of 450 species we found significant differences in
the representation of the observed characters from that expected within sex
systems and fruit types. We show that, depending on the life form, unisexual
breeding systems can be significantly and positively associated with endangered
species compared with non-threatened species. For example, there are more
Journal of Biogeography (J. Biogeogr.) (2006) 33, 271–290
ª 2006 The Authors
www.blackwellpublishing.com/jbi
271
Journal compilation
ª 2006 Blackwell Publishing Ltd
doi:10.1111/j.1365-2699.2005.01393.x
I N T R O D U C T I O N
There are many different types of events that can increase
extinction risks in species; for example, fragmentation has
multiple effects on ecosystems (Laurance et al., 2002) and is a
key factor worldwide that can prematurely halt population
persistence. However, it is not always that a species was just in
the wrong place at the wrong time – even related species in the
same landscape can differ in their resilience to perturbations
(e.g. Bertya ingramii versus B. rosmarinifolia, Scott & Gross,
2004). Are there inherent properties in species that predispose
them to vulnerability or resilience? A broad approach to
address this question is to determine whether or not there are
specific traits clustered with the state of extinction risk.
Increasingly this approach is being used to evaluate the
properties of rarity and speciosity geographically or within
lineages (e.g. Hegde & Ellstrand, 1999; Rey Benayas et al.,
1999; Edwards & Westoby, 2000; Murray et al., 2002a,b;
Golding & Hurter, 2003) in an attempt to forecast the types of
species that may be vulnerable to extinction. The evolutionary
significance of trait clustering can also be examined using
correlation tests of life-history characters against ecological
parameters (e.g. Chazdon et al., 2003). However, seldom is
there a comprehensive data set that covers whole continents
(see later). Consequently an overall appraisal of extinction risk
is mostly lacking at continental scales. In most floras, for
example, so little is known about the distribution of life-
history characters on a continental scale that partial data sets
(e.g. a clade, Murray et al., 2002a) are used instead, with the
added power of phylogenetic analyses in some cases (e.g.
Murray et al., 2002b; Murray & Lepschi, 2004). Biogeographi-
cal attributes such as habitat type may also be important
predictors of increased extinction risk; however, our initial
focus is at the Australia-wide scale and on whether or not there
are life-history attributes correlated with increased extinction
risks.
Perhaps the predominance of a life-history character (e.g.
habit) is skewed in abundance in both threatened species and
the greater population – it is difficult to resolve when data on
the greater population are unavailable. The Australian vascular
flora presents a challenge in this area: there are at least 19,000
vascular species yet the abundance and distribution of
fundamental life-history characters, such as those that affect
population persistence (e.g. habit and life span) and those that
influence reproductive success (e.g. sexual system and fruit
type), are poorly known on a continental basis. Such data, if
available, could be used to examine the general occurrence of
patterns of rarity in the flora. There is certainly a need for a
broad approach as the estimate for the number of threatened
vascular plants in Australia is alarmingly high at 14.4% (Walter
& Gillett, 1998).
Establishing the abundance and distribution of life-history
characters for an entire flora is a challenge, yet knowledge of
these properties at such a broad and inclusive scale could be a
powerful tool for conservation planning. As a starting point we
undertook a study of the distribution of four life-history
characters that we consider fundamental to all species. These
characters were habit, life span, sex system and fruit type, and
they were examined for Australian recently extinct and
endangered angiosperms and for the Australian flora as a
whole. Habit (i.e. life form) has been linked to increased
extinction risk in several floras (Robinson et al., 1994; Turner
et al., 1996; Hegde & Ellstrand, 1999; Rogers & Walker, 2002)
and it is intricately linked with life span (Garcia, 2003). Sex
system can also be associated with elevated extinction risks,
particularly for unisexual species. For example, Vamosi &
Vamosi (2005) found that dioecious species experience higher
extinction rates and (or) lower speciation rates compared with
non-dioecious sister groups. They also found that the woody
growth habit is probably a contributing factor to the higher
incidence of dioecious species being at risk of extinction but
that the character was not solely responsible for the pattern.
Certain fruit types can be non-randomly associated with rare
species (Hegde & Ellstrand, 1999) too, and as fruit type can be
correlated with sex system and habit (reviewed in Gross, 2005)
fundamental life-history characters such as habit, life span, sex
system and fruit type should not be examined in isolation from
each other.
We use the information on life-history characters to describe
first the composition of the Australian flora and then patterns
in trait distribution. Next we determine the utility of
taxon richness as a predictor of extinction (see Schwartz &
monoecious species than expected by chance among the tree species listed as
endangered but fewer among the herbaceous life forms. Threat category was
found to be non-randomly clustered in some clades.
Main conclusions Life-history characters in certain combinations are predictive
of extinction risk. Phylogeny is also an important component of extinction risk.
We suggest that specific life-history characters could be used for conservation
planning and as an early warning sign for detecting vulnerability in lists of species.
Keywords
Australia, correlated evolution, extinction risk, flora, fruit types, genus size, life-
history characters, phylogenetic analyses, sex systems.
A. Sjo¨stro¨m and C. L. Gross
272
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ª 2006 The Authors. Journal compilation ª 2006 Blackwell Publishing Ltd
Simberloff, 2001). Finally we compare our results for the
Australian continent with other regions and provide informa-
tion that could be incorporated into conservation planning.
M A T E R I A L A N D M E T H O D S
The number of extant, endangered and extinct flora
in Australia
Extant flora
To begin we compiled a list of the flowering plant families for
Australia (n
¼ 222 families) and determined the number of
species in each family by consulting Hnatiuk (1990), and,
when it became available, the online version, the Australian
Plant Name Index: http://www.anbg.gov.au/cgi-bin/apni. We
checked the number of species and revised the counts when
more recent treatments became available, for example from the
Flora of Australia volumes, regional floras, or other taxonomic
treatments. Family names were ultimately delineated following
the Angiosperm Phylogeny Group classification (Stevens, 2001
onwards).
Endangered and extinct flora
There is much discussion about the membership and
robustness of threatened species lists (Akcakaya et al., 2000;
Burgman, 2002; Possingham et al., 2002; Keith & Burgman,
2004). Our list of extinct and endangered species was derived
from the schedules within the Environmental Protection and
Biodiversity Act 1999 (EPBC Act) as of November 2003.*
This group of species was considered by us to represent
species most likely to be extinct or to go extinct in the next
10–20 years. We refer to these species as rare because they
variously occur within the seven forms of rarity as proposed
by Rabinowitz (1981). There are many thousands more
species considered as rare in threatened species classifications
in Australia (e.g. Briggs & Leigh, 1996), but these are
generally not considered to be at a high risk of extinction in
the next 10 years and are not considered separately in this
study.
To verify the accuracy of Australian taxa listed as presumed
extinct, we sought collection and taxonomic information for
61 taxa. In particular, an attempt was made to find the
protologue, additional descriptive material, and the most
recent sighting or collection date for each taxon presumed
extinct. Only flowering species were considered.
We then only listed a species as extinct if (1) it was
taxonomically distinct (if the species is known only from a
single specimen, it was placed in the ‘known only from the
type’ category and not considered further), (2) no collections
or sightings of the species are known within the last 50 years,
and (3) the species is not extant outside Australia.
No additional checking was performed on the validity of
membership on the endangered list except to exclude non-
vascular taxa and taxa below the species level or to revise a
name according to the latest systematic information.
Life-history characters
In order to develop a set of testable hypotheses for investi-
gating the significance of the trends observed within the extinct
and endangered flora, against the extant flora as a whole, we
assayed four life-history characters for 31 extinct species, 450
endangered species and for the Australian angiosperms, which
totalled 18,821 species (including 1997 introduced species).
We only included taxa at the species level. We looked at four
life-history characters for each family: habit, life span, sex
system and fruit type. Habit (i.e. life form) was categorized as
herb, vine, liane, shrub, or tree. Life span was categorized as
either short-lived (i.e. annuals or biennials) or long-lived
(perennials). Sex system was categorized as hermaphroditic
(i.e. all flowers bisexual on a plant), dioecious (i.e. female and
male flowers found on separate individuals and includes
andro- and gynodioecious species), or monoecious (i.e. female
and male flowers found as separate flowers on the same
individual and includes andro- and gynomonoecious and
polygamomonoecious species). Fruit type was categorized as
dry-indehiscent (including achene, caryopsis, nut, nutlet,
samara, some schizocarps, utricle, and some capsules), dry-
dehiscent (including most capsules, stroboli, follicles, legume,
mericarp, saliqua, most schizocarps, and loments), or fleshy
(including berry, drupe, gyconium, pome, pseudocarp, spathe,
synangium, syncarp, viviparous seedlings, pipo, and pyrene).
When all species within a family shared the same combi-
nation of life-history characters (see below), the data were
tallied at the family level for the number of species known to
occur in the family. For example, if all species within a family
were hermaphroditic, annual, herbs with capsules, the char-
acter data were tallied along with a count for the number of
species in the family and individual species were not looked at
in detail. For families where categories varied within a life-
history character (e.g. some species were hermaphroditic and
other were dioecious), we looked at the life-history characters
at the generic level and if these were consistent we tallied them;
otherwise, we examined life-history characters for each indi-
vidual species. To determine which category within a character
a species exhibited, we sourced the information in the first
instance either from the Flora of Australia volumes, or from
Morley & Toelken (1983), or from regional botanical reference
texts (a list is available from the authors). If we were not able
to obtain the information from these sources, we gathered and
queried information from published taxonomic treatments,
researchers, protologues or herbarium specimens. For some
species we were unable to determine every life-history char-
acter. In these cases we omitted from the analyses that life-
history character for that species (habit data were lacking for
129 spp., life span for 135 spp., sex system for 192 spp., and
fruit type for 34 spp.).
*The current EPBC Act list is available online at http://www.deh.
gov.au/biodiversity/threatened/species/index.html.
Life-history characters in the Australian flora
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Statistical analyses
Life-history characters
Prior to comparative analysis of the non-endangered extant and
endangered species, introduced species were excluded. Of the
remaining species, each was coded individually according to its
life-history characters and conservation status (i.e. non-
endangered extant or endangered). Owing to the autocorrela-
tion of habit and life span, only the characters habit, sex, and fruit
type were considered. Analysis then proceeded with the follow-
ing steps. The R statistical package (Ihaka & Gentleman, 1996)
was used to obtain contingency tables of each separate character
and conservation status. For example, a table was constructed
of counts of species classified by habit (5 categories) and
conservation status (endangered or non-endangered extant).
For each character and status combination, a G-test (that used a
log-linear model) was performed to test the null hypothesis that
the two factors (i.e. individual characters and status) were
independent in their effects on count (Crawley, 2003).
Next, characters were considered together in a four-way
frequency table (i.e. all character combinations and status). To
model the data, conservation status (endangered or non-
endangered extant) was reformulated as a proportion for ease
of analysis (Crawley, 2003). A GLM (generalized linear model)
with a logit link and binomial error distribution was constructed
with the proportion of taxa as endangered as the response
variable and the habit, sex and fruit-type characters as explan-
atory terms. The saturated model consisted of the main effects,
all two-way interactions, and the three-way interaction of
explanatory terms. The saturated model was reduced by stepwise
removal of terms that reduced the Akaike Information Criterion
(AIC; Akaike, 1974).
A similar procedure was followed to compare extant species
and extinct species. As above, introduced species were
excluded from the analysis. R was used to obtain a four-way
frequency table. The response y (extinct or extant) was
reformulated as a proportion for ease of analysis. A saturated
GLM model with a logit link and binomial error distribution
was constructed with the proportion of taxa extinct as the
response variable, and the main effects, all two-way interac-
tions, and the three-way interactions as explanatory terms.
This model was reduced using the step function in R.
In a separate approach we investigated patterns across status
levels of non-endangered extant, endangered, and extinct
species using a multinomial model (Venables & Ripley, 2002)
that was fitted to the data with the response y as the
conservation status level (extinct, endangered, or non-
endangered extant) and explanatory terms as the life-history
characters. As for the GLM models, the step function in R was
used to reduce the saturated model.
Species richness
We examined whether or not species-poor genera were more
likely to contain threatened or extinct species than species-rich
genera. We excluded genera that only contained introduced
species (n
¼ 660). For each genus (n ¼ 1978), we determined
the proportion that was endangered or extinct relative to the
overall size of the genus in Australia. R was used to investigate
the influence of generic species richness on membership in the
extinct species list. A GLM with a binomial error distribution
and logit link function was constructed to obtain a weighted
regression on the proportion of extinct species within a genus
versus the log of the size of the genus. Similarly, a weighted
regression was also performed on the proportion of endan-
gered species versus the log of the size of the genus. In both
cases, the significance of the parameter values was assessed by a
deletion test in which the original model was compared with a
simpler model that was fitted with a constant (i.e. the null
model).
For both the extinct and endangered species data we
explored the relationship with rarity further by using a second
model that was constructed to include only those genera that
contained extinct species (n
¼ 26) or endangered species
(n
¼ 179), respectively. The reliability of the parameters
estimated for the latter was assessed using a bootstrap test.
The procedure followed was to construct a model that used the
original endangered proportion data as the response variable.
The explanatory term was the log of the size of the genus, and
the number of genera considered consisted of a random
sample (n
¼ 179) of all genera. A weighted regression was
performed on each of 10 000 different random samples and the
resulting parameter values compared.
We repeated the procedure above to investigate familial
speciosity and the presence of endangered or extinct species. In
particular, we excluded families that contained only intro-
duced species (n
¼ 20). For each family (n ¼ 202), we
determined the proportion of taxa that was endangered or
extinct relative to the overall size of the family in Australia. A
GLM with a binomial error distribution and logit link function
was constructed to obtain a weighted regression on the
proportion of extinct species within a family versus the log of
the size of the family. Similarly, a weighted regression was also
performed on the proportion of endangered species versus the
log of the size of the family. In both cases, the significance of
the parameter values was assessed by a deletion test in which
the original model was compared with a simpler model that
was fitted with a constant (i.e. the null model).
For both the extinct and endangered species data, a second
model was constructed by including only those families that
contained extinct species (n
¼ 16) or endangered species
(n
¼ 62), respectively. The reliability of the parameters
estimated for the latter was assessed using a bootstrap test as
described previously.
The association of rarity with phylogeny
A supertree of the Australian flowering species was too large to
work with and so three smaller trees (Asterids, Core Eudicots
and Commelinids) were constructed using the Phylomatic
database (Webb & Donoghue, 2002), an automated process
A. Sjo¨stro¨m and C. L. Gross
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ª 2006 The Authors. Journal compilation ª 2006 Blackwell Publishing Ltd
that builds a hypothetical tree based on a master phylogeny –
we chose the angiosperm supertree from Davies et al. (2004),
which is based on 46 source trees, as our master phylogeny.
Genera were used as terminal taxa in this analysis because of
the large number of poorly understood infra-generic lineages
and as an attempt to minimize non-independence among
related groups. Insufficient information on relationships
between or within taxa is presented as polytomies. Branch
lengths were not known for all relationships and were given
unit length. A nexus version of these trees is available on
request.
The trait, not threatened or threatened (endangered or
extinct), was traced as a binary character over each tree using
macclade
version 4.03 (Maddison & Maddison, 2001). Thus
genera containing an endangered or extinct species were given
a score of 1 while genera without an endangered or extinct
species were given a score of 0. Clustering of the trait
(phylogenetic conservatism) was examined by determining the
number of steps required for each character state (summed
cost of all changes, gains and losses) in each of the three trees.
Polytomies were set as soft to represent uncertain resolution
and so that the polytomy is resolved in the most parsimonious
way for that character. (Hard polytomies, on the other hand,
assume, for any character exhibited among a group of taxa,
that character has evolved independently for each taxon, i.e.
simultaneous speciation events.) The character state was
reshuffled among the taxa in 1000 random resolutions of each
tree. For each tree, character tracing was then used to compare
the actual number of steps with the number of steps in the
1000 trees based on randomly reshuffling the character states.
If the actual number of steps ranked within the lowest 5% of
the 1000 random resolutions, the character was considered
significantly phylogenetically clustered.
The concentrated-changes test in MacClade version 4.03
(Maddison & Maddison, 2001) was used to examine whether
observed associations among traits (e.g. rarity and genus size)
reflect phylogenetic correlations. This test examines whether
gains (0 to 1 changes in a binary character) in one character
(e.g. extinct status) are more concentrated than expected by
chance on those branches of the tree that are reconstructed to
have a particular distribution of state in the second character
(e.g. genus size). This test can only be used on resolved trees
(i.e. without polytomies), and thus 10 randomly resolved
trees were used so that a range of probabilities could be
reported. Threat status was traced against genus size
[1
¼ small (1–2 species) 0 ¼ or not small] and in a separate
set of analyses against sex systems (unisexual or bisexual) and
against fruit type.
R E S U L T S
Based on the data we collated, the Australian flowering
vascular flora comprises 222 families, 2638 genera and 18,821
species of which c. 10.6% of species are introduced (Table 1).
The geometric mean number of species in a family is
13.55 ± 17.08 (median
¼ 11.5, range 1–2509), and the geo-
metric mean of genera in a family is 4.08 ± 1.94 (median
¼ 3,
range 1–256). We consider that there are only 31 flowering
plant species in Australia that can be unambiguously consid-
ered extinct at the present time (Table 1). The number of
families containing endangered species is 63 (179 genera), and
there are 18 families (27 genera) with extinct species in them.
Most of the species are herbs and shrubs(Fig. 1a), and most
(c. 76%) of the introduced species in Australia are herbs
(Fig. 1a). The majority of species are long-lived (more than
2 years), and introduced species are found equally in both
categories (Fig. 1b). Most species have a bisexual sex system
(Fig. 1c), including introduced species. The predominant fruit
type is dry-dehiscent (Fig. 1d) in both native and introduced
species.
Life-history characters
A comparison of endangered versus extant (native species
only) showed no significant difference in habit (G
¼ 6.13,
P > 0.05, Fig. 2a). However, when habit in extinct species is
compared with that in extant species, trees are significantly
absent from the extinct flora (G
¼ 12.76, P < 0.05, Fig. 2a).
The GLM model for extinct versus extant yielded the model
y
habit
(Wald
¼ 19.86,
P
¼ 0.013,
32%
deviance
explained). A comparison of endangered versus extant for
sex
system
showed
significant
differences
(G
¼ 27.43,
P < 0.001, Fig. 2b), but not in the extinct flora (G
¼ 0.38,
P > 0.05, Fig. 2b). Similarly there were significant differences
in the distribution of fruit types between endangered versus
extant flora (G
¼ 56.47, P < 0.001, Fig. 2c), but not for the
extinct species (G
¼ 0.25, P > 0.05, Fig. 2c).
Stepwise reduction of the saturated GLM model for life
history of endangered versus extant (native only) yielded
y
habit + sex + fruit + habit : sex + habit : fruit. We at-
tempted to reduce the model further by removing the two-way
interactions. An analysis of deviance indicated that removal of
either of these interactions resulted in significant increases in
deviance. Hence these two two-way interactions were kept in the
model. Because neither the contrast for lianes nor for vines was
significant when compared with other habits, we attempted to
reduce the number of levels for habit by lumping lianes with
shrub, and vines with herbs to fit a simpler model. Because the
simpler model had a decreased AIC value and an analysis of
deviance indicated that lumping habit levels did not show a
significant increase in deviance, the simpler model was accepted.
Further attempts to reduce the model by either removing terms
or reducing the number of levels within variables either
increased the AIC, resulted in a significant increase in deviance,
or were not biologically relevant. Thus, the minimum model
accepted is y
habit3 + sex + fruit + habit3 : sex + habit3 :
fruit, where habit3 consists of herbs (including vines), shrubs
(including lianes) and trees (Table 2). The abundance of sex and
fruit types varied significantly between the endangered and the
extant data sets (Table 3). Significant interactions occurred
where habit and sex type and habit and fruit type varied
differently in the endangered data set compared with in the
Life-history characters in the Australian flora
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Table 1 A list of the families, number of genera and species and the percentage of species introduced to Australia. The endangered species
from the EPBC Act (1999) are listed. Where more than one infra-specific taxon is listed only one was included in the analysis. Extinct species
are listed according to rules listed in the text. Family names follow Stevens (2001 onwards)
Family
No. genera
No. spp.
% intro
Endangered
Extinct
Acanthaceae
25
57
17.5
Graptophyllum reticulatum, Isoglossa eranthemoides,
Xerothamnella herbacea
Actinidaceae
1
1
0.0
Agavaceae
6
9
88.9
Aizoaceae
19
61
36.1
Akaniaceae
1
1
0.0
Alismataceae
5
10
60.0
Alseuosmiaceae
2
2
0.0
Amaranthaceae
47
481
8.7
Roycea pycnophylloides, Sclerolaena napiformis
Anacardiaceae
10
14
35.7
Anarthriaceae
2
7
0.0
Annonaceae
19
50
4.0
Apiaceae
41
185
15.1
Eryngium fontanum, Gingidia montana,
Trachymene saniculifolia
Apocynaceae
44
183
9.3
Cynanchum elegans, Ochrosia moorei,
Parsonsia dorrigoensis,
Tylophora linearis, T. rupicola, T. woollsii
Marsdenia araujacea
Aponogetanaceae
1
10
20.0
Aponogeton bullusus, A. proliferus
Aquifoliaceae
2
5
20.0
Araceae
16
39
15.4
Araliaceae
11
46
6.5
Astrotricha roddii
Arecaceae
24
59
5.1
Archontophoenix myolensis, Ptychosperma bleeseri
Aristolochiaceae
2
13
7.7
Asphodelaceae
2
5
100.0
Asteraceae
256
1121
21.9
Argentipallium spiceri, Brachyscome muelleri,
Calotis moorei, Leucochrysum albicans var.
tricolor, Olearia flocktoniae,
Olearia hygrophila, Olearia microdisca,
Rutidosis leptorrhynchoides, Senecio behrianus
Olearia oliganthema,
Ozothamnus selaginoides,
Picris compacta,
Picris drummondii,
Senecio georgianus
Atherspermaceae
1
1
0.0
Austrobaileyaceae
1
2
0.0
Balanopaceae
1
1
0.0
Balanophoraceae
1
2
0.0
Balsaminaceae
1
1
100.0
Basellaceae
1
1
100.0
Bataceae
1
1
0.0
Berberidaceae
2
3
100.0
Betulaceae
1
1
100.0
Bignoniaceae
12
19
36.8
Bixaceae
2
4
25.0
Blandfordiaceae
1
4
0.0
Boraginaceae
26
156
19.9
Brassicaceae
60
195
37.9
Ballantinia antipoda, Barbarea
australis, Irenepharsus trypherus,
Lepidium hyssopifolium,
L. monoplocoides, L. peregrinum
Lepidium drummondii
Bromeliaceae
2
2
100.0
Burmanniaceae
2
4
0.0
Burmannia sp. Melville Island
(R. Fensham 1021)
Burseraceae
2
5
0.0
Byblidaceae
1
2
0.0
Cabombaceae
2
2
50.0
Cactaceae
7
23
100.0
Calycanthaceae
1
1
0.0
Campanulaceae
9
64
6.3
Hypsela sessiliflora
A. Sjo¨stro¨m and C. L. Gross
276
Journal of Biogeography 33, 271–290
ª 2006 The Authors. Journal compilation ª 2006 Blackwell Publishing Ltd
Table 1 continued
Family
No. genera
No. spp.
% intro
Endangered
Extinct
Cannabaceae
2
2
100.0
Cannaceae
1
1
100.0
Caprifoliaceae
4
8
75.0
Cardiopteridaceae
1
1
0.0
Caricaceae
1
1
100.0
Caryophyllaceae
24
83
62.7
Sagina diemensis
Casuarinaceae
3
64
0.0
Allocasuarina defungens, A. emuina,
A. glareicola, A. portuensis, A. thalassoscopica
Celastraceae
19
57
0.0
Apatophyllum constablei
Centrolepidaceae
3
31
0.0
Centrolepis caespitosa
Cephalotaceae
1
1
0.0
Ceratophyllaceae
1
2
0.0
Chrysobalanaceae
2
2
0.0
Cistaceae
1
1
100.0
Clusiaceae
6
23
17.4
Colchicaceae
8
47
4.3
Wurmbea calcicola, W. tubulosa
Combretaceae
6
36
2.8
Commelinaceae
11
35
22.9
Connaraceae
2
2
0.0
Convolvulaceae
20
119
16.8
Cornaceae
1
2
0.0
Corsiaceae
1
1
0.0
Corynocarpaceae
1
2
0.0
Costaceae
2
3
0.0
Crassulaceae
6
29
71.4
Cucurbitaceae
18
43
27.9
Mukia sp. Longreach (D.Davidson AQ279935)
Cunoniaceae
16
35
0.0
Davidsonia jerseyana, D. johnsonii
Cymodoceaceae
5
10
0.0
Cyperaceae
45
682
6.6
Cyperus cephalotes, Fimbristylis adjuncta,
Lepidosperma rostratum
Datiscaceae
1
1
0.0
Dichapetalaceae
1
1
0.0
Dilleniaceae
5
140
0.0
Dioscoreaceae
2
7
0.0
Dipsacaeae
2
4
100.0
Doryanthaceae
1
2
0.0
Droseraceae
2
55
0.0
Ebenaceae
1
15
0.0
Diospyros mabacea
Elaeagnaceae
1
1
0.0
Elaeocarpaceae
9
88
0.0
Elaeocarpus sp. Rocky Creek (G.Read AQ562114),
E. williamsianus, Tetratheca deltoidea, T. gunnii,
T. paynterae
Tetratheca fasciculata
Elatinaceae
2
8
0.0
Ericaceae
35
433
1.8
Andersonia axilliflora, A. gracilis, Epacris acuminate,
E. apsleyensis, E. barbata, E. exserta, E. grandis,
E. hamiltonii, E. limbata, E. sp. aff. virgata ‘graniticola’,
E. stuartii, Leucopogon confertus, L. gnaphalioides,
L. marginatus, L. obtectus, L. sp. Coolmunda
(D.Halford Q 1635), Melichrus hirsutus J.B.Williams ms.,
M. sp. Gibberagee (A.S.Benwell & J.B.Williams 97239)
Leucopogon cryptanthus
Eriocaulaceae
1
26
0.0
Eriocaulon australasicum, E. carsonii
Erythroxylaceae
1
4
0.0
Euphorbiaceae
52
278
12.2
Bertya ingramii, B. sp. Beeron Holding (P.I.Forster 5753),
Beyeria lepidopetala, Fontainea oraria,
Ricinocarpos trichophorus
Sankowskya stipularis
Amperea xiphoclada
var. pedicillata
Eupomatiaceae
1
2
0.0
Life-history characters in the Australian flora
Journal of Biogeography 33, 271–290
277
ª 2006 The Authors. Journal compilation ª 2006 Blackwell Publishing Ltd
Table 1 continued
Family
No. genera
No. spp.
% intro
Endangered
Extinct
Fabaceae
176
2509
7.7
Acacia aprica, A. aristulata, A. ataxiphylla subsp. magna,
A. auratiflora, A. brachypoda, A. cochlocarpa subsp.
cochlocarpa, A. cretacea, A. enterocarpa, A. gordonii,
A. insolita subsp. recurva, A. lanuginophylla, A. leptalea,
A. lobulata, A. pharangites, A. pinguifolia, A. porcata,
A. pygmaea, A. recurvata, A. rhamphophylla, A. ruppii,
A. sciophanes, A. shirleyi, A. sp. Dandaragan
(S. van Leeuwen 269), A. subflexuosa subsp. capillata,
A. terminalis subsp. terminalis, A. vassalii, A. volubilis,
A. whibleyana, Cajanus mareebensis, Chorizema humile,
Chorizema varium, Cullen parvum, Daviesia bursarioides
D. cunderdin, D. euphorbioides, D. megacalyx, D. microcarpa,
D. speciosa, Gastrolobium glaucum, G. graniticum,
G. hamulosum, Jacksonia pungens J.Chappill ms.,
J. quairading J.Chappill ms., J. sp. Collie (C.J.Koch 177),
Kennedia macrophylla, Pultenaea parris parrisiae subsp. elusa,
Stonesiella (Pultenaea) selaginoides, Swainsona recta
Acacia kingiana,
A. prismifolia,
Indigofera efoliata,
Pultenaea maidenii,
Streblorrhiza speciosa
Fagaceae
1
3
100.00
Flagellariaceae
1
1
0.0
Frankeniaceae
1
47
2.1
Frankenia plicata
Fumariaceae
4
10
100.0
Gentianaceae
8
31
22.6
Gentiana baeuerlenii, G. wingecarribiensis
Geraniaceae
3
34
41.2
Gesneriaceae
5
6
0.0
Goodeniaceae
12
379
0.0
Coopernookia georgei, Lechenaultia laricina, L. pulvinaris
Grossulariaceae
10
27
7.4
Gunneraceae
1
1
0.0
Gyrostemnonaceae
5
18
0.0
Gyrostemon reticulatus
Haemodoraceae
8
74
2.7
Anigozanthos bicolor subsp. minor, Conostylis dielsii subsp.
teres, C. drummondii, C. lepidospermoides, C. micrantha,
C. misera, C. seorsiflora subsp. trichophylla, C. setigera
subsp. dasys, C. wonganensis
Haloragaceae
6
105
0.0
Haloragis eyreana, Haloragodendron lucasii,
Myriophyllum lapidicola
Haloragis platycarpa
Hamamelidaceae
3
3
0.0
Hanguanaceae
1
1
0.0
Hemerocallidaceae
1
1
0.0
Hernandiaceae
3
6
0.0
Himantandraceae
1
1
0.0
Hydatellaceae
2
7
0.0
Hydatella dioica
Hydrocharitaceae
13
28
10.7
Hypoxidaceae
1
10
0
Icacinaceae
6
7
0.0
Iridaceae
32
95
69.5
Orthrosanthus muelleri, Patersonia spirafolia
Juncaceae
2
74
27.0
Juncaginaceae
3
16
6.3
Lamiaceae
44
293
16.0
Hemiandra gardneri, H. rutilans, H. sp. Watheroo
(S.Hancocks 4), Plectranthus habrophyllus, P. nitidus,
P. omissus, P. torrenticola rostanthera askania, P. eurybioides,
P. junonis, Westringia crassifolia, W. kydrensis
Prostanthera albo-hirta,
P. marifolia
Lauraceae
9
131
1.5
Endiandra cooperana, E. floydii
Laxmanniaceae
3
107
0.0
Lecythidaceae
2
5
0.0
Lentibulaniaceae
1
61
1.6
Liliaceae
55
180
24.4
Borya mirabilis, Dianella amoena
Limnocharitaceae
2
2
50.0
A. Sjo¨stro¨m and C. L. Gross
278
Journal of Biogeography 33, 271–290
ª 2006 The Authors. Journal compilation ª 2006 Blackwell Publishing Ltd
Table 1 continued
Family
No. genera
No. spp.
% intro
Endangered
Extinct
Linaceae
1
7
71.4
Loganiaceae
9
101
1.0
Loranthaceae
12
69
0.0
Amyema scandens
Luzuriagaceae
1
2
0.0
Lythraceae
10
29
17.2
Malpighiaceae
2
2
0.0
Malvaceae
61
471
7.0
Corchorus cunninghamii, Lasiopetalum pterocarpum
E.M.Benn & K.Shepherd ms., L. rotundifolium, Rulingia prostrata,
Rulingia sp. Trigwell Bridge (R.Smith s.n. 20/6/1989),
Thomasia sp. Green Hill (S.Paust 1322)
Melastomataceae
5
8
12.5
Meliaceae
12
41
2.4
Melianthaceae
1
2
100.0
Memecylaceae
1
3
0.0
Menispermaceae
11
18
0.0
Carronia pedicellata
Menyanthaceae
3
30
0.0
Villarsia calthifolia
Molluginaceae
3
13
0.0
Macarthuria keigheryi
Monimiaceae
12
35
0.0
Daphnandra sp. Illawarra (R.Schodde 3475)
Moraceae
10
46
4.3
Moringaceae
1
1
100.0
Musaceae
1
3
0.0
Musa fitzalanii
Myoporaceae
2
248
0.0
Eremophila denticulata subsp. trisulcata Chinnock ms.,
E. nivea, E. pinnatifida Chinnock ms., E. resinosa,
E. scaberula, E. ternifolia, E. veneta Chinnock ms.,
E. verticillata, E. virens, Myoporum turbinatum
Myristicaceae
2
3
0.0
Myrsinaceae
7
34
5.9
Rapanea sp. Richmond River (J.H.Maiden & J.L.Boorman NSW 26751)
Myrtaceae
77
1593
0.4
Austromyrtus fragrantissima, Austromyrtus gonoclada, Baeckea kandos,
Calytrix breviseta subsp. breviseta, Chamelaucium sp. Gingin
(N.G.Marchant s.n. 4/11/1988), Darwinia acerosa, D. apiculata,
D. carnea, D. chapmaniana Marchant & Keighery ms., D. collina,
D. ferricola N.G.Marchant & Keighery ms., D. oxylepis,
D. sp. Carnamah (J.Coleby-Williams 148), D. sp. Williamson
(G.J.Keighery 12717), D. wittwerorum, Decaspermum sp. Mt Morgan
(D.Hoy 71), Eucalyptus absita, E. balanites, E. beardiana, E. bennettiae,
E. brevipes, E. burdettiana, E. conglomerata, E. copulans, E. crenulata,
E. crucis subsp. praecipua, E. cuprea, E. dolorosa,
E. graniticola Brooker & Hopper ms., E. gunnii subsp. divaricata,
E. imlayensis, E. impensa, E. insularis, E. leprophloia, E. morrisbyi,
E. pachycalyx subsp. banyabba, E. phylacis, E. pruiniramis, E. recurva,
E. rhodantha var. petiolaris, E. sp. Howes Swamp Creek
(M.Doherty 19/7/1985 NSW 207054), Hypocalymma longifolium,
Micromyrtus grandis, Triplarina imbricata, Triplarina nowraensis,
Uromyrtus australis, Verticordia albida, V. densiflora var. pedunculata,
V. fimbrilepis subsp. fimbrilepis,V. harveyi,V. hughanii, V. pityrhops,
V. plumosa var. ananeotes, V. plumosa var. pleiobotrya,
V. plumosa var. vassensis, V. spicata subsp. squamosa,
V. staminosa subsp. cylindracea var. cylindracea,
V. staminosa subsp. staminosa, Xanthostemon formosus
Nelumbonaceae
1
1
0.0
Nepenthaceae
1
1
0.0
Nothofagaceae
1
3
0.0
Nyctaginaceae
5
15
13.3
Nymphaeceae
2
13
30.8
Ochnaceae
2
2
50.0
Olacaceae
3
13
0.0
Oleaceae
9
30
20.0
Life-history characters in the Australian flora
Journal of Biogeography 33, 271–290
279
ª 2006 The Authors. Journal compilation ª 2006 Blackwell Publishing Ltd
Table 1 continued
Family
No. genera
No. spp.
% intro
Endangered
Extinct
Onagraceae
5
37
54.1
Opiliaceae
2
2
0.0
Orchidaceae
105
862
0.3
Arthrochilus huntianus subsp. nothofagicola, Caladenia
(listed as Drakonorchis) drakeoides Hopper & A.P.Brown ms.,
C. amoena, C. anthracina, C. arenaria, C. argocalla, C. atroclavia,
C. audasii, C. behrii, C. bryceana subsp. bryceana, C. busselliana
Hopper & A.P.Brown ms., C. caesarea subsp. maritima, C. campbellii,
C. carnea var. subulata, C. colorata, C. dienema, C. dorrienii, C. elegans
Hopper & A.P.Brown ms., C. excelsa Hopper & A.P.Brown ms.,
C. fragrantissima subsp. orientalis, C. fulva, C. gladiolata, C. hastata,
C. hoffmanii Hopper & A.P.Brown ms., C. huegelii Hopper &
A.P.Brown ms., C. lindleyana, C. lowanensis, C. macroclavia, C. pallida,
C. richardsiorum, C. rigida, C. robinsonii, C. rosella, C. saggicola, C. sp. aff.
venusta, C. sylvicola, C. tensa, C. thysanochila, C. tonellii, C. viridescens
Hopper & A.P.Brown ms., C. winfieldii Hopper & A.P.Brown ms.,
C. xanthochila, C. xantholeuca, Calochilus psednus, C. richiae, Corybas sp.
Finniss (R.Bates 28794), Crepidium lawleri, Dendrobium antennatum,
D. lithocola, D. mirbelianum, D. nindii, Dipodium pictum, Diuris basaltica
D.L. Jones ined., D. fragrantissima, D. lanceolata, D. pedunculata,
D. purdiei, Drakaea confluens Hopper & A.P.Brown ms., D. elastica,
D. isolata Hopper & A.P.Brown ms., Epiblema grandiflorum var. cyanea
K.Dixon ms., Genoplesium brachystachyum, G. firthii, G. plumosum,
G. rhyoliticum, G. tectum, Habenaria macraithii, Microtis angusii,
Paracaleana dixonii Hopper & A.P.Brown ms., Phaius australis,
P. bernaysii, Phaius tancarvilleae, Phalaenopsis rosenstromii, Prasophyllum
affine, P. amoenum, P. apoxychilum, P. castaneum, P. correctum,
P. diversiflorum, P. favonium, P. frenchii, P. milfordense, P. olidum,
P. perangustum, P. petilum, P. pulchellum, P. robustum, P. secutum,
P. stellatum, P. suaveolens, P. subbisectum, P. tunbridgense, P. uroglossum,
Pterostylis aenigma, P. atriola, P. basaltica, P. commutata, P. despectans,
P. gibbosa, P. rubenachii, P. saxicola, P. sp. Botany Bay
(A.Bishop J221/1-13), P. sp. Halbury (R.Bates 8425), P. sp. Hale
(R.Bates 21725), P. sp. Northampton (S.D.Hopper 3349), P. wapstrarum,
P. ziegeleri, Rhizanthella gardneri, Thelymitra epipactoides, T. jonesii,
T. manginii K.Dixon & Batty ms., T. stellata, Vrydagzynea paludosa
Acianthus
ledwardii,
Caladenia
brachyscapa,
C. pumila,
Diplocaulobium
masonii,
Diuris bracteata,
Oberonia
attenuata
Orobanchaceae
1
2
50.0
Oxalidaceae
2
30
73.3
Pandanaceae
2
36
0.0
Pandanus spiralis var. flammeus
Papaveraceae
6
13
100.0
Passifloraceae
2
14
64.3
Pedaliaceae
5
8
50.0
Philydraceae
3
5
0.0
Phyllanthaceae
14
148
2.0
Phytolaccaceae
3
5
80.0
Piperaceae
3
11
9.1
Pittosporaceae
11
88
0.0
Bentleya spinescens, Marianthus (Billardiera) mollis
Plantaginaceae
2
43
27.9
Plumbaginaceae
4
11
63.6
Poaceae
234
1299
23.9
Agrostis adamsonii, A. limitanea, A. granitica, Austrostipa wakoolica,
Danthonia popinensis, Deyeuxia appressa, D. drummondii,
Digitaria porrecta, Eremochloa muricata, Glyceria drummondii
Amphibromus
whitei
Podostemaceae
2
2
0.0
Polemoniaceae
3
4
75.0
Polygalaceae
6
45
11.1
Polygonaceae
11
54
42.6
Muehlenbeckia tuggeranong
Pontederiaceae
3
6
33.3
Portulacaceae
9
59
8.5
A. Sjo¨stro¨m and C. L. Gross
280
Journal of Biogeography 33, 271–290
ª 2006 The Authors. Journal compilation ª 2006 Blackwell Publishing Ltd
Table 1 continued
Family
No. genera
No. spp.
% intro
Endangered
Extinct
Posidonaceae
1
8
0.0
Potamogetonaceae
4
19
5.3
Primulaceae
4
10
30.0
Proteaceae
46
1007
0.0
Adenanthos cunninghamii, A. dobagii, A. eyrei, A. pungens subsp.
effusus, A. velutinus, Banksia brownii, B. cuneata, B. oligantha,
Conospermum densiflorum subsp. unicephalatum, Conospermum toddii,
Dryandra anatona, D. aurantia, D. ionthocarpa, D. mimica, D. montana,
D. nivea subsp. uliginosa, Eidothea hardeniana, Grevillea acanthifolia
subsp. paludosa, G. althoferorum, G. batrachioides, G. beadleana,
G. caleyi, G. calliantha, G. christineae, G. curviloba subsp. curviloba,
G. curviloba subsp. incurva, G. dryandroides subsp. dryandroides,
G. dryandroides subsp. hirsuta, G. guthrieana, G. humifusa, G. iaspicula,
G. infundibularis, G. involucrata, G. maccutcheonii, G. masonii,
G. maxwellii, G. mollis, G. molyneuxii, G. murex, G. obtusiflora, G. pythara,
G. rara, G. rivularis, G. scapigera, G. wilkinsonii, G. williamsonii, Hakea
dohertyi, H. pulvinifera, Isopogon uncinatus, Lambertia echinata subsp.
echinata, L. echinata subsp. occidentalis, L. fairallii, L. orbifolia, Lomatia
tasmanica, Macadamia jansenii, Persoonia hirsuta, P. micranthera, P. mollis
subsp. maxima, P. nutans, Petrophile latericola Keighery ms., Synaphea
quartzitica, Triunia robusta
Persoonia
laxa,
P. prostrata
Putranjivaceae
1
4
0.0
Rafflesiaceae
1
2
0.0
Ranunculaceae
9
67
20.9
Ranunculus prasinus
Resedaceae
1
4
100.0
Restionaceae
35
119
0.0
Chordifex (Restio) abortivus
Rhamnaceae
18
165
1.8
Pomaderris cotoneaster, Spyridium microphyllum, Spyridium sp.
(Little Desert), Stenanthemum pimeleoides
Rhipogonaceae
1
5
0.0
Rhizophoraceae
4
12
0.0
Rosaceae
22
82
76.8
Rubiaceae
49
248
6.9
Randia moorei
Rutaceae
46
397
1.3
Acronychia littoralis, Asterolasia elegans, Boronia capitata subsp. capitata,
B. exilis, B. granitica, B. repanda, B. revoluta, Correa lawrenceana var.
genoensis, Drummondita ericoides, Leionema equestre, L. lachnaeoides,
Phebalium daviesii, Philotheca basistyla, P. freyciana, P. wonganensis,
Zieria adenophora, Z. baeuerlenii, J.A.Armstrong ms., Z. buxijugum
J.Briggs & J.A.Armstrong ms., Z. covenyi J.A.Armstrong ms., Z. floydii
J.A.Armstrong ms., Z. formosa J.Briggs & J.A.Armstrong ms.,
Z. granulata, Z. ingramii J.A.Armstrong ms., Z. lasiocaulis J.A.Armstrong
ms., Z. obcordata, Z. parrisiae J.Briggs & J.A.Armstrong ms., Z. prostrata
J.A.Armstrong ms., Z. sp. Brolga Park (A.R.Bean 1002)
Philotheca
falcatus
Salicaceae
11
31
29.0
Santalaceae
13
61
0.0
Spirogardnera rubescens
Sapindaceae
33
200
2.5
Alectryon ramiflorus, Atalaya collina, Cossinia australiana,
Diploglottis campbellii, Dodonaea subglandulifera, Toechima pterocarpum
Sapotaceae
7
29
0.0
Pouteria (Planchonella) eerwah
Saxifragaceae
1
1
0.0
Scrophulariaceae
51
170
30.0
Euphrasia collina subsp. muelleri, E. collina subsp. osbornii, E. fragosa,
E. gibbsiae subsp. psilantherea, E. semipicta, E. sp. ‘fabula’,
Microcarpaea agonis, Stemodia haegii
Euphrasia
arguta
Simaroubaceae
4
9
11.1
Quassia sp. Mooney Creek (J.King s.n. 1949)
Smilaceae
3
9
0.0
Solanaceae
23
210
24.3
Cyphanthera odgersii subsp. occidentalis, Symonanthus bancroftii
Sparganiaceae
1
2
50.0
Sphenocleaceae
1
1
0.0
Stemonaceae
1
4
0.0
Life-history characters in the Australian flora
Journal of Biogeography 33, 271–290
281
ª 2006 The Authors. Journal compilation ª 2006 Blackwell Publishing Ltd
extant data set (Fig. 3, Table 3), notably in the herbaceous life
form.
Stepwise reduction of the multinomial model comparing
endangered, extinct and extant species yielded y
habit +
sex + fruit + habit : fruit. As for the GLM model for the
endangered species, the model was further reduced by lumping
the habit categories of herbs with vines, and shrubs with lianes.
This simpler model had a reduced AIC, and an anova
comparing the two models showed no significant increase in
deviance (LR
¼ 12.66, d.f. ¼ 12, P > 0.05).
Species richness
When the abundance of endangered species was examined
across the 1978 native genera, most of them contained no
endangered species. The GLM regression of proportion of
endangered to the log of the size of genus was highly significant
(odds ratio
¼ 1.131 with 95% confidence interval (CI) 1.099–
1.163, t
¼ 4.37, P < 0.001; G
2
¼ 19.17, d.f. ¼ 1, P < 0.001,
Fig. 4a), showing that species-rich genera are proportionately
more likely to contain endangered species than species-poor
genera. These results are not surprising: the bigger the genus
the more likely it will be that it will contain an endangered
species. When only those genera containing an endangered
species were examined (n
¼ 179), endangered species are more
likely to occur in small genera (odds ratio
¼ 0.619 with 95%
CI 0.596–0.643, t
¼
)7.17; G
2
¼ 169.53, d.f. ¼ 1, P < 0.001,
Fig. 4c). However, because most genera are small in the
Australian flora we queried whether this relationship would
hold irrespective of which genera are used in the analyses. If a
significant relationship between genus size and the proportion
of endangered species can be detected using a random sample
of all genera it would indicate that endangered species are
occurring in small genera in a random way. This was tested
using a bootstrap test on a model with the original endangered
proportion data as the response variable and the log of the size
of the genus as the explanatory term. A weighted regression
was performed on each of 10 000 different random samples
(n
¼ 179). Of the resulting P values, only 2945 were ‡ 0.05.
This strongly suggests that endangered species only occur in
small genera because most genera in Australia are small. Most
genera do not have extinct species, but no significant
relationship was found against genus richness (t
¼
)0.18;
G
2
¼ 0.61, d.f. ¼ 1, P ¼ 0.43, Fig. 4b). When only those
genera containing an extinct species were examined (n
¼ 27),
a significant relationship was found whereby small genera are
more likely to contain extinct species than larger genera (odds
ratio
¼ 0.365
with
95%
CI
0.318–0.420,
t
¼
)7.24;
G
2
¼
)61.54, d.f. ¼ 1, P < 0.001, Fig. 4d).
Only 33% of families contained at least one endangered or
extinct species. Similarly, the relationship between threat status
and family speciosity showed that highly species-rich families
are more likely to contain endangered species than species-poor
families (odds ratio
¼ 1.139 with 95% CI 1.073–1.209,
t
¼ 2.18; G
2
¼ 14.5, d.f. ¼ 1, P ¼ 0.03). A significant rela-
tionship between species richness in families and extinct species
was not found (t
¼ 0.51; G
2
¼ 0.26, d.f. ¼ 1, P ¼ 0.61). When
only those families containing an endangered species were
Table 1 continued
Family
No. genera
No. spp.
% intro
Endangered
Extinct
Stylidiaceae
5
241
0.0
Stylidium coroniforme
Surianaceae
4
5
0.0
Symplocaceae
1
15
0.0
Tamaricaceae
1
1
100.0
Theaceae
2
2
50.0
Thymelaceae
10
106
0.9
Pimelea spicata, P. spinescens subsp. spinescens,
P. venosa
Pimelea spinescens subsp.
pubiflora
Trimeniaceae
1
1
0.0
Triuridaceae
1
1
0.0
Tropaeolaceae
1
1
100.0
Typhaceae
1
3
33.3
Ulmaceae
4
10
10.0
Urticaceae
13
25
28.0
Valerianaceae
3
8
87.5
Verbenaceae
28
167
10.8
Pityrodia scabra
Violaceae
5
23
13.0
Vitaceae
7
44
2.3
Winteraceae
2
10
0.0
Xanthorrhoeaceae
9
50
0.0
Xyridaceae
1
20
0.0
Zingiberaceae
9
18
33.3
Zosteraceae
2
4
0.0
Zygophyllaceae
5
55
3.6
Total
2638
18,821
10.60
A. Sjo¨stro¨m and C. L. Gross
282
Journal of Biogeography 33, 271–290
ª 2006 The Authors. Journal compilation ª 2006 Blackwell Publishing Ltd
used in the analyses (n
¼ 62), no significant relationship was
detected (t
¼
)0.68; G
2
¼ 3.24, d.f. ¼ 1, P ¼ 0.5). However,
when only those families containing an extinct species were
used in the analyses, a significant relationship was detected
(odds ratio
¼ 0.538 with 95% CI 0.465–0.621, t ¼
)4.23;
G
2
¼ 14.98, d.f. ¼ 1, P < 0.0001), showing that large families
are less likely to have extinct species than smaller families.
However, to examine this relationship further for family size
and families containing only extinct species we ran another
bootstrap test (see above). Here the results from the weighted
regressions using 10 000 different random samples of families
(n
¼ 16) and the proportion of extinct species were mostly
significant, with 4144 of the 10 000 iterations yielding a P value
‡ 0.05. Thus low family speciosity is an unlikely predictor of
extinction risk.
The association of extinction risk with phylogeny
The distribution of threat status at the generic level was
investigated for 1640 genera in the Australian angiosperm
0
10
20
30
40
50
Herb Vine Liane Shr
ub Tree
% of species
% of species
% of species
All
Extinct
Endangered
0
20
40
60
80
100
Bisexual
Dioecious
Monoecious
0
20
40
60
80
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