Plant Diversity xxx (2016) 1e10 Contents lists available at ScienceDirect Plant Diversity journal homepage: http://www.keaipublishing.com/en/journals/plant-diversity/ http://journal.kib.ac.cn Wuacanthus (Acanthaceae), a new Chinese endemic genus segregated from Justicia (Acanthaceae) * Yunfei Deng a, , Chunming Gao b, Nianhe Xia a, Hua Peng c a Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, People's Republic of China b Shandong Provincial Engineering and Technology Research Center for Wild Plant Resources Development and Application of Yellow River Delta, Facultyof Life Science, Binzhou University, Binzhou, 256603, Shandong, People's Republic of China c Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, People's Republic of China article info abstract Article history: A new genus, Wuacanthus Y.F. Deng, N.H. Xia & H. Peng (Acanthaceae), is described from the Hengduan Received 30 September 2016 Mountains, China. Wuacanthus is based on Wuacanthus microdontus (W.W.Sm.) Y.F. Deng, N.H. Xia & H. Received in revised form Peng, originally published in Justicia and then moved to Mananthes. The new genus is characterized by its 25 November 2016 shrub habit, strongly 2-lipped corolla, the 2-lobed upper lip, 3-lobed lower lip, 2 stamens, bithecous Accepted 25 November 2016 anthers, parallel thecae with two spurs at the base, 2 ovules in each locule, and the 4-seeded capsule. Available online xxx Phylogenetic analyses show that the new genus belongs to the Pseuderanthemum lineage in tribe Justi- cieae. Wuacanthus is closely related to Pseuderanthemum but differs from the latter by its shorter corolla Keywords: Acanthaceae tube and two minute spurs at the base of each anther-theca. W. microdontus is assessed with the status Jinshajiang Valley EN B2ab (iii) based on the IUCN Red List Categories and Criteria. Justicia Copyright © 2016 Kunming Institute of Botany, Chinese Academy of Sciences. Publishing services by Justicieae Elsevier B.V. on behalf of KeAi Communications Co., Ltd. This is an open access article under the CC BY- Pseuderanthemum lineage NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Wuacanthus 1. Introduction world (Graham, 1988; Mabberley, 2008; Hu et al., 2011). Two divergent trends were suggested by previous studies of the genus, Acanthaceae is a pantropical family consisting of about 230 resulting either in the recognition of a large number of small genera and 4000 species (Mabberley, 2008; Hu et al., 2011). Recent segregate genera or in the adoption of a very broad definition of phylogenetic studies of Acanthaceae have resulted in the recogni- Justicia. In the former, Bremekamp (1948) separated Justicia s.l. tion of four subfamilies, viz., Nelsonioideae, Thunbergiodeae, Avi- into several genera and his treatment was followed by many au- cennioideae and Acanthoideae. Acanthoideae differs from the other thors (e.g., Hu and Tsui, 2002). In contrast, Graham (1988) adopted three subfamilies in having reticulata and is further divided into a very broad definition of Justicia and divided the genus into 16 seven tribes, Acantheae, Ruellieae, Justicieae, Barlerieae, Neu- sections and 7 subsections. Graham's treatment was followed by rantheae, Andrographideae and Whitifieldieae (Reveal, 2012). Four the most recent works (Hu et al., 2011; Wood, 2014). The genus lineages were recognized by McDade et al. (2000) in Justicieae, viz., Justicia is characterized by several characters, including the 2- the Justicia lineage, Tetramerium lineage, Isoglossinae and Pseu- lipped corolla with the bilobed upper lip and trilobed lower lip, deranthemum lineage. two bithecous stamens, usually one thecae above the other, and Justicia L. is the largest genus in the family Acanthaceae and the lower one with a spur at the base (Graham, 1988, Hu et al., belongs to tribe Justicieae. It comprises approximately 600 species 2011). However, recent molecular evidence has indicated that and is distributed in the tropical and subtropical regions of the Justicia in the broad sense of Graham (1988) is paraphyletic (McDade et al., 2000; Gao, 2010). In China, 43 species were recognized in the recently published volume 19 of the Flora of China (Hu et al., 2011). Among these, * Corresponding author. Justicia microdonta W.W. Smith (1918) is quite different in that each E-mail address: [email protected] (Y. Deng). anther-theca has two spurs at the base, whereas the lower anther- Peer review under responsibility of Editorial Office of Plant Diversity. http://dx.doi.org/10.1016/j.pld.2016.11.010 2468-2659/Copyright © 2016 Kunming Institute of Botany, Chinese Academy of Sciences. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co., Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Please cite this article in press as: Deng, Y., et al., Wuacanthus (Acanthaceae), a new Chinese endemic genus segregated from Justicia (Acanthaceae), Plant Diversity (2016), http://dx.doi.org/10.1016/j.pld.2016.11.010 2 Y. Deng et al. / Plant Diversity xxx (2016) 1e10 theca has but one spur in other Chinese Justicia. The number of a total volume of 25 ml containing 1 ml DNA (100 ng/ml), 2.5 ml spurs of each theca seems to be an important character for dNTP (250 mm), 1 ml each primer (0.2 mm), 2.5 ml10Â buffer, delimitating generic boundary in the Acanthaceae. For example, 0.25 ml Taq polymerase (0.2U), and 17.5 ml ddH2O. The PCR cycling three genera in tribe Ruellieae were found to have two spurs at the conditions were exactly the same for all markers, [96 C 3 min, base of each theca. Diceratotheca is a genus described from Thailand (94 C 1 min, 52 Cor50C 1 min, 72 C 1 min) Â 32 cycles, 72 C in recent years (Wood et al., 2012). Stenothyrsus C.B. Clarke was 10 min]. The PCR products were purified on a column of sephadex described from the Malaysian state of Perak (Clarke, 1908). The and sequence reactions were read on an ABI 3730 or ABI 3730xl recent studies indicated that Chinese species of Echinacanthus genetic analyzer. differ from the type of Echinacanthus, Echinacanthus attenuatus Wall., in having two spurs at the base of each theca and represent a 2.5. Phylogenetic analyses new undescribed genus (Nees von Esenbeck, 1832; Lo and Fang, 1985; Hu and Tsui, 2002; Deng et al., 2010; Hu et al., 2011; Tripp Sequences for each region were edited by SeqMen (Lasergene 7), et al., 2013). Thus, it is also necessary to re-evaluate the phyloge- aligned with ClustalX (Thompson et al., 1997), and then adjusted by netic and taxonomic position of J. microdonta W. W. Smith. EditPlus manually. All sequences obtained in this study have been In the present study, we determine the phylogenetic position of deposited in Genbank (Table 1). Maximum parsimony (MP) and J. microdonta based on morphological data, especially the charac- Bayesian inference (BI) analyses were used on the individual and ters of anther, pollen and seed examined using scanning electron combined datasets. MP analyses were run with Paup* v.4.0b10 microscope (SEM), and molecular data. (Swofford, 2003). Heuristic search was performed with 1000 rep- licates of random addition sequence, tree bisection-reconnection 2. Material and methods (TBR) branch-swapping, retaining up to a single most parsimo- nious tree at each replicate. Strict consensus trees were constructed 2.1. Plant material from the most parsimonious trees. Bootstrap analyses (BP) were used to examine the support for individual clades (Felsenstein, Samples of pollen grains and seeds of J. microdonta were 1985). Bootstrap proportions >70% are considered well supported removed from Deng Yunfei et al. 25860 collected from Butuo Xian, (Hillis and Bull, 1993). Bayesian analyses were performed using Sichuan Province, China during our field investigations in October, MrBayes version 3.1.2 (Ronquist and Huelsenbeck, 2003). These 2014. Voucher specimens were deposited with the Herbarium of were produced using Modeltest 3.7 (Posada and Crandall, 1998)by the South China Botanical Garden, Chinese Academy of Sciences Hierarchical likelihood ratio test (hLRTs) and Akaike information (IBSC) and the Herbarium of the Kunming Institute of Botany, criterion (AIC) (Posada and Buckley, 2004). The Bayesian analyses Chinese Academy of Sciences (KUN). started from random trees sampling on tree every 100th generation In order to determine phylogenetic relationships in Justicieae with four incremental heated chains. The Markov chain Monte using molecular markers, we sampled 35 taxa in 18 genera. Leaf Carlo (MCMC) algorithm was run for 2000000e4000000 genera- material was dried in silica gel, and specimens from our field work tions for each dataset. The first 1000 trees corresponding to the were deposited at IBSC. To complete the dataset, additional DNA “burn-in” period were discarded, and the remaining trees were sequences of 39 species in 39 genera were obtained from GenBank used to construct a majority-rule consensus tree. We consider (Table 1). posterior probabilities (PP) > 0.95 to indicate significant probability for each clade. 2.2. Androecium observation The corolla samples were opened and observed under light 3. Results microscope and the number of stamens and staminodes were observed immediately. The anther samples were taken from the 3.1. Morphological characters flower and observed under SEM. J. microdonta is subshrub (Fig. 1: B) with the following charac- 2.3. Pollen and seed morphology observation teristics: leaves opposite, glabrous on both surfaces; inflorescence a terminal spike with 2e4 flowers per node (Fig. 1: C); bracts linear- Pollen grains were acetolysed following the modified method of lanceolate; bracteoles 2, similar to bracts; calyx 5-lobed almost to Erdtman (1969). The sampled pollen grains and seeds were base, lobes linear-lanceolate (Fig.