74,838 research outputs found
Metaphire dorsomultitheca Nguyen & Nguyen 2015
No full text<i>Metaphire dorsomultitheca</i> Nguyen & Nguyen, 2015 <p>(Figure 11, Table 3)</p> <p> <i>Metaphire dorsomultitheca</i> Nguyen <i>et al.</i> 2015: 465, fig. 2; Nguyen <i>et al.</i> 2016: 56, 2021c: 105.</p> <p> <i>Pheretima</i> sp. 15 <i>–</i> Nguyen 2013: 87, 2014: 112.</p> <p> <b>Type locality.</b> Vietnam (An Giang: Sam mountain) (Nguyen <i>et al.</i> 2015)</p> <p> <b>Type material.</b> Laboratory of Zoology, Department of Biology, Can Tho University (EW.025.h01, EW.025. p02), Vietnam.</p> <p> <b>Diagnosis.</b> Body cylindrical, small-medium size, length 76–111 mm, diameter 2.9–3.6 mm, segments 88–120. Prostomium epilobous. First dorsal pore at 12/13. Spermathecal pores numerous in dorsal intersegments 7/8/9, polythecate. Male pores located inside copulatory pouches in xviii. Genital markings invisible outside, but two pairs opened on the front and back walls of the copulatory pouches, respectively. Septum 10/11 present only ventrally. Intestinal caeca simple. Holandric, testis sacs separated. Accessory glands coelomic, strongly covered by muscularwalled bursae in 17/18 and 18/19.</p> <p> <b>Habitat.</b> The species was usually found in the depth of 0–5 cm in the soils under small trees and shrubs on mountain peaks (Nguyen <i>et al.</i> 2015).</p> <p> <b>Distribution.</b> Known only in Vietnam (An Giang: Sam, Cam, and Co To mountains) (Nguyen <i>et al.</i> 2015) (Fig. 3).</p> <p> <b>Remarks.</b> There are no significant differences between individuals except the number of spermathecae. The K2P intraspecific genetic distance was 0.7%±0.3%. The genetic distance between <i>M. dorsomultitheca</i> and other <i>Metaphire</i> species was from 14.9%±1.6% (with <i>M. bahli</i> (I)) to 21.8%±2.0 (with <i>M. grandiverticulata</i>) (Table 4).</p>Published as part of <i>Nguyen, Tung T., Lam, Dang H. & Nguyen, Anh D., 2023, A revision of the Metaphire peguana species-group (Oligochaeta: Megascolecidae) from Vietnam, pp. 113-135 in Zootaxa 5255 (1)</i> on pages 129-130, DOI: 10.11646/zootaxa.5255.1.15, <a href="http://zenodo.org/record/7744555">http://zenodo.org/record/7744555</a>
Metaphire kiengiangensis Nguyen & Trinh 2015
No full text<i>Metaphire kiengiangensis</i> Nguyen & Trinh, 2015 <p>(Figure 12, Table 3)</p> <p> <i>Metaphire kiengiangensis</i> Nguyen <i>et al.</i> 2015: 461, fig. 1; Nguyen <i>et al.</i> 2016: 60, 2017b: 898, 2021c: 105.</p> <p> <i>Pheretima</i> sp.9 – Nguyen 2013: 75, 2014: 111.</p> <p> <b>Type locality.</b> Vietnam (Kien Giang: Lai Son island) (Nguyen <i>et al.</i> 2015).</p> <p> <b>Type material.</b> Laboratory of Zoology, Department of Biology, Can Tho University (EW.019.h01, EW.019. p02, EW.019.p03, EW.019.p04), Vietnam.</p> <p> <b>Diagnosis.</b> Body cylindrical, large-medium size, length 176–280 mm, diameter 6.3–8.1 mm, segments 83–143. Prostomium epilobous. First dorsal pore at 12/13. Spermathecal pores numerous in ventrolateral intersegments 6/7/8/9, polythecate. Male pores located inside copulatory pouches in xviii. Two pairs of slit-shaped genital markings in 17/18 and 18/19. Male pores located inside copulatory pouches in xviii. Septum 10/11 present only ventrally. Intestinal caeca simple. Holandric, testis sacs separated. Accessory glands coelomic, strongly covered by muscularwalled bursae in 17/18 and 18/19.</p> <p> <b>Habitat.</b> The species was extremely abundant in a leaf-litter layer under perennial mango gardens of mountainous areas; They excreted their feces to create columns emerging from the soil surface (Nguyen <i>et al.</i> 2015).</p> <p> <b>Distribution.</b> Known only in Vietnam (Kien Giang: Hon Dat, Hon Me mountains, and Lai Son island) (Nguyen <i>et al.</i> 2015, 2017b) (Fig. 3).</p> <p> <b>Remarks.</b> There is a minor difference in spermathecae between specimens collected from the mainland and from islands (ovoid-shaped spermathecae with thin duct vs. cylindrical-shaped with stout duct) (Nguyen <i>et al.</i> 2015 <b>).</b></p> <p> The K2P intraspecific genetic distance was 0.7%±0.3%. The genetic distance between <i>M. kiengiangensis</i> and other <i>Metaphire</i> species was from 16.5%±1.8% (with <i>M. bahli</i> (II)) to 21.6%±2.0% (with <i>M. grandiverticulata</i>) (Table 4).</p>Published as part of <i>Nguyen, Tung T., Lam, Dang H. & Nguyen, Anh D., 2023, A revision of the Metaphire peguana species-group (Oligochaeta: Megascolecidae) from Vietnam, pp. 113-135 in Zootaxa 5255 (1)</i> on pages 130-131, DOI: 10.11646/zootaxa.5255.1.15, <a href="http://zenodo.org/record/7744555">http://zenodo.org/record/7744555</a>
Raphiocarpus taygiangensis C. H. Nguyen, K. S. Nguyen & Aver.
No full text<p> 8. <i>Raphiocarpus taygiangensis</i> C.H.Nguyen, K.S.Nguyen & Aver. in Nguyen <i>et al.</i> (2023: 21).</p> <p> <b>Type:</b> <i>—</i> VIETNAM. Quang Nam: Tay Giang District, A Xan Village, 1270 m, around point 15°48’57”N 107°19’47”E, 20 April 2022, <i>C.H.Nguyen</i> et al. CKH 2022042068 (holotype VNF, isotypes HN, LE!)</p> <p> <b>Distribution</b>:—The species is endemic to Vietnam, known on the basis of the only type collection in Quang Nam Province.</p> <p> <b>Ecology and phenology</b>:—It grows in evergreen broad-leaved submontane forests on granite and shale at elevations of about 1300 m a.s.l. Flowers in April–May.</p> <p> <b>Conservation status</b>:—Up to date, only one population of this species is currently known. Considering the small population size (less than 500 mature individuals growing on an area less than 5 km 2) and fragile habitat, the species conservation status was preliminarily assessed as Vulnerable (VU D2) according to the criteria of IUCN 2023 (Nguyen <i>et al.</i> 2023). No additional data become available since this assessment.</p>Published as part of <i>Nguyen, Cuong Huu, Wen, Fang, Pham, Toai Minh, Nguyen, Yen Thi, Bui, Thanh Minh, Bui, Doi The, Nguyen, Khang Sinh & Averyanov, Leonid V., 2023, The checklist of Raphiocarpus species (Gesneriaceae, Didymocarpinae) in the flora of Vietnam with the description of a new species, R. bicallosus, pp. 223-234 in Phytotaxa 616 (3)</i> on page 231, DOI: 10.11646/phytotaxa.616.3.2, <a href="http://zenodo.org/record/10084863">http://zenodo.org/record/10084863</a>
Metaphire nhuongi Nguyen 2016
No full text<i>Metaphire nhuongi</i> Nguyen, 2016 <p>(Figure 13, Table 3)</p> <p> <i>Metaphire nhuongi</i> Nguyen 2016: 442, fig. 2; Nguyen <i>et al.</i> 2021c: 105.</p> <p> <i>Pheretima</i> sp. 10 – Nguyen <i>et al.</i> 2012: 146.</p> <p> <i>Pheretima</i> sp. 14 – Nguyen 2013: 85, 2014: 112.</p> <p> <b>Type locality.</b> Vietnam (An Giang: Co To mountain) (Nguyen 2016)</p> <p> <b>Type material.</b> Laboratory of Zoology, Department of Biology, Can Tho University (EW.024.h01, EW.024. p02, EW.024.p03), Vietnam.</p> <p> <b>Diagnosis.</b> Body cylindrical, large-medium size, length 213–339 mm, diameter 8.9–9.5 mm, segments 120–148. Prostomium epilobous. First dorsal pore at 12/13. Four pairs of spermathecal pores in ventrolateral intersegments 5/6/7/8/9, bithecate. Two pairs of ellipsoid genital markings in intersegments 17/18 and 18/19, each with a small opening at the center. Male pores located inside copulatory pouches in xviii. Septum 10/11 present only ventrally. Intestinal caeca simple. Holandric, testis sacs separated. Accessory glands coelomic, strongly covered by muscularwalled bursae in 17/18 and 18/19.</p> <p> <b>Habitat.</b> The species found in the depth of 15–20 cm in soils of natural forests or in perennial mango gardens in a mountain foot. They excreted their feces to create columns emerging from the soil surface (Nguyen 2016).</p> <p> <b>Distribution.</b> Only recorded in Vietnam (An Giang: Co To, Phu Cuong, and Ta Pa mountains) (Fig. 3).</p> <p> <b>Remarks.</b> There were no significant morphological differences between individual found.</p> <p> The K2P intraspecific genetic distance was 1.3%±0.3%. The genetic distance between <i>M. nhuongi</i> and other <i>Metaphire</i> species was from 17.6%±1.8% (with <i>M. dorsomultitheca</i>) to 22.9%±2.1% (with <i>M. grandiverticulata</i>) (Table 4).</p> <p> <b> Key to species of <i>Metaphire peguana</i> species-group</b> </p> <p>1. – Bithecate, one pair of spermathecae per segment.......................................................... 2 – Polythecate, numerous spermathecae per segment......................................................... 6</p> <p> 2. – Four pairs of spermathecal pores in 5/6/7/8/9...................................................... <i>M. nhuongi</i> – Three pairs of spermathecal pores in 6/7/8/9............................................................... 3</p> <p> 3. – Genital markings paired in vi–ix............................................................. <i>M. doiphamon</i> – Genital markings absent in the spermathecal region......................................................... 4</p> <p> 4. <i>–</i> Spermathecal pores located ventrally. Ventral distance between spermathecal pores 0.15–0.29 body circumference. <i>M. bahli</i> – Spermathecal located more laterally. Ventral distance between spermathecal pores 0.33–0.50 body circumference....... 5</p> <p> 5. – The openings of genital markings small, slit-shaped or ellipsoid-shaped, in post-setal and pre-setal positions in xvii and xix, respectively....................................................................... <i>M. peguana laisonensis</i> – The openings of genital markings disc-shaped, in 17/18 and 18/19, expanding to reach two setal rings. <i>M. peguana peguana</i></p> <p> 6. – Spermathecal pores located in ventral intersegments 6/7/8/9. Genital markings paired in 17/18 and 18/ 19 <i>M.</i> kiengiangensis – Spermathecal pores located in dorsal intersegments 7/8/9. Genital markings opening on the walls of the copulatory pouches <i>M. dorsomultitheca</i></p>Published as part of <i>Nguyen, Tung T., Lam, Dang H. & Nguyen, Anh D., 2023, A revision of the Metaphire peguana species-group (Oligochaeta: Megascolecidae) from Vietnam, pp. 113-135 in Zootaxa 5255 (1)</i> on pages 131-132, DOI: 10.11646/zootaxa.5255.1.15, <a href="http://zenodo.org/record/7744555">http://zenodo.org/record/7744555</a>
Large thermoelectric effects in p-SiC/p-Si and n-SiC/p-Si heterojunctions
No full textThe thermoelectric effect is important for thermal sensing, energy harvesting and other applications. This paper investigates the Seebeck coefficient of silicon carbide (SiC) on silicon (Si) heterojunctions and discusses the mechanism underlying the observed effects. The measured Seebeck coefficients of p‐3C‐SiC/p‐Si and n‐3C‐SiC/p‐Si heterojunctions are much higher than other reported values for SiC materials. The maximum Seebeck coefficients of p‐3C‐SiC/p‐Si and n‐3C‐SiC/p‐Si obtained were 1720 µV/K at 383 K and –421 µV/K at 396 K, respectively. These values are almost three times higher than those of other p-SiC and n-SiC materials. The high Seebeck coefficient in SiC/Si heterojunctions is attributed to the unique structure of the heterojunctions, which enables thermally activated charge carriers to migrate from Si to SiC. The results suggest that these heterojunctions can be exploited to develop highly sensitive self-powered thermal sensors.Full Tex
Meristotheca lysonensis X.-V. Nguyen, X.-T. Nguyen, Kittle & McDermid 2022
No full textMeristotheca lysonensis X.-V. Nguyen, X.-T. Nguyen, Kittle & McDermid sp. nov. (Figs. 3–14) Holotype: VIETNAM. Quang Ngai: Ly Son Island; 15.3743 ° N; 109.1329 ° E, 15 February 2021, coll. X.- V. Nguyen & X.- T. Nguyen (ION - CS 210215 b, tetrasporophyte, Fig. 3). GenBank accession number for rbc L and COI-5 P: MZ 770759 and MZ 770756 Isotypes: VIETNAM. Ninh Thuan: Thai An; 11.5648 ° N; 109.1269 ° E, 20 February 2021, coll. X.- V. Nguyen & X. - T. Nguyen (ION - CS 210301 b, tetrasporophyte, Fig. 5). GenBank accession number for rbc L and COI-5 P: MZ770761 and MZ770758. VIETNAM. Quang Ngai: Ly Son Island; 15.3743 ° N; 109.1329 ° E, 02 April 2003, coll. H.- D. Nguyen & H.- T. Pham (ION -01011b, male plant, Fig. 6). GenBank accession number for rbc L and COI-5 P: MZ770760 and MZ770757 Habitat: Growing on dead corals in the mid-to lower intertidal zone where subjected to strong wave action. Etymology: The specific epithet refers to Ly Son Island, the type locality of the new species in Viet Nam. Description: Thalli prostrate or forming decumbent prostrate clumps; thallus attached to the substratum by many secondary holdfasts; thalli flattened, gelatinous in texture, deep rose-red to dark red, 10–20 cm tall with small papillae on the surface; divided into many broad segments in an irregularly dichotomous manner with rounded apices, becoming gradually narrower above and tapering below to a cuneate or sometimes cordate or heart-shaped base with a short slender stipe. Mature blades are 1–2 cm broad, margins entire at the beginning, later giving rise to irregularly branched obvious proliferations, broader or narrower intermixed; surface smooth, sometimes roughened by the presence of warty or short spinose processes (Figs 3, 4), pinkish or yellowish when dried (Figs 5, 6). Blades are 1.3–1.8 mm thick in the basal portions (Fig. 7), becoming progressively thinner upward, 320–450 µm thick below the apices (Fig. 8). Thalli are multiaxial and internally consist of a filamentous medulla. In traverse section, the outer cortex consists of 3– 4 layers of small, elongate cells, 12–20 µm in diameter, the inner cortex consists of 4–5 layers of bigger, ellipsoidal, or rounded cells, 40–140 µm in diameter. The medulla occupies about 20–30% of the blade thickness. Axial filaments run parallel to the longitudinal plane of the blade; adjacent axial filaments frequently linked by secondary pit-connections (Fig. 9). Crosswise filaments originate from inner cortical cells and traverse the blade to connect with inner cortical cells of the opposite side (Fig. 10). Tetrasporangia in scattered patches throughout the outer cortex on both dorsal and ventral sides of the entire blade except at tips and lowermost portions. Tetrasporangia are cut off from cortical cells located in the second layer of the outer cortex. In a few cases, tetrasporangial initials appear laterally, pit-connected to their parental cells (Fig. 11). Tetrasporangial initials are basally attached to their supporting parental cortical cells (Fig. 12, solid triangle), and basal pit-connections remain in mature tetrasporangia. Tetrasporangia zonately divided, 10–15 µm diameter and 40–45 µm long (Fig. 13). Spermatangia produced from the outermost cortical cells (Fig. 14). Female gametophytes were not observed. R emarks:A morphological comparison of M. lysonensis and other related species is given in Table 1. Meristotheca lysonensis sp. nov. differs from M. coacta based on M. lysonensis’ larger size and greater blade thickness, blades that do not bear proliferations along the margins, and usually smooth blade margins. M. lysonensis clade habit is compressed to flattened. Pit-connections between tetrasporangial initials and the supporting parental cells change from lateral (young tetrasporangium) to basal (divided tetrasporangium). Meristotheca lysonensis also differs from M. procumbens in terms of thallus size and thickness, and the smaller medulla thickness in cross-sections. Position of pit-connections between tetrasporangial initials and the parental cells differ: basal position in M. lysonensis sp. nov., unlike lateral position in M. procumbens. This new species also differs from M. papulosa because M. lysonensis has many secondary holdfasts compared to single or a few erect blades arising from a discoid holdfast in M. papulosa. There are no branchlets in M. lysonensis whereas M. papulosa shows branchlets.Published as part of Nguyen, Xuan-Vy, Nguyen, Xuan-Thuy & Kittle Iii, Ronald P., 2022, Meristotheca lysonensis sp. nov. (Solieriaceae, Rhodophyta), a new flattened species from Vietnamese waters, pp. 137-148 in Phytotaxa 574 (2) on pages 141-144, DOI: 10.11646/phytotaxa.574.2.2, http://zenodo.org/record/738082
Metaphire setosa Nguyen & Nguyen & Lam & Nguyen 2020, new species
No full text<i>Metaphire setosa</i>, new species <p>(Figs. 1, 6)</p> <p> <b>Material examined.</b> Holotype: 1 mature (CTU-EW.179. h01), bushes (11°34′2.2″N, 106°35′46.9″E), 84.9 m, Tan Khai commune, Hon Quan District, Binh Phuoc Province, 26 October 2017, coll. Luong Thi Huynh Tien. Paratypes: 6 matures (CTU-EW.179.p02), same data as holotype.</p> <p> <b>Diagnosis.</b> Small-sized worm, length 57.0– 73.5 mm, average diameter 1.6–3.2 mm. Prostomium not developed. First dorsal pore in 13/14. Three pairs of spermathecal pores in ventral 6/7/8/9. Setae unusual, arranged as two setal rings. Clitellum saddle-shaped, xiv–xvi. Male pores deeply located inside copulatory pouches in the setal ring xix. Five pairs of genital markings in xvi–xviii and xxi–xxii. Holandric. Intestinal caeca simple. Septum 8/9 thick, 9/10 absent.</p> <p> <b>Description.</b> Body cylindrical, small size, length 57.0– 73.5 mm, average diameter 1.6–3.2 mm, weight 0.5–1.6 g, segments 94–121. Body pale. Prostomium not developed. First dorsal pore in 13/14. Setae unusual, arranged as two setal rings, more obvious on ventral side; pre-clitellar setae stouter and denser than post-clitellar ones; setal number 119–135 in viii, 27–42 in xxx; setal distance aa=ab, zz=zy. Clitellum saddle-shaped, xiv–xvi without setae and dorsal pores. Female pore single, on round disc-shaped pad in midventral xiv.</p> <p>Three pairs of spermathecal pores in dorsal intersegments 6/7/8/9; two bean-shaped pads surrounding each spermathecal pore. No genital markings in the spermathecal region. Male pores located deeply inside copulatory pouches in the setal ring xix. Ventral distance between two openings of copulatory pouches about 0.35× body circumference. Genital markings paired ventrally in xvi–xviii and xx–xxi, one pair in each segment.</p> <p>Septa 6/7/8/9 thick, 9/10 absent, 10/11/12/13 thin. Oesophageal gizzard after viii. Intestinal origin at xv; caeca simple, paired in xxvii–xxv. Last hearts in xiii. Pharyngeal micronephridia developed in 5/6/7. Typhlosole simple, lamelliform. Lymph glands absent.</p> <p>Three pairs of spermathecae in vii–ix. Ampulla large, mushroom-shaped; ducts long, about ½ ampulla length. Diverticula longer than ampulla, folded and directly attached to the base of ampulla duct; seminal chamber long, bulletshaped. Spermathecal ducts without nephridia. No accessory glands.</p> <p>Holandric. Testis sacs in x and xi, connected. Seminal vesicles developed in xi and xii. Ovaries in 12/13. Ovisacs invisible. Prostate glands deeply lobuled, paired in xviii–xx; duct long, folded before entering copulatory pouch which is slightly elevated from body wall. Five pairs of accessory glands.</p> <p> <b>DNA barcode.</b> The amplification of the mitochondrial gene cytochrome oxidase subunit I (COI) failed.</p> <p> <b>Etymology.</b> The specific epithet “ <i>setosa</i> ” alludes to the unusual setal arrangement on this earthworm. It is used as an adjective.</p> <p> <b>Remarks.</b> The new species is very unique among known <i>Metaphire</i> species, with regard to its saddle-shaped clitellum and setal arrangement. There has been no report on <i>Metaphire</i> species with saddle-shaped clitellum. More interestingly, the setal pattern is completely different from all known pheretimoid species in Vietnam. The unusual setal pattern was only seen in the <i>Amynthas polyperichaeta</i> (Thai, 1984). The male region was finely coarse with dense setae which was known as the setal zone.</p>Published as part of <i>Nguyen, Tung T., Nguyen, Nam Q., Lam, Dang H. & Nguyen, Anh D., 2020, Six new species of the genus Metaphire Sims & Easton, 1972 (Annelida: Oligochaeta: Megascolecidae) from southeastern Vietnam, pp. 220-236 in Raffles Bulletin of Zoology 68</i> on pages 230-232, DOI: 10.26107/RBZ-2020-0019, <a href="http://zenodo.org/record/4577217">http://zenodo.org/record/4577217</a>
Berkowitz (Morris I.) Brandauer (Frederick P.) Reed (John H.) Folk Religion in an Urban Setting
No full textNguyen Van Phong Joseph. Berkowitz (Morris I.) Brandauer (Frederick P.) Reed (John H.) Folk Religion in an Urban Setting. In: Archives de sociologie des religions, n°30, 1970. p. 175
Berkowitz (Morris I.) Brandauer (Frederick P.) Reed (John H.) Folk Religion in an Urban Setting
No full textNguyen Van Phong Joseph. Berkowitz (Morris I.) Brandauer (Frederick P.) Reed (John H.) Folk Religion in an Urban Setting. In: Archives de sociologie des religions, n°30, 1970. p. 175
Parahellenia trongduyii Juan Chen, V. C. Nguyen, K. S. Nguyen & N. H. Xia 2023, sp. nov.
No full text<i>Parahellenia trongduyii</i> Juan Chen, V.C.Nguyen, K.S.Nguyen & N.H.Xia, <i>sp. nov.</i> <p> <b>Diagnosis</b>:—It is similar to <i>P. tonkinensis</i>, but differs in unbranched or barely branched (vs. densely branched) stems, narrowly triangularlanceolate (vs. broadly triangular) and glabrous (vs. densely pubescent) axillary buds, softly mucronate (vs. pungent, making a finger bleeding if touched) bract apex, yellow to whitish yellow labellum with longitudinal orange to red lines at center (vs. yellow labellum with longitudinal red lines at center), anther crest 9‒12 mm (vs. 3‒5 mm) long and slightly bilobed (vs. deeply bilobed) dorsal appendage of stigma.</p> <p> <b>Type</b>:— Collected from the material cultivated at V. C. Nguyen’s private garden on 25 August 2021, <i>V. C. Nguyen & V. K. Nguyen CD 01</i> (holotype HN; isotypes HN, IBSC). Originally collected by T. D. Nguyen in July 2019 from Vietnam, Dak Lak Province, Krong Bong District, Chu Yang Sin National Park, Yang Mao Commune, along banks of small streams at elevations of 700‒900 m a.s.l. (Figs. 1‒3).</p> <p> Terrestrial evergreen perennial <i>herb</i>. <i>Rhizome</i> plagiotropic, tuberous, 2‒4 cm in diam., brown externally, white internally, glabrous. <i>Leafy shoot</i> 75‒140(‒250) cm tall, up to 3 cm in diam. at base. <i>Stem</i> more or less straight, erect to suberect, unbranched or barely branched at higher nodes. <i>Axillary bud</i> 1 at each node, narrowly triangular-lanceolate, 12‒15 × 5‒6 mm, green with red tip, glabrous. <i>Bladeless sheaths</i> closed, reddish brown, membranous, caducous, glabrous. <i>Leaves</i> 10‒20, consistently clustered toward the shoot apex; <i>sheaths</i> closed, pale green when young, later becoming reddish brown, glabrous; <i>ligule</i> 1.8‒2.5 mm long, glabrous, upper margin minutely fimbriate; <i>petiole</i> 0.9‒2.2 cm long, 0.8‒1 cm in diam., adaxially grooved, yellowish green, reddish brown at base, glabrous; <i>blades</i> 20‒35 × 5‒8 cm, the lowest ones obovate to oblanceolate, the upper ones oblanceolate to elliptic, base narrowly attenuate, apex acuminate, adaxial surface deep green, abaxial surface pale green, glabrous on both sides, midvein slight sunken adaxially and conspicuously raised abaxially. <i>Inflorescence</i> arising directly from the rhizome, 20‒25 cm long (including peduncle and bracts only), lax; <i>peduncle</i> horizontal to ascending, terete, 4‒6 cm long, 1.4‒1.6 cm in diam., bearing 4‒6 sheaths, sheaths tubular, coriaceous, reddish brown, glabrous; <i>spike</i> 16‒20 × 6‒9 cm, narrowly ellipsoid or nearly cylindrical; <i>secondary peduncle</i> very short, glabrous; <i>bracts</i> 4‒5 × 2‒2.5 cm, the lowest bracts broadly elliptic, the upper ones elliptic, cucullate, apex softly mucronate (not pungent), coriaceous, pale brown to reddish brown, glabrous, each subtending 1 flower with 1 bracteole; <i>bracteoles</i> 2.5‒2.8 × 0.7‒0.9 cm, narrowly lanceolate, apex acuminate to spiny (but not pungent), coriaceous, pale brown to reddish brown, glabrous. <i>Flowers</i> 8.5‒10 cm long; <i>calyx</i> 3.2‒4 cm long, coriaceous, pale green when young, becoming reddish brown when old, glabrous, tube 2.5‒3.3 cm long, 7‒9 mm in diam., lobes 3, 0.7‒1 × 0.6‒0.7 cm, broadly ovate, slightly involute, apex softly mucronate, pale green with reddish brown apex when young, becoming reddish brown when old; <i>floral tube</i> (from apex of ovary to base of divergence of corolla lobes) 2.2‒2.5 cm long, 0.3‒0.5 cm in diam., fused with style in basal 1.6 cm, white, glabrous externally; <i>corolla lobes</i> 4.3‒5 × 1.9‒2.2 cm, obovate, white, glabrous; <i>staminal tube</i> (from the point of divergence of corolla lobes to base of divergence of labellum and stamen) 1.4‒1.7 cm long, yellow, with dense yellow hairs internally, pubescent externally; <i>labellum</i> 6.5‒7.5 × 5.5‒6.5 cm, flabellate after full expansion, yellow to whitish yellow with longitudinal orange to red lines at center, covered with glutinous papillae at center and base, margin rugose and pubescent; <i>stamen</i> 3.2‒3.6 cm long (when crest flattened), 0.6‒1 cm wide, petaloid, oblong, yellow, adaxially concave, glabrous, abaxially slightly convex and thickened, with sparse long glandular hair; <i>anther crest</i> 0.9‒1.2 cm long, 5.5‒6.2 mm wide, oblong, strongly recurved to revolute on abaxial side, yellow with longitudinal red lines at adaxial side, broadly acute to obtuse at apex, margin pubescent; <i>thecae</i> 0.9‒1 cm long, 1.8‒2.4 mm wide in the middle, slightly broadening towards ends. <i>Ovary</i> inferior, 1.1‒1.4 cm long, 5‒6 mm in diam., glabrous, trilocular with axile placentation and apically embedded beige-coloured gynopleural nectaries, each locule with numerous ovules; <i>style</i> 4.5‒4.8 cm long (free part), glabrous; <i>stigma</i> 1.7‒1.8 mm long, 2.8‒3.3 mm wide, semi-circular, flattened, 2-lobed, lobes overlapping, white, margin ciliate, dorsal appendage slightly bilobed, white. <i>Infructescence</i> of almost the same size as inflorescence, often continuously formed (with fruits at base when flowers still anthetic at apex), with persistent bracts and bracteoles. <i>Fruits</i> 1.8‒2.2 cm long, 1.1‒1.2 cm in diam., nearly ellipsoid, reddish brown, glabrous, with persistent calyces. <i>Seeds</i> 3‒4 × 2‒2.3 mm, irregularly barrel-shaped, black, aril basal and not enclosing the seed, white.</p> <p> <b>Phenology</b>:—Flowering from June to August; fruiting from July and likely continuing till October.</p> <p> <b>Etymology</b>:—The specific epithet is named after Mr. Nguyen Trong Duy, who collected the living material of the species in its type locality.</p> <p> <b>Suggested common names</b>:—Mía dò Trọng Duy (Vietnamese), <i>Øṃṁƛąae</i> (duō lè dì wō sŭn huā) (Chinese).</p> <p> <b>Distribution, habitat and conservation</b>:—This species is currently known from Chu Yang Sin National Park in Dak Lak Province and Thach Nham protected forest in Kon Tum Province in Vietnam. <i>Parahellenia trongduyii</i> grows in shady, moist places along small streams, in evergreen broad-leaved forests at elevations of 700–900 m a.s.l. We observed five clumps of the species in Chu Yang Sin National Park, a protected area where agricultural activities and exploitation of non-timber forest products are prohibited. Due to lack of information on the distribution (extent of occurrence (EOO) or areas of occupancy (AOO)) and population size of <i>P. trongduyii</i>, its conservation status is assessed here as Data Deficient (DD), following the IUCN Red List Categories and Criteria (IUCN 2012).</p> <p> <b>Notes</b>:—As elaborated in the diagnosis, <i>Parahellenia trongduyii</i> closely resembles <i>P. tonkinensis</i> but is readily distinguished from it in the field even by vegetative characters, e.g., barely branched leafy shoots and narrowly triangular-lanceolate glabrous buds.</p> <p> <i>Parahellenia trongduyii</i> is also similar to <i>P. candida</i>, but differs in reddish brown (vs. brown) and glabrous (vs. densely puberulent) bladeless sheaths, glabrous (vs. puberulous) abaxial side of leaf blade, softly (vs. sharply) mucronate bract apex and yellow (vs. white) flowers. A detailed comparison is provided in Table 1.</p> <p> <b>Additional specimen examined (paratype)</b>:— VIETNAM. Kon Tum Province: Kon Plong District, Thach Nham protected forest, 17 km N of Mang Den Town, near river, 14°45’26’’N 108°18’35’’E, 900 m, 8 June 2016, <i>M. S. Nuraliev 1673</i> (MW: MW0753815) (Fig. 4).</p>Published as part of <i>Chen, Juan, Nguyen, Van Canh, Nguyen, Van Khuong, Nguyen, Khang Sinh, Nuraliev, Maxim S. & Xia, Nianhe, 2023, Taxonomic studies on Parahellenia (Costaceae) in Vietnam: a new species, P. trongduyii, and a new combination, P. candida, pp. 72-80 in Phytotaxa 583 (1)</i> on pages 73-79, DOI: 10.11646/phytotaxa.583.1.7, <a href="http://zenodo.org/record/7609199">http://zenodo.org/record/7609199</a>
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