Wood Anatomy of Hawaiian and New Guinean Species of Tetramolopium (Asteraceae): Ecological and Systematic Aspects’
Sherwin Carlquist2 and Timothy K Lowrey3
Abstract: Qualitative and quantitative features are reported for five Hawaiian and one New Guinean species of Tetramolopium. Tetrarnolopium hurnile differs from the other Hawaiian species in its numerous narrow vessels, numerous vasicentric tracheids, and wide rays. Although these features are adaptive in the dry alpine localities of T. humile, they would be adaptive also in the remaining species, which are from dry to moderately dry lowland localities. Thus, one can consider these features of T. humile as systematic indicators. The wood of T pumilurn (New Guinea) has distinctive wide, tall rays that may be related to the short stems in this species; T. pumilum has wood more mesornorphic than that of any of the Hawaiian species. Within Hawaiian Tetramolopium, wood anatomy correlates with dryness of habitat. The species of Tetramolopium studied have highly xeromorphic wood in comparison with woods of dicotyledons at large.
Tetramolopium, A GENUS of tribe Astereae humile (Carlquist 1960, 1994). Some Hawai (Hoffmann 1890), has had a varied taxonomic ian Tetramolopium species are extinct or very history (see Lowrey et al. 2001). Cladistic restricted in distribution (Lowrey 1986, analysis of molecular and morphological data 1990), so the assemblage of material in this sets (Lowrey et al. 2001) shows that Tetra study is unlikely to be bettered. The spe molopium is polyphyletic. Most of the species cies referred to Tetramolopium are subshrubs. are nested within Vittadinia, but T vagans Wood of subshrubs is rarely collected or Pedley and, on a different branch, T pumilurn studied anatomically by botanists. Thus, the Mattf. are outgroups of Vittadinia. The Ha availability of the material studied here rep waiian species of the current study all branch resents an unusual opportunity to record in from a single dade. The results of the Low formation on Tetramolopium wood anatomy. rey et al. (2001) analysis will lead to taxo The wood of Tetramolopium is potentially nomic changes. The inclusion of T. pumilunt of interest because the genus has speciated on in this study offers comparisons with the the Hawaiian Islands (11 species, many with wood anatomy of the Hawaiian species. Ob infraspecifically distinct populations). Most viously, study of wood anatomy of the entire Hawaiian taxa are restricted to localities that “Vittadinia group” of genera is desirable. Be qualify as xeric (Lowrey 1986). These habitats cause the species composing this group are represent a diversity of geological and eda geographically widespread in Australia and on phic formations, ranging from alpine cinders Pacific islands and are nonwoody, the species (Haleakala, Maui) to lithified calcareous have not been studied hitherto except for T. dunes (western Moloka’i). Only T lepidotum occurs in moderately mesic sites, west-facing slopes of ridges in the Wai’anae Mountains, O’ahu (Lowrey 1986). Ecological analysis of I Manuscript accepted 17 June 2002. wood anatomy of Tetramolopium is appropri 2 Santa Barbara Botanic Garden, 1212 Mission Can yon Road, Santa Barbara, California 93105. ate in view of the xeric nature of these sites, Department of Biology, University of New Mexico, because wood anatomy sensitively reflects Albuquerque, New Mexico 87131. ecology in Asteraceae (Carlquist 1966). A distinction is attempted here between char acters that represent direct adaptation to Pacific Science (2003), vol. 57, no. 2:171—179 and those that are systematic in © 2003 by University of Hawai’i Press ecology All rights reserved dicators regardless of ecology. The study of
171
here.
follows
that
text the in
comments
with
embedded
stems
softened
of
sections crotome
1
Table
in
given
are
features
Quantitative mi
rotary by obtained were results cessful
suc more Slightly
way. this in obtained were
RESULTS
sections satisfactory some although crotome,
mi
sliding a
on
sectioning
for
objects cult
clear.
are
availability) moisture
(especially
diffi
specimens
Tetramolopium
render
texture
conditions ecological and
means
simple
tween
wood of
brittleness
and size
stem
Small
be
parallels close the
1985),
Hoekman and
study.
for
available
was
collection
Carlquist
1966,
(Carlquist
offered are
gories,
per
specimen
single a
Only
anatomy.
wood of
cate
defined
crudely in
even
data,
ecological
patterns
mature contain
to
sufficient
diameter
where
but
significance,
statistical
have then a
of
were
field
the in
collected specimens
few
cannot
papers
such in
data
quantitative that
a
only
of
samples Wood
field.
the in
lected
say
can
One
followed.
procedure the
is today,
col
was
collections other of
wood
houses;
anatomy
wood
in comparative
papers all
ally
green
Biology
Mexico New
of
University
virtu
in
followed
a procedure
means,
simple
the
in
cultivated
specimens from
derived
was
of
presentation
the
Consequently,
time). in
1000 above
numbered
collections
Lowrey
moment one
any at
functional is
vessels
the
of
Wood
Moloka’i.
Point,
Kaiehu to
of
proportion
what sure
for know not
does
road on
435,
Lowrey WMoloka’i;
m,
30
ridge,
one
then
even
vessels—although
of diameter
small
of
top
1630, Lowrey
Lowrey,
John)
mean to
related is
condition
wood
of
rapidity
(St.
calcisabulorum
var.
Sherif
rockii T.
Guinea;
(e.g.,
means
to
related are
processes
logical
New m,
2900 Edward,
Albert
Mt. to
trail
physio
However, small.
so is studied
mens
main
near
grassland boggv
in
basins
River
speci
of
portions and
specimens
of
number
Sindaba and
Guimu
separating
saddle
from m
limited
the where
justified not
simply is data
200
1546, Lourey
Mattf.,
pumilum T.
O’ahu;
of
manipulation
Statistical section.
single
m,
850
Kaua, Pu’u
of E
ridge
1643, Lozvrey
a from
derived often
were
measurements
O’ahu;
Mountains,
Wai’anae Kaua,
Pu’u
from
derived Data
great.
not is
samples wood
to
leading trail
below
slope
NE-facing 416,
in
population cell a of
uniformity of
degree
Lowrey
lepidotum,
subsp.
Sherif
(Less.)
idotum
the
and
studied
are
populations
cell
limited lep
T.
Maui;
Haleakal,
Trail,
Sands
Sliding
such
because
anatomy
wood on papers
in
424,
Lowrey
Maui;
Haleakalã, of
summit
uncommon are
analyses
Such
readers. some
near
(uc), 8
Hi
Cariquist
haleakalae,
subsp.
by
noted
be will
etc.)
deviation,
standard
Hillebr.
Gray) (A.
humile
T.
O’ahu;
m, 915
(e.g.,
analysis statistical
of kinds of
absence
Ridge,
‘Ohikilolo
1645,
Lowrey
Lowrey,
The
(2001). Cariquist
and
(1950)
Chalk and
(Sherif)
polyphyllurn
var. Sherif
filfbrme
T.
Metcalfe of
usage the
follows which
cheid,”
Hawai’i; m,
1550 Area,
Saddle
1639,
Lowrey
tra
“vasicentric
term the for except
(1964),
Hillebr., Gray) (A.
arenarium
I
indicated):
Nomenclature on
Committee IAWA
the
low
otherwise
unless
at
UNM (collections
follows
fol
Terms etc. 2,
contact in =
vessels of pair
as are
collections the
for
specimens
Voucher
a 1,
vessel solitary a on based a mean as
METHODS calculated was AND MATERIALS grouping Vessel diameter. men
lu mean as measured was diameter Vessel
safranin. with
stained
and
Fluid
Jeffrey’s
with sites. lowland
from
are others
whereas pine
prepared
were
Macerations
(SEM).
croscope al are
I hurnile) (e.g.,
species
some
because
mi
electron
a scanning with
examined
and regimes,
temperature
several to
also but ity,
coated,
sputter
stubs,
aluminum
on
mounted availabil water low
of
degrees
to
adaptation
slides,
clean
between
dried
were
sections probable to primarily
refers
article
this
in
microtome
sliding
Some balsam.
Canada
in “ecological” term
The
cultivation. in ability
xylene, via
slides, on
mounted and
bination
avail water
greater
with features
wood
tative
com
green
a
safranin—fast
with stained
were quanti in change of
degree
the of
indicator
sections
Some
(1982).
Carlquist of
method a credible gives
species two of
collections
the to
according
processed but
paraffin,
in greenhouse-grown and wild-collected both
2003 April SCIENCE PACIFIC 172 Wood Anatomy of Tetramolopium Cariquist and Lowrey 173
TABLE 1 A7ood Features of Tetrarnolopiurn
Species VG VD VM VL FL MR MW ME
T arenariurn 3.90 10 151 118 345 532 4.9 7.9 T.fi1fornie 3.00 19 299 110 343 1,226 4.1 3.1 T humile—wild >10 6 641 102 211 991 8.4 0.9 T. lepidotum 1.66 20 124 92 327 411 3.0 14.8 Wild 2.89 18 275 91 299 558 4.2 6.0 T. purnilum 1.78 20 95 86 280 1,502 6.7 18.1 T. rockii 6.27 11 280 107 305 870 3.4 4.2 Wild 4.65 11 469 137 284 1,025 3.8 3.2 Collections, means 4.89 14 292 105 299 899 4.3 7.3
VG, mean number of vessels per group; VD, mean vessel lumen diameter, pm; VM, mean number of vessels per square milli meter; VL, mean vessel element length, pm; FL, mean libriform fiber length, pm; MH, mean height of multiseriate rays, sm; MW, mean width of multiseriate rays at widest point (number of cells); ME, mesomorphy ratio (vessel diameter times vessel element length divided by vessel number per square millimeter). Collections and methods cited in Materials and Methods; voucher specimens not cited as “wild” are from greenhouse-grown collections and have Lowrev collecnon numbers above 1000.
Qualitative features are reported in the text cotyledons as a whole by Metcalfe and Chalk that follows. (1950). The range in vessel density in Tetra molopium is from 95 to 641 vessels per square millimeter, and if one compares vessel density Quantitative Vessel Features with vessel lumen diameter for the various As seen in transections, vessels in Tetramo species, one finds that these two dimensions lopium are mostly grouped in radial multiples. are close to being inverse. This is most evident in Figures 1 and 4, but The range in mean vessel element length may also be seen in Figure 5 (lower half) in the species studied, 86—118 jim, is very re and Figure 9. The greatest degree of vessel stricted, almost uniform in comparison with grouping occurs in T. humile (Table 1, Fig the range in dicotyledons at large. The mean ures 7, 8). Although wider vessels are readily for dicotyledons at large is 649 jim (Metcalfe evident in T hurnile wood transections (Fig and Chalk 1950). Mean axial diameter of pit ure 7), what appear to be libriform fibers in cavities in vessels is close to 3.0 jim, slightly transection are mostly narrow vessels and va less in some. Vessel wall thickness averages sicentric tracheids, as evident in Figure 8 by close to 2.2 jim in the species studied. the numerous bordered pits (beaded appear ance) on the fibriform elements. The range in vessel grouping from 1.78 to >10 is greater Vessel Morphology than in most groups of dicotyledons. The range in mean lumen diameter in the Perforation plates are exclusively simple. species studied is from 6 jim in T. lepidotum Lateral wall pitting in vessels consists of al (Figure 4) to 20 jim in T. pumilum (Figure 9). ternate circular bordered pits; pit apertures However, the narrowest vessels in the genus are narrowly elliptical. Helical sculpturing is may be found in T. humile (Figure 7), both in absent on vessel walls. Vessels are less com earlier formed secondary xylem and asso monly angular as seen in transection (Figure ciated with wider vessels; such vessels are 1), more commonly rounded (Figures 4, 5, 7, often the same in diameter as libriform fibers. 9, 11). Radially widened vessels are present in The narrowness of vessels in Tetramolopium is T. arenarium (Figure 1), although they are placed in relief by the mean vessel diameter of more nearly circular in outline in the other 99.6 jim (outside diameter) reported for di- species (Figures 5, 7, 9, 11).
pm.
5 3,
scale
=
Figure pm);
10
(divisions 1
=
Figure in
4,
scale 2,
1,
Figures later.
wider
wood,
formed
earliest in
narrow
vessels
showing
transection
4l6), (Lowrey
lepidoturn
subsp.
lepidoturn
T.
4.
photograph.
SEM section,
tangential of cell
ray
from crystals
3,
Rhomboidal
multiseriate. all
are rays
section;
Tangential 2,
line.
out
in
angular
commonly
vessels
1, Transection;
arenarium. T. 1—3.
Tetramolopiurn. of sections Wood 1—4.
FIGURES
4
I
)1
r.
p
li_I 1111111111111 Ij_•jI I1’
liii
______vessels in top half of photograph FiG GRE S 5—8. Wood sections of Tetramolopium. 5—6. T.fihzforme. 5, Transection; large large represent earlywood. 6, Tangential section; rays are tall, narrow. 7—8. T. humile. 7, Lowrey 424, transection; ves rays are sels near top represent earlywood. 8, carlquist H15, tangential section; all cells other than vessels (near left) and very narrow vessels and vasicentric tracheids. Figures 5—8, scale in Figure 1.
the
numerous
more The
2001).
(Carlquist predom
are
cells Ray
1).
(Table lepidotum
grouping
vessel
of
degree
is safety
conductive T. in
except
height
average in
m 500
exceed
conferring
feature
additional
An
1999). al. et
rays
Multiseriate 10).
(Figure
pumilum T.
and
Davis
1994, al.
et
Hargrave
1975,
(Carlquist
8) 7,
(Figures
humile T. in
except
point
widest
occurred
have
embolisms
after
columns
the at
width
in
cells
five than
less
average
water
restoring
in and
embolisms
of
tion
rays
multiseriate
The
rockii). T.
and
fihiforme,
forma the
deterring in
effective to be
ported
T
T. arenarium, in
observed
were
rays
senate
re
features
are
Tetramolopium
in
observed
uni of
number
small (a very
exclusively
most
millimeter)
square per
(numerous
elements
al
rays
multiseriate
of
consist
rays
Vascular
vessel
narrow short, The 1985). Hoekman
and
(Cariquist shrubs desert Rays Californian
of
those than xeromorphy) more of dicative
(in
lower
even
are that
values
finds one
group.
vessel
or
a
vessel
with
contact in
1),
(Table
species
for
Tetramolopium
derived
are
cells few a
only
scanty;
and
vasicentric is
is ratio
this If 1985).
Hoekman
and quist
species all
in
parenchyma
Axial
humile. T. and
Carl
(e.g., nature
arbitrary
apparent
its
spite
arenarium T. in
observed
were
walls lignified
de
ecology,
of indicator
sensitive a
proved
with
cells
parenchyma
axial
Nonsubdivided
has
millimeter)
square per
vessels
of
ber
species.
most in
walls
lignified with
cells of
num
by
divided
length
element
vessel
times
pair a
of consist
parenchynia
axial of
Strands
diameter (vessel Ratio” “Mesomorphy The
Parenchyma Axial
Conclusions Habital and Ecological
left).
12).
11,
(Figures
9,
(Figure
pumilum T.
in
occur
tangentially
T. rockii
especially
and
9),
(Figure
pumilum
wide
unusually are
that fibers
libriform of T
2), 1,
(Figures
T. arenarium
in
vessels to
bands
Radial
septate.
not
are and pits
slitlike
adjacent cells
or
vessels in
observed were
ing)
minute
bear
fibers Libriform
elements.
vessel
stain before
(yellowish
compounds
staining
of
thickness
wall than
im greater
0.2—0.4
Dark- 3).
(Figure
arenarium T. of
cells
ray
is
fibers
libriform of
thickness
Wall studied). a few
in
observed
were
crystals
Rhomboidal
species the
for 3.3 to 2.2 from range types cell
two
the of length in C’ontents ratios C’ellular mean (the ments
ele
vessel than longer appreciably average
fibers
Libriform 8). and 6 Figures
(compare
bottom).
and
humile
T.
than
other
species
the in
wood
center, top, at
bands,
three in
vessels
wide 11,
of
background the
form fibers
Libriform
(Figure rockii T. and bottom), 7, (Figure humile
T.
top), 5, (Figure
fihiforme
T in earlywood
Fibers
Libriform
demarcate vessels Wider 8). (Figure present is
storying vague species, that in humile; T. than
other humile. T species than the in other observed was
storying
No
species in observed not were tracheids
centric
Rings
Grozvth Vasi
Storying; species. this of wood the in elsewhere
patches in occur fibers libriform of numbers
small
although 8, and 7
Figures in shown
lepidotum.
are
fibers
libriform no T
of rays tracheids; in centric observed were
cells
lignified
vasi
termed be
must
thus non and Occasional pits. imperforate simple
small,
bear and
are half
about and
elements, thickness in vessel im narrow 0.3—0.5
about
are
walls
cell
are 8
and 7
Figures
in Ray shown
12). 6, 2, elements the (Figures of common
equally
about
half
About 1994).
1960,
are cells (Carlquist humile procumbent T and
square,
upright,
in
earlier
reported
were
studied, tracheids species other Vasicentric the in but 10), (Figure
pumilum T
and humile T. in upright inantly
Tracheids Vasicentric
2003 April SCIENCE PACIFIC 176 FIGURFS 9—12. Wood sections in Tetramolopiurn. 9—10. T. pumilum. 9, Transection; radial strip of exceptionally wide libriform fibers near left. 10, Tangential section; notably wide ray shown. 11—12. T. rockii var. calcisabulorurn. 11, Transection; dark gray deposits in some vessels and adjacent cells represent oleoresins. 12, Tangential section; most ray cells are upright cells. Figures 9—12, scale in Figure 1.
Tetramo
of
species
Hawaiian
the
in served
paedomor
the
with
consonant
is
molopium
ob
were
cells
ray in
crystals Rhomboidal
in Tetra
cells
upright of
preponderance
or
habitats.
different
into
radiated
that
group
abundance
The species.
this in
rays tall
wide,
the
in
species
other the
in
maintained not
the to
related probably are and
distinctive
features
macromorphological and
anatomical
are
pumilum T. of
stems thick
short,
atively
wood
possesses
apparently
humile
T true,
If
rel The
species.
Hawaiian
the of any
of that
species.
a polymorphic
of
introduction single
than
mesomorphic
more
slightly
is
Guinea,
a
after
sorting phyletic
from
resulted
have New from
pumilum, T.
of
wood
The
may lineage
Hawaiian the
in
versification
features.
wood
quantitative phic
di
evolutionary
that
suggested have (1997)
xeromor
more
had
specimen
field-collected
al. et
Okada
and (1995)
Lowrey
thermore,
the 1),
(Table
compared be
could
species
Fur
lineage.
the in
taxon diverging
early
an
a particular
of
wood
greenhouse-grown a
and
is
humile T
that
suggests taxa
Hawaiian the
a
field-collected
where
However, 1).
(Table
in 1997) al. et (Okada data
RFLP
and 1995)
greenhouse-cultivated
from
derived
(Lowrey
morphology
of
analysis
logenetic
were
specimens
the of
most
that fact
the
Phy
1995).
(Lowrey
lineage
Hawaiian the in
despite mesic to
xeric
from
habitats in
range
autapomorphic
are that
characters
phological
the
parallel data
wood
quantitative the that
mor
several
exhibits also
humile
ramolopium interesting is
It 1986).
(Lowrey
O’ahu tains,
Tet
humile. T.
of
autapomorphies
represent Moun
Wai’anae
m,
600—900 forest,
mesic
may
features
wood these
Therefore,
cies.
of faces
cliff
species,
Hawaiian
any of
cality
spe alpine
just not
species,
lowland in
found
lo
mesomorphic most
the in occurs
which
be
can
genera,
dicotyledonous other in
that,
lepidotum, of T.
that
is studied
species ian
features are
they
the genus, within
adaptive Hawai the
of
wood
mesomorphic
most The
are
humile T.
of
features wood
the
Although
adaptive. are
elements
vessel short
narrow,
genus.
the
within
distinctive as
humile T of
its where
1986),
(Lowrey
Moloka’i
western
achenes
nerved the
to attention
called
(1890)
of dunes sand
lithified
calcareous as the
sites
Hoffmann species.
the of
distinctive most
dry such
in occurs
rockii
Tetramolopium
the as it mark humile T of
tracheids
centric
(1999).
al. et
Davis
vasi
and
vessels narrow
numerous the and by
offered
were
embolisms
freezing-induced
storying
The
concept. this with
consonant
in
function
a similar
suggesting
servations
are
data wood
The
2001). et a!.
Lowrey 1997,
ob
and
(1994), a!.
et
Hargrave by
provided
al.
et
Okada
1995,
(Lowrey
data
molecular
been
have vessels wide
than
better lisms
and
morphological
of
analyses
phylogenetic
embo
drought-induced
resist
vessels
narrow
on
based
monophyletic be
to
thought are
that idea
the
supporting
data
perimental
humile T.
than
other species
Hawaiian The
Ex 1975). (Cariquist tension under itation
cav resist to
hypothesized
been have and
conclusions
Systematic
1966) (Carlquist drought with correlated are
vessels Narrow localities. midelevation
mesic
moist.
steadily
moderately to
lowland dry
from
occur
species
more be to
likely
levels
soil
deeper reach
the of
remainder
The freezing.
and
drought
roots when
conduction)
rapid at
(efficient tive
both
experiences
it
where
habitat
alpine
an
adap
more
are
vessels wider but
soil,
drying
in occurs that
species
Hawaiian
only the
is
readily
shallow,
very in mostly
are roots
when
which hurnile,
T. of that
is
clearly
here studied
safer
conductively are
vessels
narrow
cause woods
the of
xeroinorphic
most
The
be perennials,
herbaceous or
subshrubs in
Asteraceae. of
species
average
finds
often
one a feature
is 4)
(Figure
stem a
the of that
with compared
high
is
I Table
in age
with
diameter
vessel
in
increase The
in shown grouping
vessel
of
degree
The
2001). Carlquist
(see
phylad a
for
ancestry
group. the of
vessels
the
of
many in
broken
woody
strongly
not or
a herbaceous
indicate are
columns
water if
even
maintained
be
can
cells
upright of
proportion
high a
with rays
pathway
conductive a
that
chances the
greater
that
states
which
wood, in
hypothesis
phosis
the group, a vessel within contact in vessels
2003 April SCIENCE PACIFIC 178 Wood Anatomy of Tetramolopium Cariquist and Lowrey 179 lopiurn only in T. arenarium. However, they 1999. The relationship between xylem are not common in material of that species, conduit diameter and cavitation caused by and the sampling of the Hawaiian species was freezing. Am. J. Bot. 86:1367—13 72. of necessity incomplete. Therefore, one can Hargrave, K. R., K. L. Kolb, F. W. Ewers, not cite crystal presence as a specific character and S. D. Davis. 1994. Conduit diameter with certainty. Thoroughness of sampling is and drought-induced embolism in Salvia a much more difficult problem when mate mellifera Greene (Labiatae). New Phytol. rials must be sectioned rather than viewed 126:695—705. with a dissecting microscope, and therefore Hoffman, 0. 1890. Compositae. Pages 88— one should cite anatomical features as char 402 in A. Engler and K. Pranti, eds. Die acteristics of particular species or genera only naturlichen Pflanzenfamilien IV(5). Verlag with reservations. Wilhelm Engelmann, Leipzig. JAWA Committee on Nomenclature. 1964. Multilingual glossary of terms used in ACKNOWLEDGMENTS wood anatomy. Verlabuchanstalt Konkor The assistance provided by a National Sci dia, Winterthur. ence Foundation Grant (DEB-9200578) to Lowrey, T. K. 1986. A biosystematic revision T.K.L. is gratefully acknowledged. of Hawaiian Tetrarnolopiurn (Compositae: Astereae). Allertonia 4:203—265. 1990. Tetramolopiurn. Pages 361—369 Cited Literature in W. L. Wagner, D. R. Herbst, and S. H. Cariquist, S. 1960. Wood anatomy of Aster Sohmer, Manual of the flowering plants eae (Compositae). Trop. Woods Yale of Hawai’i. University of Hawai’i Press, Univ. Sch. For. 113:54—84. Bishop Museum Press, Honolulu. 1966. Wood anatomy of Composi 1995. Phylogeny, adaptive radiation, tae: A summary, with comments on factors and biogeography of Hawaiian Tetrarno controlling evolution. Aliso 6 (2): 1—23. lopiurn (Asteraceae, Astereae). Pages 195— 1975. Ecological strategies of xylem 220 in W. L. Wagner and V. Funk, eds. evolution. University of California Press, Hawaiian biogeography: Evolution on a Berkeley. hot spot archipelago. Smithsonian Institu 1982. The use of ethylenediamine in tion Press, Washington, D.C. softening hard plant structures for paraffin Lowrey, T. K., C. J. Quinn, R. K. Taylor, R. sectioning. Stain Technol. 57:311—317. Chan, R. T. Kimball, and J. C. De Nardi. 1994. Anatomy of tropical alpine 2001. Molecular and morphological re plants. Pages 111—128 in P. W. Rundel, assessment of relationships within the Vit A. P. Smith, and F. C. Meinzer, eds. tadinia group of Astereae (Asteraceae). Am. Tropical alpine environments: Plant form J. Bot. 88:1279—1289. and function. Cambridge University Press, Metcalfe, C. R., and L. Chalk. 1950. Anat Cambridge. omy of the dicotyledons. Clarendon Press, 2001. Comparative wood anatomy. Oxford. 2nd ed. Springer Verlag, Heidelberg. Okada, M., R. Whitkus, and T. K. Lowrey. Carlquist, S., and D. A. Hoekman. 1985. 1997. Genetics of adaptive radiation in Ecological wood anatomy of the woody Hawaiian and Cook Islands species of Tet southern California flora. IAWA (mt. As- ramolopium (Asteraceae: Astereae). I. Nu soc. Wood Anat.) Bull., n.s. 6:319—347. clear RFLP marker diversity. Am. J. Bot. Davis, S. J., S. Sperry, and U. G. Hacke. 84: 12 36—1246.
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