Research Article |
Corresponding author: Gang Yao ( gyao@scau.edu.cn ) Academic editor: Bo Li
© 2022 Langxing Yuan, Gan Tan, Wenhua Zhang, Bine Xue, Jiwen Deng, Lei Liu, Gang Yao.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Yuan L, Tan G, Zhang W, Xue B, Deng J, Liu L, Yao G (2022) Molecular and morphological evidence for a new species of Pogostemon (Lamiaceae) from Hainan Island, China. PhytoKeys 188: 177-191. https://doi.org/10.3897/phytokeys.188.76611
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Pogostemon hainanensis, a new species of Lamiaceae from Hainan Island, China, is described. The phylogenetic position of the new species within Pogostemon was investigated based on analyses of the nuclear ribosomal internal transcribed spacer (nrITS) and five plastid markers (viz. matK, psbA-trnH, rbcL, rsp16, trnL-F). The results show that P. hainanensis is supported to be a member of subgenus Pogostemon and is sister to P. parviflorus, a species widely distributed from Eastern Himalaya, through the Indo-China peninsula to China. Morphologically, the new species can be distinguished from all the other taxa of subgenus Pogostemon in having long petioles usually 4.5‒11.5 cm in length, and the calyx teeth 2/3 to subequal as long as the calyx tube. The new species differs from P. parviflorus further by its obviously double serrate leaf margin, spikes of inflorescence usually 2.5–8.0 cm long, calyx 4‒5 mm long and corolla 6–7 mm long.
China, Lamiaceae, Pogostemon, Pogostemoneae, taxonomy
Pogostemon Desf. is the largest genus in Pogostemoneae, Lamioideae, Lamiaceae (
Based on results from extensive field investigations conducted recently, multiple new species of Pogostemon were reported, such as P. nudus Bongcheewin & Pramali from Thailand (
In our taxonomic revision of Chinese Pogostemon (
Specimens of Pogostemon deposited in the herbaria BM, E, HITBC, IBK, IBSC, K, KUN, L, PE, US, NAS, TAI and NY were studied carefully in the present study. Herbarium abbreviations cited in the present study follow the Index Herbariorum (
To study the phylogenetic position of the new species within the genus Pogostemon, a phylogenetic study of the genus was performed, based on analyses of six DNA markers (nrITS, matK, psbA-trnH, rbcL, rps16, trnL-F), following
All the DNA sequences were aligned using MAFFT 7.221 (
The cpDNA dataset, nrITS dataset and combined dataset alignments contained 3872 bp, 707 bp and 4,579 bp, respectively. The topology of Pogostemon and its relatives derived from the nrITS dataset was largely consistent with that derived from the cpDNA dataset, except several nodes that were lowly supported (defined here as BS < 80% or PP < 0.80) (Suppl. material
Maximum likelihood (ML) tree of Pogostemon and its relatives inferred from the combined dataset (including nrITS, matK, psbA-trnH, rbcL, rps16, trnL-F). Bootstrap (BS) value in ML analysis and posterior probility (PP) in Bayesian inference (BI) is indicated on the left and right of slanting bar associated with phylogenetic node, respectively. Dashes denote that the phylogenetic node associated was not supported or the BS value is < 50% in ML anlaysis or PP < 0.50 in BI. The crown node of Pogostemon is show by the arrowhead.
Results from analyses of the combined dataset recovered a highly supported (defined here as BS ≥ 90% or PP ≥ 0.99) sister relationship between the two genera Anisomeles and Pogostemon (BS = 100%, PP = 1.00). Phylogenetic relationships of the genus Pogostemon obtained here are also consistent with those reported in
A detailed morphological comparison between the new species and other species of Pogostemon was conducted. A series of morphological characters of the new species, such as the obviously double serrated leaf margin (Figs
Only two species of subgenus Pogostemon [viz., P. cablin (Blanco) Benth. and P. esquirolii (H. Léveillé) C. Y. Wu & Y. C. Huang] were recorded previously in Hainan Island, China (
A detailed morphological comparison among the new species and its relatives or morphologically similar species also can be referred to Table
Morphological comparison among Pogostemon glaber Bentham, P. hainanensis L.X. Yuan & Gang Yao, P. parviflorus Bentham and P. septentrionalis Wu & Huang.
Morphology | P. glaber | P. hainanensis | P. parviflorus | P. septentrionalis |
---|---|---|---|---|
Leaf blade | Margin shallowly double serrate or double crenate | Margin obviously double serrate | Margin obscurely double crenate to double serrate | Margin double serrate |
Petiole | Usually 3–5 cm long | Usually 4.5‒11.5 cm long | Usually 1–4.5 cm long | Usually 0.5–5.5 cm long |
Inflorescence | Usually 3.0–15.0 cm long and 6‒10 mm wide | Usually 2.5–8.0 cm long and 9‒12 mm wide | Usually 0.7–3.5 cm long and 8–10 mm wide | Usually 3–13 cm long and 7–9 mm wide |
Calyx | 3‒4.5 mm long; the ratio of the length of calyx teeth and calyx tube is ca. 1/3 | 4‒5 mm long; the ratio of the length of calyx teeth and calyx tube is 2/3‒1.0 | 4‒4.2 mm long; the ratio of the length of calyx teeth and calyx tube is less than 1/2 | 3–4 mm long; the ratio of the length of calyx teeth and calyx tube is 1/3–1/2 |
Corolla | 3–5.5 mm long | 6–7 mm long | 4‒4.5 mm long | 4–4.5 mm long |
Morphologically, the new species has spikes of inflorescence with more than two later branches (Figs
The species is similar to Pogostemon parviflorus Benth. in general morphology, but differs from the latter by its leaves margin obviously double serrate, petioles usually 4.5‒11.5 cm long, spikes of inflorescence up to 8 cm long, calyx 4‒5 mm long, corolla 6–7 mm long, and the calyx teeth is 2/3 to subequal as long as the calyx tube.
China. Hainan province, Yinggeling Nature Reserve, Nanleshan, Fanyang, Wuzhishan, 18°54'38.25"N, 109°22'26.58"E, at an elevation of about 570 m, 6 February 2021, L.X. Yuan 20210206001 (holotype, IBSC; isotypes: IBSC, KUN).
Perennial herbs or shrubs, 0.8–2 m tall. Stem erect, 6–8 mm in diameter, 4-angular, slightly dilated at nodes, a few branched, strigose, or villous at the upper part. Leaves opposite; blade ovate, rarely ovate-lanceolate, (5.5–) 9–13.5 × (2.5) 6.5–10.5 cm, papery or membranous, strigose on both surfaces, base broadly cuneate, margin obviously double serrate, entire at base, apex acuminate; midvein elevated abaxially, lateral vein 3–4 (rarely 5) pairs on each side of the midvein, slightly elevated abaxially; petioles (1.5–) 4–11.5 cm long, ca. 1 mm in diameter, strigose. Spikes of inflorescence (1.0–) 2.5–8.0(–10.5) cm long, 9–12 mm in diameter, terminal and axillary, interrupted basally in long spikes, usually with more than two lateral branches; peduncle (1–) 2–4 cm long, densely villous; verticillasters many-flowered, flowers sessile. Bracts oblong, 5–13 × 2.5–5 mm, strigose, midvein elevated abaxially, lateral vein 1–2 pairs on each side of the midvein or sometimes obscure; bracteoles ovate-lanceolate to narrowly lanceolate, 2.5–5 × 0.7–1.8 mm, strigose. Calyx tubular-inflated, 4–5 mm long, 5-veined, strigose and sparsely golden glandular outside, sometimes sparsely strigillose inside at the upper part of tube; teeth 5, narrowly triangular, equal, 1.8–2 mm long, 0.6–0.8 mm wide at base, 2/3 to subequal as long as the calyx tube, subglabours or strigillose inside. Corolla white, 6–7 mm long, exserted evidently from calyx, 2-lipped, upper lip 3-lobed, lower lip entire. Stamens 4, erect, much exserted from corolla; filaments 7–7.5 mm long, all inserted at a height of ca. 2 mm in the tube, bearded at middle, bearded portion exserted; anther 1-locular, cell apex dehiscent. Style 7–7.5 mm long; stigma bifid, lobes subequal, 1.2–1.7 mm long. Disc ca. 0.6 mm long. Nutlets 4, ca. 0.7 × ca. 0.6 mm long, ellipsoid or slightly depressed globose, abaxially slightly flat, adaxially ribbed, black or dark brown.
Pogostemon hainanensis is named after its type locality, Hainan province, China.
Flowering from December to the next February and fruiting from January to April.
China. Hainan Province, Lingshui Hsien, 12 January 1934, near river, Z. Huang 36483 (IBSC-0585902!); Ledong Hsien, Jiaxi Nature Reserve, 18°52'35.85"N, 109°10'36.99"E, at an elevation of about 800 m, 7 February 2021, L.X. Yuan 20210207001 (IBSC); Baoting Hsien, near the Tiantan waterfall, 18°42'16.17"N, 109°41'50.55"E, at an elevation of about 560 m, 25 April 2021, L.X. Yuan 20210425001 (IBSC).
Hai Nan Ci Rui Cao (海南刺蕊草).
The authors are indebted to the curators of the herbaria BM, E, HITBC, IBK, IBSC, K, KUN, L, PE, US, NAS, TAI and NY for providing specimen images or hosting our visits. This study was financially supported by the Project of Species Resource Protection of Ministry of Agriculture and Rural Affairs (Grant No. 13210201) and the Forestry Scientific Technology Innovation Project of Guangdong Province (Grant No. 2020KJCX010).
Sequences and taxa information for all samples used in the present study (–, missing data; *, newly-generated sequences). Accession numbers are given for nrITS, matK, rbcL, rps16, trnH-psbA, trnL-F (c-f or c-d/e-f; the characters “c”, “d”, “e” and “f” indicate different primers used for PCR and sequencing of the marker trnL-F, referred from
Pogostemon amaranthoides Benth._28: –, KR608424, KR608489, KR608613, KR608548, KR608676; P. amaranthoides_42: KR608745, KR608425, KR608490, KR608614, KR608549, KR608677; P. aquaticus (C. H. Wright) Press_839: KR608767, KR608468, KR608527, KR608655, KR608592, KR608717; P. auricularius (L.) Hassk._8: KR608761, KR608451, KR608513, KR608638, KR608575, KR608700; P. barbatus Bhatti & Ingr._33: KR608762, KR608452, KR608514, KR608639, KR608576, KR608701; P. barbatus_118: KR608763, KR608453, KR608515, KR608640, KR608577, KR608702; P. benghalensis (Burm. f.) Kuntze: –, KR608444, –, HQ911592, KR608568, HQ911663/HQ911731; P. brachystachyus Benth._2: KR608775, KR608455, KR608517, KR608642, KR608579, KR608704; P. brachystachyus_12: KR608774, KR608454, KR608516, KR608641, KR608578, KR608703; P. cablin (Blanco) Benth._37: KR608757, KR608438, KR608503, KR608627, KR608562, KR608690; P. cablin _38: KR608752, KR608439, KR608504, KR608628, KR608563, KR608691; P. cablin_44: KR608753, KR608440, KR608505, KR608629, KR608564, KR608692; P. cablin_45: KR608754, KR608441, KR608506, KR608630, KR608565, KR608693; P. cablin_46: KR608755, KR608442, KR608507, KR608631, KR608566, KR608694; P. cablin_47: KR608756, KR608443, KR608508, KR608632, KR608567, KR608695; P. chinensis C. Y. Wu & Y. C.Huang_31: KR608743, KR608426, KR608491, KR608615, KR608550, KR608678; P. chinensis_117: KR608742, KR608449, KR608512, KR608637, KR608573, KR608699; P. crassicaulis (Benth.) Press_15: KR608770, KR608469, KR608528, KR608656, KR608593, KR608718; P. cruciatus (Benth.) Kuntze_25: KR608771, KR608466, KR608525, KR608653, KR608590, KR608715; P. dielsianus Dunn: MW194872, –, MW194874, MW194875, MW194873, MW194876; P. elsholtzioides Benth._63: –, KR608445, –, KR608633, KR608569, KR608720; P. formosanus Oliver_62: KR608744, KR608434, KR608499, KR608623, KR608558, KR608686; P. formosanus_90: KR608779, KR608435, KR608500, KR608624, KR608559, KR608687; P. fraternus Miq.: KR608781, KR608461, –, KR608648, KR608585, KR608710; P. gardner Hook. f._1: MF303612, MF303632, –, –, –, –; P. gardner_2: MF303603, MF303622, –, –, –, –; P. glaber Benth._3: KR608740, KR608431, KR608496, KR608620, KR608555, KR608683; P. glaber_13: KR608739, KR608429, KR608494, KR608618, KR608553, KR608681; P. glaber_214: KR608741, KR608430, KR608495, KR608619, KR608554, KR608682; P. hainanensis L.X. Yuan & Gang Yao_YG268: OL625022, OL616075, OL616077, OL616079, OL616081, OL616083; P. hainanensis_YG282: OL625023, OL616076, OL616078, OL616080, OL616082, OL616084; P. heyneanus Benth._1: KR608751, KR608427, KR608492, KR608616, KR608551, KR608679; P. heyneanus_2: –, HQ911401, –, FJ854069, –, FJ854297/FJ854184; P. hirsutus Benth.: –, HQ911397, –, FJ854070, –, FJ854298/FJ854185; P. hispidocalyx C. Y. Wu & Y. C. Huang_26: KR608780, KR608457, –, KR608644, KR608581, KR608706; P. linearis (Benth.) Kuntze_5: KR608764, KR608462, KR608521, KR608649, KR608586, KR608711; P. linearis_108: KR608765, KR608463, KR608522, KR608650, KR608587, KR608712; P. litigiosus Doan ex Suddee & A. J. Paton_53: KR608776, KR608458, KR608519, KR608645, KR608582, KR608707; P. litigiosus_54: KR608777, KR608459, KR608520, KR608646, KR608583, KR608708; P. macgregorii W. W. Sm._99: KR608778, –, –, –, –, –; P. paniculatus (Willd.) Benth._1: –, KR608450, –, –, KR608574, KR608721; P. paniculatus_2: –, HQ911399, –, FJ854071, –, FJ854299/FJ854186; P. parviflorus Benth._18: KR608749, KR608436, KR608501, KR608625, KR608560, KR608688; P. parviflorus_19: KR608750, KR608437, KR608502, KR608626, KR608561, KR608689; P. petelotii Doan ex G. Yao, Y. F. Deng & X. J. Ge_41: KR608772, KR608470, KR608529, KR608657, KR608594, KR608719; P. plectranthoides Desf._74: KR608760, KR608446, KR608509, KR608634, KR608570, KR608696; P. plectranthoides_109: KR608758, KR608447, KR608510, KR608635, KR608571, KR608697; P. plectranthoides_110: KR608759, KR608448, KR608511, KR608636, KR608572, KR608698; P. quadrifolius (Benth.) F. Muell._100: KR608773, KR608456, KR608518, KR608643, KR608580, KR608705; P. rogersii N E. Br.: KR608782, KR608460, –, KR608647, KR608584, KR608709; P. sampsonii (Hance) Press_11: KR608769, KR608465, KR608524, KR608652, KR608589, KR608714; P. septentrionalis C. Y. Wu & Y. C. Huang_39: KR608747, KR608432, KR608497, KR608621, KR608556, KR608684; P. septentrionalis_40: KR608748, KR608433, KR608498, KR608622, KR608557, KR608685; P. stellatus (Lour.) Kuntze_851: KR608768, KR608464, KR608523, KR608651, KR608588, KR608713; P. wightii Benth.: MF303601, MF303620, –, –, –, –; P. xanthiifolius C. Y. Wu & Y. C. Huang_27: KR608746, KR608428, KR608493, KR608617, KR608552, KR608680; P. yatabeanus (Makino) Press_48: KR608766, KR608467, KR608526, KR608654, KR608591, KR608716;
Outgroups: Achyrospermum africanum Hook. f. ex Baker: –, HQ911418, –, FJ853999, –, FJ854246/FJ854133; A. carvalhoi Gürke: –, HQ911412, –, FJ854001, –, FJ854248/FJ854135; A. cryptanthum Baker: –, HQ911415, –, FJ854002, –, FJ854249/FJ854136; A. wallichianum (Benth.) Benth. ex Hook. f.: –, –, –, HQ911594, –, HQ911666/HQ911734; Anisomeles heyneana Benth.: –, HQ911394, –, HQ911589, –, HQ911659/HQ911727; A. indica (L.) Kuntze_55: KR608726, KR608406, KR608471, KR608595, KR608530, KR608658; A. indica_115: –, KR608407, KR608472, KR608596, KR608531, KR608659; A. indica_116: KR608727, KR608408, KR608473, KR608597, KR608532, KR608660; A. indica_119: KR608728, KR608409, KR608474, KR608598, KR608533, KR608661; A. malabarica (L.) R. Br. ex Sims: –, HQ911396, –, FJ854013, –, FJ854260/FJ854147; Colebrookea oppositifolia Sm._21: KR608732, KR608414, KR608479, KR608603, KR608538, KR608666; C. oppositifolia_22: KR608733, KR608415, KR608480, KR608604, KR608539, KR608667; C. oppositifolia_23: KR608734, KR608416, KR608481, KR608605, KR608540, KR608668; Comanthosphace japonica (Miq.) S. Moore: –, HQ911407, –, FJ854029, –, FJ854272/FJ854159; C. stellipila S. Moore: –, HQ911408, –, FJ854030, –, FJ854273/FJ854160; Craniotome furcate (Link) Kuntze_1: KR608730, KR608412, KR608477, KR608601, KR608536, KR608664; C. furcate_6: KR608731, KR608413, KR608478, KR608602, KR608537, KR608665; Eurysolen gracilis Prain_16: KR608735, KR608417, KR608482, KR608606, KR608541, KR608669; E. gracilis_17: KR608736, KR608418, KR608483, KR608607, KR608542, KR608670; Leucosceptrum canum Sm._4: KR608738, KR608419, KR608484, KR608608, KR608543, KR608671; L. canum_20: KR608737, KR608420, KR608485, KR608609, KR608544, KR608672; Microtoena sp._9: KR608729, KR608410, KR608475, KR608599, KR608534, KR608662; M.> sp._10: –, KR608411, KR608476, KR608600, KR608535, KR608663; Rostrinucula dependens (Rehder) Kudô: –, HQ911405, –, FJ854074, –, FJ854302/FJ854189; R. sinensis (Hemsl.) C. Y. Wu: –, HQ911406, –, FJ854075, –, FJ854303/FJ854190; Colquhounia coccinea Wall._14: KR608722, KR608421, KR608486, KR608610, KR608545, KR608673; Gomphostemma sp._113: KR608723, KR608422, KR608487, KR608611, KR608546, KR608674; G. sp._114: KR608724, KR608423, KR608488, KR608612, KR608547, KR608675.
Figure S1
Data type: Phylogenetic tree
Explanation note: Supplementary Figure
Figure S2
Data type: Phylogenetic tree
Explanation note: Supplementary Figure