Journal of Plant Research (2019) 132:589–600
https://doi.org/10.1007/s10265-019-01129-3
REGULAR PAPER
First molecular phylogenetic insights into the evolution of Eriocaulon
(Eriocaulaceae, Poales)
Isabel Larridon1 · Norio Tanaka2 · Yuxi Liang1 · Sylvia M. Phillips1 · Anders S. Barfod3 · Seong‑Hyun Cho4 ·
Stephan W. Gale5 · Richard W. Jobson6 · Young‑Dong Kim4 · Jie Li7 · A. Muthama Muasya8 · John A. N. Parnell9 ·
Amornrat Prajaksood10 · Kohtaroh Shutoh11 · Phetlasy Souladeth12 · Shuichiro Tagane13 · Nobuyuki Tanaka2 ·
Okihito Yano14 · Attila Mesterházy15 · Mark F. Newman16 · Yu Ito17
Received: 4 March 2019 / Accepted: 29 July 2019 / Published online: 5 August 2019
© The Author(s) 2019
Abstract
Eriocaulon is a genus of c. 470 aquatic and wetland species of the monocot plant family Eriocaulaceae. It is widely distributed
in Africa, Asia and America, with centres of species richness in the tropics. Most species of Eriocaulon grow in wetlands
although some inhabit shallow rivers and streams with an apparent adaptive morphology of elongated submerged stems. In
a previous molecular phylogenetic hypothesis, Eriocaulon was recovered as sister of the African endemic genus Mesanthemum. Several regional infrageneric classifications have been proposed for Eriocaulon. This study aims to critically assess
the existing infrageneric classifications through phylogenetic reconstruction of infrageneric relationships, based on DNA
sequence data of four chloroplast markers and one nuclear marker. There is little congruence between our molecular results
and previous morphology-based infrageneric classifications. However, some similarities can be found, including Fyson’s sect.
Leucantherae and Zhang’s sect. Apoda. Further phylogenetic studies, particularly focusing on less well sampled regions such
as the Neotropics, will help provide a more global overview of the relationships in Eriocaulon and may enable suggesting
the first global infrageneric classification.
Keywords Aquatic plants · Eriocaulaceae · Evolution · Molecular phylogenetics · Monocots
Introduction
Eriocaulon L., commonly known as pipeworts, is a cosmopolitan genus of ephemeral and perennial aquatic and wetland plants of the Eriocaulaceae family (Poales). The genus
includes c. 470 species (WCSP 2019) and is most speciesrich in Asia (c. 220 species), the Americas (c. 122 species)
and Africa (c. 111 species), with its centres of diversity in
the tropics (Stützel 1998). Species of Eriocaulon primarily
grow in seasonal or permanent wetlands while some inhabit
shallow rivers and streams with an apparent adaptive morphology of elongated submerged stems. Two subfamilies
are recognised in Eriocaulaceae, i.e. Eriocauloideae with
Electronic supplementary material The online version of this
article (https://doi.org/10.1007/s10265-019-01129-3) contains
supplementary material, which is available to authorized users.
* Isabel Larridon
i.larridon@kew.org
diplostemonous flowers and glandular petals, and Paepalanthoideae with isostemonous flowers and eglandular petals
(Giulietti et al. 2012; Ruhland 1903). Together with the African genus Mesanthemum Körn., which was recently revised
by Liang et al. (2019), Eriocaulon is placed in subfamily
Eriocauloideae. Subfamily Paepalanthoideae is largely
restricted to the Americas.
Despite the ecological importance of Eriocaulon as a
species-rich genus of wetland plants, no attempts have been
made to reconstruct a molecular phylogeny for the genus.
Only a few Eriocaulon species have been included in the
sampling of family level studies (e.g. de Andrade et al.
2010; Giulietti et al. 2012). A molecular phylogenetic study
including a broad sampling covering much of the taxonomic,
morphological and geographic variation within the genus
is needed to assess whether the infrageneric taxa suggested
in the existing regional infrageneric classifications of Eriocaulon circumscribe monophyletic groups. It is a first step
in providing insights into the evolution of the genus and to
Extended author information available on the last page of the article
13
Vol.:(0123456789)
590
enable establishing a new infrageneric classification for the
whole genus in the future.
Several regional infrageneric classifications of the species of Eriocaulon have been proposed. Mueller (1859)
established two sections to accommodate the then known
Australian species of Eriocaulon, i.e. sect. Dimorphogyne
F. Muell. to accommodate E. heterogynum F. Muell. and
sect. Eriocaulon L. was established as autonym to place the
remaining six Australian species (Table S1).
Fyson (1919, 1921, 1922) established an infrageneric
classification for the Indian species of Eriocaulon, placing 51 species in eight named sections (Table S1). Later,
Ansari and Balakrishnan (1994, 2009) proposed an infrageneric classification of twelve numbered sections (I–XII)
for the Indian species of Eriocaulon (Table S1). There is
little overlap between these two classification systems for
India, although both Fyson (1919, 1921, 1922) and Ansari
and Balakrishnan (1994, 2009) place E. alpestre Hook.f. &
Thomson ex Körn. in a monotypic section (i.e. sect. ComatoSepalae Fyson and sect. I; Table S1). Also, species of sect.
Hirsutae Fyson appear to be mostly placed in sect. II and III
by Ansari and Balakrishnan (1994, 2009), while species of
sect. Leucantherae Fyson appear to be placed in sect. XII.
Ma (1991) classified the Chinese species of Eriocaulon
into subgen. Trimeranthus Nakai (27 species) and subgen. Eriocaulon sensu Nakai (monotypic: E. decemflorum
Maxim.). He further divided subgen. Trimeranthus into
three sections: sect. Macrocaulon Ruhl. (16 species); sect.
Leucocephala Nakai (three species); and sect. Spathopeplus
Nakai (eight species). Eriocaulon sect. Macrocaulon comprised ser. Tmetopsis Ruhl. (11 species) and ser. Leiantha
W.L.Ma (4 species), while sect. Spathopeplus consisted of
ser. Miqueliana Satake (2 species), ser. Robustiora W.L.Ma
(4 species), and ser. Manshanensia W.L.Ma (2 species) (Ma
1991) (Table S1). Later Ma (1997) added sect. Macrocaulon ser. Disepala Satake to retrieve E. merrillii Ruhl. and
E. sclerophyllum W.L.Ma from ser. Leiantha (Table S1).
The numbers of species classified were 32 in Ma (1997)
compared to Ma (1991) who accepted 28 species. Ma et al.
(2000) accepted 35 species in China and rejected all infrageneric classifications.
Zhang (1999) proposed an infrageneric classification
which placed 71 East Asian species in two subgenera and
10 sections (Table S1), recognising some of the sections
used by Fyson (1919, 1921, 1922) and Ma (1991, 1997)
together with some additional sections. There is little overlap between the classifications of Zhang (1999) and Ansari
and Balakrishnan (1994, 2009). However, E. hamiltonianum
Mart. and E. truncatum Buch.-Ham. ex Mart. are grouped in
sect. VII in Ansari and Balakrishnan (1994, 2009) and sect.
Disepala in Zhang (1999).
None of the published regional infrageneric classifications have yet been scrutinised using molecular phylogenetic
13
Journal of Plant Research (2019) 132:589–600
data. A molecular study by de Andrade et al. (2010) on Eriocaulaceae included just five species of Eriocaulon while the
study of Giulietti et al. (2012) included just four species. Of
the species sequenced in these studies, E. cinereum R.Br. is
the only one that has been included in the published infrageneric classifications. The objectives of this study are to:
(1) construct a molecular phylogeny of Eriocaulon, and (2)
critically assess the existing regional infrageneric classifications of Eriocaulon.
Materials and methods
Taxon sampling
Samples of Eriocaulon were collected in the field or
obtained from herbarium specimens (Table S2). The following regional treatments were used for specimen identifications because no comprehensive global revision has been
published: Cook (1996) and Ansari and Balakrishnan (2009)
for India; Prajaksood et al. (2017) for Thailand; Ma et al.
(2000) for China; Miyamoto (2015) for Japan; Bentham
(1878) and Leach (1992, 2000, 2017) for Australia; Cook
(2004) for southern Africa; Meikle (1968) for west tropical
Africa; Phillips (1998, 2010, 2011) for east and southern
tropical Africa. Cook (1996), Ma (1991, 1997) and Ma et al.
(2000) were referred to identify Indo-Burma specimens. The
recently described species E. petraeum S.M.Phillips & Burgt
and E. sulanum S.M.Phillips & Burgt (Phillips et al. 2012)
were sampled. Our sampling included 199 accessions (116
from Asia; 59 from Africa; 14 from America; ten from Australia) from 79 ingroup species representing 16.8% of species diversity of the genus Eriocaulon (Fig. 1; Table S2).
Xyris Gronov. of Xyridaceae and Mesanthemum, Syngonanthus Ruhl. and Tonina Aubl. of Eriocaulaceae, were chosen
as outgroup taxa following de Andrade et al. (2010).
DNA extraction, amplification and sequencing
Total genomic DNA was extracted from silica gel-dried leaf
tissues using the CTAB method described in Ito et al. (2010).
Four regions of chloroplast DNA (ptDNA), i.e. matK, rbcL,
rpoB and rpoC1 were PCR amplified with the following
primers: matK-390F (Cuénoud et al. 2002) and matK-1520R
(Whitten et al. 2000) for matK; rbcL-F1F (Wolf et al. 1994)
and rbcL-1379R (Little and Barrington 2003) for rbcL; “2f”
and “4r” for rpoB (Royal Botanic Gardens, Kew); and “1f”
and “3r” for rpoC1 (Royal Botanic Gardens, Kew). The PCR
amplification was conducted using TaKaRa Ex Taq polymerase (TaKaRa Bio, Shiga, Japan), and PCR cycling conditions
were 94 °C for 60 s; then 30 cycles of 94 °C for 45 s, 52 °C
for 30 s, 72 °C for 60 s; and finally, 72 °C for 5 min.
Journal of Plant Research (2019) 132:589–600
591
Fig. 1 Map of sampling localities of Eriocaulon species included in this study indicating the number of accessions sampled at each location
The PHYC gene (a distinct member of the phytochrome
gene family) was selected as a nuclear marker, based on its
phylogenetic utility as a single or low copy nuclear locus
(Mathews and Donoghue 1999; Samuel et al. 2005). Fragments of a part of exon 1 of PHYC were amplified by PCR
using Comm_PHYC_P1F (Hertweck et al. 2015) and the
newly designed AlisPHYC-1R (5′-GCATCCATTTCMACA
TCY TCCCA). The PCR cycling conditions were 94 °C
for 90 s; then 35 cycles of 94 °C for 45 s, 60 °C for 30 s,
72 °C for 90 s; and finally, 72 °C for 10 min. The fragments obtained were digested with ExoSAP-IT and directly
sequenced.
The PCR products were cleaned using ExoSAP-IT (GE
Healthcare, Piscataway, NJ, USA) purification, and then
amplified using ABI PRISM Big Dye Terminator v.3.1
(Applied Biosystems, Foster City, CA, USA) using the
same primers as those used for the PCR amplifications. DNA
sequencing was performed with an ABI PRISM 377 DNA
sequencer (Applied Biosystems). Automatic base-calling
was checked by eye in Genetyx-Win v.3 (Software Development Co., Tokyo, Japan). All sequences generated in the
present study have been submitted to the DNA Data Bank
of Japan (DDBJ), which is linked to GenBank, and their
accession numbers and voucher specimen information are
presented in Table S2.
Molecular phylogenetic analyses
Sequences were aligned using MAFFT v.7.058 (Katoh and
Standley 2013) and then inspected manually. Analyses
were independently performed for ptDNA (matK, rbcL,
rpoB, rpoC1) and PHYC datasets respectively to identify
possible incongruences between different genomic regions.
All 199 ingroup and the 13 outgroup accessions were represented in the ptDNA dataset, while 55 ingroup and five
outgroup accessions were represented in the PHYC dataset. The ptDNA dataset consisted of concatenated gene
alignments with 145 or 68% of accessions represented for
matK, 197 or 93% for rbcL, 122 or 58% for rpoB and 41
or 19% for rpoC1.
Phylogenies were reconstructed using maximum parsimony (MP), maximum likelihood (ML), and Bayesian inference (BI; Yang and Rannala 1997). In the MP analysis in
PAUP* v.4.0b10 (Swofford 2002), a heuristic search was
performed with 100 random addition replicates with treebisection-reconnection (TBR) branch swapping, with the
MulTrees option in effect. The MaxTrees option was set at
100,000. Bootstrap analyses (Felsenstein 1985) were performed using 1,000 replicates with TBR branch swapping
and simple addition sequences. The MaxTrees option was
set at 1,000 to avoid entrapment in local optima.
13
592
For the ML analysis, the RAxML BlackBox online server
(https://www.raxml-ng.vital-it.ch/) was used, which supports
GTR-based models of nucleotide substitution (Stamatakis
2006). The maximum likelihood search option was used to
find the best-scoring tree after bootstrapping. The gamma
model of rate heterogeneity was selected. Statistical support
for branches was calculated by rapid bootstrap analyses of
100 replicates (Stamatakis et al. 2008).
BI analyses were conducted with MrBayes v.3.2.2 (Ronquist and Huelsenbeck 2003; Ronquist et al. 2012) run on
the CIPRES portal (Miller et al. 2010) after the best models
had been determined in MrModeltest v.3.7 (Nylander 2002);
these models were GTR + I + G and GTR + G for ptDNA
and PHYC datasets, respectively. Analyses were run for
6,335,000 and 1,500,000 generations for ptDNA and PHYC
datasets, respectively, until the average standard deviation of
split frequencies dropped below 0.01, sampling every 1,000
generations and discarding the first 25% as burn-in. The convergence and effective sampling sizes (ESS) of all parameters were checked in Tracer v.1.6 (Rambaut et al. 2014). All
trees were visualized using FigTree v.1.3.1 (Rambaut 2009).
Support values are provided at the nodes [MP bootstrap support (BS), ML BS, BI posterior probability (PP)].
Molecular dating
A species tree was used to conduct a molecular dating analysis. A multispecies coalescent method (Heled and Drummond 2009) implemented in BEAST v.1.7.2 (Drummond
et al. 2006; Drummond and Rambaut 2007) was performed
to reconstruct a species tree. *BEAST was run using a multilocus dataset (ptDNA and PHYC) utilising all 212 ingroup
and outgroup samples assigned to the 84 operational taxonomic units (OTUs) that were retrieved as clades in the phylogenetic analyses above. For the purposes of this analysis,
species resolved as non-monophyletic or that contained multiple lineages are represented multiple times in the resulting
tree (i.e. E. cinereum R.Br., E. latifolium Sm., E. nepalense
J.D.Prescott ex Bong., E. plumale N.E.Br. and E. setaceum
L.).
A relaxed molecular clock as implemented in BEAST
v.2.4.4 (Drummond et al. 2006) was used and run on the
CIPRES portal (Miller et al. 2010). Uncorrelated lognormal distributed substitution rates for each branch were
used. The tree was rooted by constraining Eriocaulaceae.
Previous divergence time estimates between Eriocaulaceae
and Xyridaceae of 105 mya (million years ago) provided
by Janssen and Bremer (2004), Bouchenak-Khelladi et al.
(2014) and Hertweck et al. (2015) were used as a calibration point. These dates were set as a mean age with
stdev = 0.1 and a normal distribution. A Yule speciation
process was used as tree prior. The default settings of
13
Journal of Plant Research (2019) 132:589–600
BEAUti v.2.4.4 were used for the other parameters. Two
runs of ten million generations of the MCMC chains were
run, sampling every 1,000 generations. Convergence of the
stationary distribution was checked by visual inspection
of plotted posterior estimates using Tracer v.1.6 (Rambaut
et al. 2014). After discarding the first 1,000 trees as burnin, the samples were summarised in the maximum clade
credibility tree using TreeAnnotator v.1.6.1 (Drummond
and Rambaut 2007) with a posterior probability (PP) limit
of 0.5 and summarizing mean node heights. The results
were visualised using FigTree v.1.3.1 (Rambaut 2009).
Results
Molecular phylogeny
The ptDNA dataset for four genes included 4,445 aligned
characters, of which 889 were parsimony informative.
Analysis of this dataset yielded the imposed limit of
100,000 MP trees (tree length = 2,590 steps; consistency
index = 0.64; retention index = 0.88). The strict-consensus
MP tree, the RAxML tree, and the MrBayes BI 50% consensus tree showed no incongruent phylogenetic relationships; thus only the BI tree is presented here (Fig. 2a). Eriocaulon is broadly divided into two lineages: clade I and
clades II–XII. The clade II is resolved as sister to clades
III–XI. Clade III is resolved as sister to clades IV–XII. The
relationships among clades IV–XII are less well resolved,
except the weakly supported clades VIII–IX, yet each
clade is highly supported. Singleton X is differentiated
from clades XI–XII.
The PHYC dataset included 979 aligned characters, of
which 324 were parsimony informative. Analysis of this
dataset yielded the imposed limit of 100,000 MP trees (tree
length = 1,181 steps; consistency index = 0.53; retention
index = 0.81). The strict-consensus MP tree, the RAxML
tree and the MrBayes BI 50% consensus tree showed no
incongruent phylogenetic relationships; thus, only the BI
tree is presented here (Fig. 2b). The labelling of PHYC
tree follows the ptDNA tree. Eriocaulon is broadly divided
into two lineages: Clade I and clades/singletons II–III,
V–IX and XI–XII. Singleton III is resolved as sister to
clades/singletons II–XII. Singleton VI and clade VII are
retrieved as sister lineages, as are clades/singletons II, V,
VIII–IX and XI–XII. The relationships in the latter group
are less resolved. Clade II is strongly supported. Clade
XII plus Eriocaulon_schimperi_K3065 which belongs to
clade XI in the ptDNA analysis are strongly supported
as a natural group. Members of clade XI except Eriocaulon_schimperi_K3065 are retrieved as a clade.
Journal of Plant Research (2019) 132:589–600
593
Fig. 2 MrBayes trees of Eriocaulon based on: a concatenated
plastid DNA and b nuclear
PHYC datasets. Samples
collected in this study are
associated with the specified
vouchers. Branch lengths are
proportional to the number of
substitutions per site as measured by the scale bar. Values
above the branches represent
the maximum parsimony and
maximum likelihood bootstrap
support values (MP BS/ML
BS), and Bayesian posterior
probabilities (PP). BS < 70%
and PP < 0.9 are indicated by
hyphens while those of ≥ 90%
and ≥ 0.95 are shown as asterisks. Well-supported clades are
highlighted by gray rectangles
13
594
Fig. 2 (continued)
13
Journal of Plant Research (2019) 132:589–600
Journal of Plant Research (2019) 132:589–600
595
Fig. 2 (continued)
Molecular dating
The divergence time for each clade was estimated using the
calibration point between Eriocaulaceae and Xyridaceae
of 105 mya provided by Janssen and Bremer (2004),
Bouchenak-Khelladi et al. (2014) and Hertweck et al.
(2015). The most recent common ancestor (MRCA) of the
Eriocaulaceae family was estimated as early Paleogene
with the Eriocauloideae MRCA as mid-Paleogene. The
approximate divergence time for the MRCA of Eriocaulon was estimated as late Paleogene to early Neogene
(21.66 mya; 95% HDP = 15.88–28.36 mya) (Fig. 3). Most
of the species diversity of Eriocaulon appears to have
originated in the the last 10 mya (Fig. 3).
13
596
Journal of Plant Research (2019) 132:589–600
Fig. 3 BEAST maximum clade credibility tree for Eriocaulon obtained from plastid DNA (matK, rbcL, rpoB and rpoC1) and nuclear PHYC
sequence data. Clade depth and bars indicate mean nodal ages (mya) and 95% highest posterior density intervals
13
Journal of Plant Research (2019) 132:589–600
Discussion
Phylogeny and systematics of Eriocaulon
We reconstructed the phylogenetic history of Eriocaulon
using both ptDNA and PHYC datasets with the aim of
assessing the existing regional infrageneric classifications
(Table S1). Although our taxon sampling is not sufficiently
comprehensive to cover Mueller’s (1859) sectional classification for Australian species of Eriocaulon, selected
species listed in the infrageneric classifications proposed
by Fyson (1919, 1921, 1922), Ma (1991, 1997), Ansari
and Balakrishnan (1994, 2009) and Zhang (1999) were
sampled (Table S1, S2). Here, using the ptDNA tree
(Fig. 2a), we discuss whether and how the results support
these infrageneric classifications of as well as the previous
molecular phylogeny of de Andrade et al. (2010). There is
little congruence between our molecular results and previous morphology-based infrageneric classifications. However, some similarities can be found, as detailed below.
In de Andrade et al. (2010) ptDNA tree, Eriocaulon
cinereum was retrieved as sister to the other four species
including E. decangulare L. Our ptDNA tree recovered a
similar topology in which E. cinereum of clade II branches
off before E. decangulare of clade IV (Fig. 2a). Eriocaulon
cinereum belongs to sect. Leucantherae Fyson characterised by pale anthers and a smooth seed coat (Fyson 1919,
1921, 1922; Zhang 1999), and recognised by Ansari and
Balakrishnan (1994, 2009) as their sect. XII. This group
is represented by clade II of the ptDNA tree (Fig. 2a),
and hence upheld by both morphological and molecular
evidence.
Ma (1991, 1997) classified Chinese Eriocaulon into subgen. Trimeranthus of 27 species and subgen. Eriocaulon
accommodating E. decemflorum. Although neither subgen.
Trimeranthus nor most of its sections or series are supported in our results, it is noteworthy that E. decemflorum is
retrieved as a single species lineage (Fig. 2a clade X). It was
also placed as the only member of sect. Nasmythia by Zhang
(1999) based on its dimerous flowers and seed coat structure.
Ansari and Balakrishnan (1994, 2009) proposed an
infrageneric classification of the Indian species of Eriocaulon into twelve sections, primarily based on seed surface
structure. These are mostly not supported by our molecular
analysis. For instance, E. nepalense, E. parviflorum (Fyson)
R. Ansari & N.P. Balakr. and E. xeranthemum Mart. are
grouped in their sect. III, but are scattered in clades I, XI
and XII of the ptDNA tree (Fig. 2a). Similarly, E. truncatum
and E. hamiltonianum and are grouped in their sect. VII but
are here placed in clades XI and XII, respectively (Fig. 2a).
Zhang (1999) carried out a morphology-based cladistic
analysis of the 71 East Asian species studied. The resulting
597
cladograms divided the species into four groups. None of
these groups are supported in our ptDNA and PHYC trees
(Fig. 2). However, noteworthy in our results is the sister
relationship between clade I and the rest of Eriocaulon
(Fig. 2). Clade I accommodates relatively robust and large
species, i.e. E. australe R.Br., E. cuspidatum Dalzell and
E. sexangulare L. Zhang (1999) placed E. australe and E.
sexangulare in sect. Heterochiton Ruhland. Still, clades
II–XII contain morphologically similar species, such as
E. rufum Lecomte, E. schimperi Körn. ex Ruhland and E.
ubonense Lecomte.
Species distribution and taxonomy
Some species of Eriocaulon are known to have a wide
distribution in the Old World tropics, such as E. cinereum
and E. setaceum (Cook 1996, 2004). In the present study,
E. cinereum is divided into two lineages, one from Africa
and the other from Asia, although both fall within clade II
(Fig. 2a). Similarly, samples of E. setaceum from Africa
and Asia showed genetic variation (Fig. 2a clade XII). On
the other hand, no significant differentiations are observed
among samples of E. truncatum from Africa and Asia
(Fig. 2a clade XI). Species such as E. cinereum and E. truncatum are common in rice fields (Cook 1996), probably contributing to their widespread distribution around the world.
Clade I includes a subclade of 12 accessions of Eriocaulon australe and E. sexangulare. Prajaksood et al. (2012)
reduced E. australe to a variety of E. sexangulare (E. sexangulare var. australe (R.Br.) Praj. & J.Parn.). These taxa
differ in E. australe having hairy leaves, sheaths, involucral
bracts and receptable (Prajaksood et al. 2012; Zhang 1999).
From our results it appears that this character may not be
phylogenetically informative, and therefore, the varietal status of E. australe is supported.
Clade VII comprises Eriocaulon alpestre Hook.f. &
Thomson ex Körn., E. buergerianum Körn., E. sikokianum
Maxim., E. hondoense, E. miquelianum and E. taquetii with
limited genetic variation among samples (Fig. 2 clade VII).
This clade corresponds to subgen. Spathopeplus sect. Apoda
of Zhang (1999), a mainly Asian group of species with
female sepals connate into a spathe and seeds with T-shaped
projections. Our results reflect the taxonomic complexity of
this group in Japan, e.g. E. sikokianum Maxim. (accepted
name: E. miquelianum Körn.) and E. hondoense (accepted
name: E. taquetii Lecomte), while E. buergerianum_
TCMK_493_K needs critical re-identification because this
species is clearly diagnosed by floral morphology (Ma et al.
2000; Miyamoto 2015). Similarly, samples from Africa in
clade XII show no clear-cut phylogenetic difference based
on the markers used in this study: E. burttii S.M.Phillips, E.
crassiusculum Lye, E. deightonii Meikle, E. maronderanum
S.M. Phillips, E. mutatum N.E. Br, E. nigericum Meikle,
13
598
E. porembskii S.M. Phillips & Mesterházy, E. remotum
Lecomte and E. transvaalicum N.E. Br. However, these
species are all distinguishable morphologically by floral
structure and seed coat patterning (e.g. Phillips 1998, 2010,
2011). Further phylogenetic work is required to investigate
the morphology-based hypotheses for species delimitation
in Asian and African species of Eriocaulon.
Several of the 20 samples of Eriocaulon from Cambodia
are phylogenetically unique and distinguished from other
known species in both ptDNA and PHYC trees (Fig. 2). An
in-depth morphological analysis may reveal whether the collections belong to undescribed species.
Journal of Plant Research (2019) 132:589–600
human-nature mutualism’. Collection and identification of Thai specimens by A. Prajaksood were supported by Office of the Higher Education Commission, The Thailand Research Fund, Khon Kaen University
(MRG5480249) and Trinity College Dublin. We acknowledge curators
who allowed sampling of tissues from herbarium specimens (PRE). P.
Souladeth was supported by a Darwin Fellowship.
Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativeco
mmons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate
credit to the original author(s) and the source, provide a link to the
Creative Commons license, and indicate if changes were made.
Evolutionary history of Eriocaulon
References
Our results show that Eriocaulon originated in the late Paleogene to early Neogene (Fig. 3), and most species diversity
originated in the last 10 mya. With Eriocaulon occurring in
(permanent or ephemeral) wetlands across the tropics, the
increased speciation during this time may be due to drift
arising from fragmentation of suitable habitats associated
with aridification since mid-Miocene. During the same
period, Poales lineages like Cyperaceae and Poaceae that
evolved adaptation to aridification (e.g. C4 photosynthesis,
growing in non-wetland habitats) exhibited increased diversification (Bouchenak-Khelladi et al. 2014).
Ansari R, Balakrishnan NP (1994) Family Eriocaulaceae in India.
Bishen Singh Mahendra Pal Singh, Dehra Dun
Ansari R, Balakrishnan NP (2009) Family Eriocaulaceae in India, 2nd
edn. Bishen Singh Mahendra Pal Singh, Dehra Dun
Bentham G (1878) Eriocaulon. In: Bentham G, von Mueller F (eds)
Flora Australiensis 7. Cambridge University Press, Cambridge
Bouchenak-Khelladi Y, Muasya AM, Linder HP (2014) A revised evolutionary history of Poales: origins and diversification. Bot J Linn
Soc 175:4–16
Cook CD (1996) Aquatic and wetland plants of India: a reference book
and identification manual for the vascular plants found in permanent or seasonal fresh water in the subcontinent of India south of
the Himalayas, vol 198548214. Oxford University Press, Oxford
Cook CD (2004) Aquatic and wetland plants of southern Africa: an
identification manual for the stoneworts (Charophytina), liverworts (Marchantiopsida), mosses (Bryopsida), quillworts
(Lycopodiopsida), ferns (Polypodiopsida) and flowering plants
(Magnoliopsida) which grow in water and wetlands of Namibia,
Botswana, Swaziland, Lesotho and Republic of South Africa.
Backhuys, Leiden
Cuénoud P, Savolainen V, Chatrou LW, Powell M, Grayer RJ, Chase
MW (2002) Molecular phylogenetics of Caryophyllales based
on nuclear 18S rDNA and plastid rbcL, atpB, and matK DNA
sequences. Am J Bot 89:132–144
de Andrade MJ, Giulietti AM, Rapini A, de Queiroz LP, Conceição
AD, de Almeida PR, van den Berg C (2010) A comprehensive
phylogenetic analysis of Eriocaulaceae: evidence from nuclear
(ITS) and plastid (psbA-trnH and trnL-F) DNA sequences. Taxon
59:379–388
Drummond AJ, Rambaut A (2007) BEAST: Bayesian evolutionary
analysis by sampling trees. BMC Evol Biol 7:214
Drummond AJ, Ho SY, Phillips MJ, Rambaut A (2006) Relaxed phylogenetics and dating with confidence. PLoS Biol 4:e88
Felsenstein J (1985) Confidence limits on phylogenies: an approach
using the bootstrap. Evolution 39:783–791
Fyson PF (1919) The Indian species of Eriocaulon. J Indian Bot
1:51–55
Fyson PF (1921) The Indian species of Eriocaulon. J Indian Bot 2:133–
150 (192–207, 259–266, 307–320)
Fyson PF (1922) The Indian species of Eriocaulon. J Indian Bot
3(12–18):91–115
Giulietti AM, Andrade MJG, Scatena VL, Trovó M, Coan AI, Sano
PT, Santos FAR, Borges RLB, van den Berg C (2012) Molecular
phylogeny, morphology and their implications for the taxonomy
of Eriocaulaceae. Rodriguésia 63:1–19
Heled J, Drummond AJ (2009) Bayesian inference of species trees from
multilocus data. Mol Biol Evol 27:570–580
Future perspectives
For the time being, we refrain from suggesting a new infrageneric classification of this polymorphic and widespread
genus until the morphological characters used in previous
studies (e.g. seed surface structure, anther colour, floral
structure; Ansari and Balakrishnan 1994, 2009; Zhang 1999)
can be thoroughly investigated for their phylogenetic informativeness. Further phylogenetic studies, particularly focusing on less well sampled regions such as the Neotropics, will
help provide a more global overview of the relationships in
Eriocaulon and may enable suggesting the first global infrageneric classification. Further research may also aid towards
understanding closely related species groups in Africa and
Asia. This study should be seen as a step towards achieving
the aim of a natural classification.
Acknowledgements Research by I. Larridon is supported by the B.
A. Krukoff Fund for the Study of African Botany. The Royal Botanic
Garden Edinburgh (RBGE) is supported by the Scottish Government’s
Rural and Environmental Science and Analytical Services Division. A
grant for this work was provided to RWJ through the Australian Biological Resources Study (ABRS) National Taxonomy Research Grant
Programme (RG18-06). This study was supported by the Environment
Research and Technology Development Fund (S9) of the Ministry of
the Environment, Japan and by a JSPS grant from the Global Center
of Excellence Program ‘Asian Conservation Ecology as a basis of
13
Journal of Plant Research (2019) 132:589–600
Hertweck KL, Kinney MS, Stuart SA, Maurin O, Mathews S, Chase
MW, Gandolfo MA, Pires JC (2015) Phylogenetics, divergence
times and diversification from three genomic partitions in monocots. Bot J Linn Soc 178:375–393
Ito I, Ohi-Toma T, Murata J, Tanaka N (2010) Hybridization and polyploidy of an aquatic plant, Ruppia (Ruppiaceae), inferred from
plastid and nuclear DNA phylogenies. Am J Bot 97:1156–1167
Janssen T, Bremer K (2004) The age of major monocot groups inferred
from 800 + rbcL sequences. Bot J Linn Soc 146:385–398
Katoh K, Standley DM (2013) MAFFT multiple sequence alignment
software version 7: improvements in performance and usability.
Mol Biol Evol 30:772–780
Leach GJ (1992) Eriocaulaceae. In: Wheeler JR (ed) Flora of the Kimberley Region. Department of Conservation and Land Management, Como, pp 1026–1035
Leach GJ (2000) Notes and new species of Eriocaulon (Eriocaulaceae)
from Australia. Aust Syst Bot 13:755–772
Leach GJ (2017) A revision of Australian Eriocaulon (Eriocaulaceae).
Telopea 20:205–259
Liang Y, Phillips S, Cheek M, Larridon I (2019) Revision of African
genus Mesanthemum (Eriocaulaceae). Kew Bulletin (in press)
Little DP, Barrington DS (2003) Major evolutionary events in the origin and diversification of the fern genus Polystichum (Dryopteridaceae). Am J Bot 90:508–514
Ma W (1991) New materials of Eriocaulon L. from China. Acta Phytotax Sin 29:289–314
Ma W (1997) Eriocaulaceae. In: Kuo-fang W (ed) Flora Reipublicae
Popularis Sinicae 13(3). Science Press, Beijing, pp 20–63
Ma WL, Zhang Z, Stútzel T (2000) Eriocaulaceae. In: Flora of China,
vol 24, pp 7–17. http://flora.huh.harvard.edu/china/mss/volum
e24/ERIOCAULACEAE.published.pdf. Accessed 15 June 2019
Mathews S, Donoghue MJ (1999) The root of angiosperm phylogeny
inferred from duplicate phytochrome genes. Science 286:947–950
Meikle RD (1968) Notes on the Eriocaulaceae of West Tropical Africa.
Kew Bull 22:141–144
Miller MA, Pfeiffer W, Schwartz T (2010) Creating the CIPRES
Science Gateway for inference of large phylogenetic trees. In:
Proceedings of the gateway computing environments workshop
(GCE), 14 November 2010, New Orleans, LA, pp 1–8
Miyamoto F (2015) Eriocaulaceae. In: Ohashi H, Kadota Y, Murata
J, Yonekura K, Kihara H (eds) Wild flowers of Japan, vol 1.
Cycadaceae—Cyperaceae, Heibonsha, Tokyo, pp 280–286 (in
Japanese)
Mueller FJH (1859) Fragmenta Phytographiae Australiae 1:91–96
Nylander JA (2002) MrModeltest v1. 0b. Program distributed by the
author. Department of Systematic Zoology, Uppsala University,
Uppsala
Phillips SM (1998) Flora of Tropical East Africa, Eriocaulaceae edn.
Ed. Polhill. Balkema, Rotterdam
Phillips SM (2010) Flora Zambesiaca Vol.13(4): 33–86. Eriocaulaceae.
Royal Botanic Gardens, Kew
Phillips SM (2011) Flore du Cameroun 38. Eriocaulaceae. Ministry of
Scientific Research and Innovation, Yaoundé
Phillips SM, van der Burgt XM, Kanu KM (2012) Two new species
of Eriocaulon (Eriocaulaceae) from Sierra Leone. Kew Bull
67:273–280
599
Prajaksood A, Parnell JAN, Chantaranothai P (2012) New taxa and
new combinations of Eriocaulaceae from Thailand. Kew Bulletin
67:655–685
Prajaksood A, Chantaranothai P, Parnell JAN (2017) Eriocaulaceae. In:
Santisuk T, Balslev H (eds) Flora of Thailand 13(3):434–511 The
Forest Herbarium. National Park, Wildlife and Plant Conservation
Department, Bangkok
Rambaut A (2009) FigTree, version 1.3. 1. Computer program distributed by the author. http://www.treebioedacuk/software/figtr
ee. Accessed 4 Jan 2011
Rambaut A, Drummond AJ, Suchard M (2014) Tracer v1. 6. http://
beast.bio.ed.ac.uk. Accessed 8 Sept 2018
Ronquist F, Huelsenbeck JP (2003) MrBayes 3: Bayesian phylogenetic
inference under mixed models. Bioinformatics 19:1572–1574
Ronquist F, Teslenko M, Van Der Mark P, Ayres DL, Darling A, Höhna
S, Larget B, Liu L, Suchard MA, Huelsenbeck JP (2012) MrBayes
3.2: efficient Bayesian phylogenetic inference and model choice
across a large model space. Syst Biol 61:539–542
Ruhland W (1903) Eriocaulaceae. In: Engler A (ed) Das Pflanzenreich
IV, vol 30. Engelmann, Leipzig, pp 301–394
Samuel R, Kathriarachchi H, Hoffmann P, Barfuss MH, Wurdack
KJ, Davis CC, Chase MW (2005) Molecular phylogenetics of
Phyllanthaceae: evidence from plastid matK and nuclear PHYC
sequences. Am J Bot 92:132–141
Stamatakis A (2006) RAxML-VI-HPC: maximum likelihood-based
phylogenetic analyses with thousands of taxa and mixed models.
Bioinformatics 22:2688–2690
Stamatakis A, Hoover P, Rougemont J (2008) A rapid bootstrap algorithm for the RAxML web servers. Syst Biol 57:758–771
Stützel T (1998) Eriocaulaceae. In: Kubitzki K (ed) Families and genera of vascular plants 4. Springer, Berlin, pp 197–207
Swofford DL (2002) PAUP phylogenetic analysis using parsimony
(and other methods), Version 4.0 Beta 10. Sinauer Associates,
Sunderland
WCSP (2019) World checklist of selected plant families. Facilitated by
the Royal Botanic Gardens, Kew. http://wcsp.science.kew.org/.
Accessed 2 May 2019
Whitten WM, Williams NH, Chase MW (2000) Subtribal and generic
relationships of Maxillarieae (Orchidaceae) with emphasis
on Stanhopeinae: combined molecular evidence. Am J Bot
87:1842–1856
Wolf PG, Soltis PS, Soltis DE (1994) Phylogenetic relationships of
dennstaedtioid ferns: evidence from rbcL sequences. Mol Phyl
Evol 3:383–392
Yang Z, Rannala B (1997) Bayesian phylogenetic inference using DNA
sequences: a Markov Chain Monte Carlo method. Mol Biol Evol
14:717–724
Zhang Z (1999) Monographie der Gattung Eriocaulon in Ostasien.
Dissertationes Botanicae, Band 313
Publisher’s Note Springer Nature remains neutral with regard to
jurisdictional claims in published maps and institutional affiliations.
13
600
Journal of Plant Research (2019) 132:589–600
Affiliations
Isabel Larridon1 · Norio Tanaka2 · Yuxi Liang1 · Sylvia M. Phillips1 · Anders S. Barfod3 · Seong‑Hyun Cho4 ·
Stephan W. Gale5 · Richard W. Jobson6 · Young‑Dong Kim4 · Jie Li7 · A. Muthama Muasya8 · John A. N. Parnell9 ·
Amornrat Prajaksood10 · Kohtaroh Shutoh11 · Phetlasy Souladeth12 · Shuichiro Tagane13 · Nobuyuki Tanaka2 ·
Okihito Yano14 · Attila Mesterházy15 · Mark F. Newman16 · Yu Ito17
1
Royal Botanic Gardens, Kew, Richmond, Surrey TW9 3AE,
UK
10
Department of Biology, Faculty of Science, Khon Kaen
University, Khon Kaen 40002, Thailand
2
Department of Botany, National Museum of Nature
and Science, 4-1-1 Amakubo, Tsukuba, Ibaraki 305-0005,
Japan
11
The Hokkaido University Museum, Hokkaido University,
Kita 10, Nishi 8, Kita-ku, Sapporo, Hokkaido 060-0810,
Japan
3
Department of Bioscience, Aarhus University, Ny
Munkegade 114, 8000 Aarhus C, Denmark
12
National University of Laos, Dongdok Campus, Xaythany
District, Vientiane Capital, Lao PDR
4
Multidisciplinary Genome Institute, Hallym University,
Chuncheon 24252, Korea
13
The Kagoshima University Museum, Kagoshima University,
1-21-30 Korimoto, Kagoshima 890-0065, Japan
5
Kadoorie Farm and Botanic Garden, Lam Kam Road, Tai Po,
New Territories, Hong Kong, SAR, China
14
6
National Herbarium of New South Wales, Royal Botanic
Gardens and Domain Trust, Mrs Macquaries Road, Sydney,
NSW 2000, Australia
Department of Biosphere-Geosphere Science, Faculty
of Biosphere-Geosphere Science, Okayama University
of Science, Ridai-cho 1-1, Kita-ku, Okayama,
Okayama 700-0005, Japan
15
Directory of Hortobágy National Park, Sumen utca 2,
Debrecen 4024, Hungary
16
Royal Botanic Garden Edinburgh, 20A Inverleith Row,
Edinburgh, Scotland EH3 5LR, UK
17
Faculty of Pharmaceutical Sciences, Setsunan University,
Osaka, Japan
7
Xishuangbanna Tropical Botanical Garden, Plant
Phylogenetics and Conservation Group, Chinese Academy
of Sciences, Kunming 650223, China
8
Department of Biological Sciences, University of Cape
Town, Bolus Herbarium, Private Bag X3, Rondebosch 7701,
South Africa
9
Herbarium, Botany Department, Trinity College Dublin,
Dublin 2, Ireland
13