[Botany • 2026] Ophiorrhiza xinchengensis (Rubiaceae) • A New Species from Guangxi, China

Ophiorrhiza xinchengensis Y.Nong & G.Y.Wei, 

in Wei, J.-Y. Li, Chen, Y. Nong, Hu, Y.-J. Li, Ji, Xu et Y.-K. Nong. 2026. 

忻城螺序草  |  DOI: doi.org/10.3897/phytokeys.278.194094

Abstract

Ophiorrhiza xinchengensis (Rubiaceae), a new species from the middle part of Guangxi, China, is described and illustrated on the basis of morphological evidence. This new species resembles Ophiorrhiza longanensis in its densely pubescent stems, linear stipules, terminal or upper axillary inflorescences, but it can be distinguished by its elliptic or oblanceolate leaf blade, base attenuate (vs. oval, ovate to broadly ovate, base cuneate), its 2–3 mm long stipules (vs. 3.8–6.5 mm long), its 3–5 mm long bracteoles (vs. 6–10 mm long) its 10–12 mm long corolla tubes (vs. 2–3 mm long) and its filaments adnate at the middle of corolla tube, styles 12–15 mm long (vs. adnate to the base of corolla tube and styles ca. 3 mm long). The new species is currently known from a single population with approximately 60–100 mature individuals. Following IUCN Criteria, it is provisionally assessed as Critically Endangered. Photographs, an illustration and a distribution map are also provided.

Key words: Karst, new species, Ophiorrhiza, Spiradiclis, taxonomy

Ophiorrhiza xinchengensis Y.Nong & G.Y.Wei.
A. Habitat; B, C. Flowering plant; D. Stem, showing the linear stipules; E. Inflorescences; F. Fruiting plant; G. Dissected brevistylous flower; H. Dissected longistylous flower; I. Hypanthium, calyx, style and stigma; J. Ovary and calyx; K. Stigma; L. Bracts; M, N. Leaf (abaxially and adaxially); O. Capsule; P. Seeds.

Ophiorrhiza xinchengensis Y.Nong & G.Y.Wei, sp. nov.

 

Chinese name. “xīn chéng luó xù cǎo” (忻城螺序草).

Diagnosis. Ophiorrhiza xinchengensis is resembles Ophiorrhiza longanensis (R.J.Wang) Razafim. & Rydin in its densely pubescent stems, linear stipules, terminal or upper axillary inflorescences, but it can be distinguished by its elliptic or oblanceolate leaf blade, base attenuate (vs. oval, ovate to broadly ovate, base cuneate), its 2–3 mm long stipules (vs. 3.8–6.5 mm long), its 3–5 mm long bracteoles (vs. 6–10 mm long), its 10–12 mm long corolla tubes (vs. 2–3 mm long) and its filaments adnate at the middle of corolla tube, styles 12–15 mm long (vs. adnate to the base of corolla tube, styles ca. 3 mm long).

Etymology. The specific epithet “xinchengensis” refers to the type location of the new species.

 Gui-Yuan Wei, Jin-Yue Li, Rong Chen, You Nong, Qi-Min Hu, Ying-Jing Li, Xing-Yun Ji, Chuan-Gui Xu, Yun-Kai Nong. 2026. Ophiorrhiza xinchengensis (Rubiaceae), A New Species from Guangxi, China. PhytoKeys. 278: 1-14.  DOI: doi.org/10.3897/phytokeys.278.194094 [24-07-2026]

[Botany • 2026] Ophiorrhiza saxatilis (Rubiaceae) • A New Species from Guizhou, China

Ophiorrhiza saxatilis M.T.An & G.L.Li,

in Li, An, Wu, Yu, Qiu, Liu et Tan, 2026. 

 岩生蛇根草  ||  DOI: doi.org/10.3897/phytokeys.278.197480

Abstract

Ophiorrhiza saxatilis M.T.An & G.L.Li, sp. nov., a new species of the genus Ophiorrhiza (Rubiaceae) discovered in the karst regions of Guizhou, China, and provides its taxonomic basis from a morphological perspective. The new species is morphologically similar to Ophiorrhiza lignosa, but differs from the latter by having an inflorescence in that its young branches are uniformly pubescent (vs. bifariously pubescent in O. lignosa); the abaxial leaf surface is pubescent (vs. puberulent only along the midrib and secondary veins in O. lignosa); the bracteoles are 5–6 mm long (vs. 1.5–3 mm long in O. lignosa); the petioles are 2–5.8 mm long (vs. 6–20 mm long in O. lignosa); the stamens are inserted at the base of the corolla tube (vs. inserted near the middle of the corolla tube in O. lignosa); the flowers are distylous (vs. monomorphic with pin flowers in O. lignosa), and the styles of long-styled flowers are 6–8 mm long (vs. 10–11 mm long in O. lignosa). These stable and significant morphological differences, combined with a comprehensive and detailed morphological description of the new species and a comparison of diagnostic characters with similar species, firmly support the recognition of Ophiorrhiza saxatilis as a distinct new species.

Key words: Karst, Morphology, New Taxon, Ophiorrhiza, Rubiaceae

Ophiorrhiza saxatilis.
A, B. Habitat; C. Plant; D. Flowering branch; E. Dissected flowers: long-styled flower (above) and short-styled flower (below); F. Style of long-styled flower; G. Style of short-styled flower; H. Longitudinally dissected short-styled flower; I. Longitudinally dissected long-styled flower; J. Fruit; K. Infructescence; L. Adaxial leaf surface; M. Abaxial leaf surface; N. Branchlets.

Ophiorrhiza saxatilis M.T.An & G.L.Li, sp. nov.

Diagnosis. Ophiorrhiza saxatilis is morphologically similar to O. lignosa Merr., but can be distinguished by several key characteristics (Table 2): uniformly pubescent young branches (vs. bifariously pubescent); white corolla lobes with ridges (vs. purple, without ridges); stamens inserted at the base of the corolla tube (vs. inserted near the middle of the corolla tube); flowers distylous (vs. monomorphic, with pin flowers); long-styled flowers 6–8 mm long (vs. 10–11 mm long); purple midrib on the abaxial leaf surface (vs. green); abaxial leaf surface pubescent (vs. puberulent only on the midrib and secondary veins); bracteoles 5–6 mm long (vs. 1.5–3 mm long); and petioles 2–5.8 mm long (vs. 6–20 mm long).

Etymology. The specific epithet is derived from the habitat of the new species, which occurs in a typical karst limestone environment. It mainly grows in harsh habitats such as rock crevices and stony slopes.

Local name. Simplified Chinese: 岩生蛇根草;
Chinese Pinyin: yán shēng shé gēn cǎo.

 Guang-Lin Li, Ming-Tai An, Xu Wu, Jiang-Hong Yu, Jian Qiu, Shao-Fei Liu and Cheng-jiang Tan. 2026. Ophiorrhiza saxatilis (Rubiaceae), A New Species from Guizhou, China. PhytoKeys. 278: 27-37.  DOI: doi.org/10.3897/phytokeys.278.197480 [24-07-2026]

[Botany • 2026] Microlicia almedae (Melastomataceae) • A New Species from the Chapada Diamantina, Bahia, Brazil

Microlicia almedae  R.B.Pacifico & Kriebel,

in Pacifico et Kriebel, 2026. 

DOI: doi.org/10.3897/phytokeys.276.193021

Abstract

A new species, Microlicia almedae, is described and illustrated from the species-rich campo rupestre vegetation of Chapada Diamantina, Bahia, Brazil. The taxonomic novelty is morphologically related to M. giuliettiana and M. pulchra, which are also restricted to Chapada Diamantina. Microlicia almedae differs from the latter two species in leaf shape and size, hypanthium indumentum, calyx lobe shape and size, and petal size. In addition, M. almedae differs from M. giuliettiana by its uniformly magenta petals and from M. pulchra by its capsules with deciduous columellae. Variation in leaf shape among M. almedae, M. pulchra, and M. giuliettiana was quantified using elliptic Fourier analysis, which revealed near-complete separation among the three species.

Key words: Campo rupestre, Lavoisiereae, Pico da Lapa Grande, Serra do Barbado, taxonomy

Microlicia almedae.
 A. Habit; B. Flower; C. Landscape with campo rupestre vegetation at Serra do Barbado, the type locality of M. almedae.

Voucher: L. Daneu et al. 796 (JABU). 

Photos: by L. Daneu (A, B); by E.A. Ramos (C).

Microlicia almedae.
A. Habit; B. Close-up of a branch; C. Leaf adaxial surface; D. Leaf abaxial surface; E. Detail of glandular-punctate adaxial surface; F. Detail of glandular-punctate indumentum on abaxial surface; G. Flower in lateral view; H. Flowering hypanthium and calyx lobes; I. Detail of the indumentum on the hypanthium; J. Petal in adaxial view; K. Antepetalous (left) and antesepalous (right) stamens; L. Gynoecium; M. Apex of style and stigma; N. Ovary in cross-section; O. Capsule enveloped by the hypanthium and calyx lobes; P. Seed in lateral view.

Illustration by Klei Sousa based on L. Daneu et al. 796 (JABU).

  

Microlicia almedae R.B.Pacifico & Kriebel, sp. nov.

Ricardo Pacifico and Ricardo Kriebel. 2026. Microlicia almedae (Melastomataceae), A New Species from the Chapada Diamantina, Bahia, Brazil. PhytoKeys. 276: 183-195. DOI: doi.org/10.3897/phytokeys.276.193021 [12 Jun 2026]

 

[Botany • 2026] Ceropegia gengmaensis (Apocynaceae: Ceropegieae) • A New Species from Yunnan, China

 

Ceropegia gengmaensis  P.R.Luo, A.Liu & H.Sun,

in Luo, Liu, Tong, Zhang, Wang, Deng, Goyder et Sun, 2026. 

耿马吊灯花  ||  DOI: doi.org/10.3897/phytokeys.276.197333

Abstract

Ceropegia gengmaensis P.R.Luo, A.Liu & H.Sun, a new species from Gengma County, Yunnan, Southwest China, is described. Both morphological characteristics and chloroplast phylogenetic analysis strongly support its placement within C. sect. Chionopegia H.Huber. Molecular data further reveal that C. gengmaensis is closely related to C. salicifolia, C. mairei, and C. dolichophylla, yet it can be distinguished from them readily by its stem indumentum, leaf shape, and floral morphology, particularly the shape of the corolla tube, and features of the lobes. A detailed line drawing of this new species is also provided.

Key words: Ceropegieae, Chloroplast, Karst Landform, Morphology, Southwest China

Ceropegia gengmaensis. 
 A, B. Plant showing the rootstock; C, D. Upper and lower sides of leaf; E. Inflorescence with bases of adjoining leaves; F. Corolla tube dissected longitudinally; G. Side view of gynostegium (with sepals and pedicel shown); H. Top view of gynostegium with sepals shown; I. Ovary; J Pollinarium.

 Scale bars: 15 cm (A, B); 5 cm (C, D); 4 cm (E, F); 1 cm (G); 0.8 cm (H); 0.3 cm (I); 0.5 mm (J).

Morphological features of Ceropegia gengmaensis based on living plants collected from the type locality.
 A. Plant showing the rootstock; B, C. Leaf: B, abaxial surface and C, adaxial surface; D. Stem; E, F. Corolla: E, corolla from the outside with its base cut off and F, corolla with the tube dissected longitudinally; G. Small peduncle, part of the pedicel and petiole; H. White hairs on the inside of the base of the tube; I. Side view of gynostegium; J. Gynostegium from above; K. Pollinarium.

Scale bars: 15 cm (A); 5 cm (B, C); 4 cm (D, E, F); 1 cm (G, H, I); 0.8 cm (J); 0.5 mm (K).

Ceropegia gengmaensis P.R.Luo, A.Liu & H.Sun, sp. nov.

 

Diagnosis. Ceropegia gengmaensis shows affinities with C. salicifolia and C. dolichophylla, both of C. sect. Chionopegia . It differs from C. salicifolia by its erect to sprawling habit (vs. twining), elliptic leaves 2.0–5.5 cm (vs. lanceolate, 6–15 cm), densely pubescent stems bearing usually solitary flowers (vs. glabrous stems with sessile cymose many-flowered inflorescences), and narrower corolla lobes with only slight expansion above the throat (vs. lobes longer and wider, upper portion markedly expanded). From C. mairei it differs by the much less pronounced basal inflation of the tube (vs. a strongly inflated tube) and ... 

Etymology. Ceropegia gengmaensis is named after its type locality, Gengma County, Southwest Yunnan.

Vernacular name. the Chinese name is given as “耿马吊灯花” (gěng mă diào dēng huā) named after the type locality, Gengma County, Southwest Yunnan.

Peng-Rui Luo, Ang Liu, Rui Tong, Xin-Jian Zhang, Zi-Yi Wang, Tao Deng, David J. Goyder and Hang Sun. 2026. Ceropegia gengmaensis (Apocynaceae), A New Species from Yunnan, China. PhytoKeys. 276: 217-228. DOI: doi.org/10.3897/phytokeys.276.197333 [15 Jun 2026]

[Botany • 2026] Argostemma baotingense (Rubiaceae) • A New Species from Hainan Island, South China

 

Argostemma baotingense S.P.Dong & H.B.Yang, 

 in Dong, Yuan, Wang et Yang, 2026. 

DOI: doi.org/10.3897/phytokeys.276.195404 

Abstract

Argostemma baotingense, a new species of Rubiaceae from Hainan Island, southern China, is described. This new species resembles A. bachmaense but can be distinguished by its suberect or creeping stem, linear leaves with a greenish-white abaxial surface, white and glabrous inflorescence, and glabrous calyx. An identification key and photographs of the nine Argostemma species in China are provided.

Key words: Argostemma, new species, taxonomy

Argostemma baotingense.
A. Plant in natural habitat; B. Flowering plant; C. Flowers; D. Calyx; E. Leafy branch, adaxial view; F. Leafy branch, abaxial view; G. Leaves, adaxial view; H. Leaves, abaxial view; I, J. A node with opposite leaves and stipules; K. Flower, apical view; L. Flower, bottom view; M, N. Inflorescence; O. Androecium; P. Pistil.

Argostemma baotingense S.P.Dong & H.B.Yang, sp. nov.

Diagnosis. The new species is morphologically similar to A. bachmaense T.V.Do but differs by the suberect or creeping stem (vs. erect), the linear leaves (vs. oblanceolate to spatulate), glabrous inflorescence (vs. pubescent), glabrous calyx (vs. pubescent). A detailed morphological comparison between the two species is provided in Table 1. Photographs of seven Argostemma species in China have been provided (Fig. 2). A key to all the nine species of Argostemma in China is also provided at the end of the text.

Shu-Peng Dong, Lang-Xing Yuan, Qing-Long Wang and Hu-Biao Yang. 2026. Argostemma baotingense (Rubiaceae), A New Species from Hainan Island, South China. PhytoKeys. 276: 253-260. DOI: doi.org/10.3897/phytokeys.276.195404   [18 Jun 2026]

[Botany • 2026] Polystemma cualense (Apocynaceae: Asclepiadoideae) • A New Species from western Mexico

Polystemma cualense  C.D.Sánchez, S.Islas & A.Black, 

in Sánchez-Sánchez, Islas-Hernández et Black, 2026. 

DOI: doi.org/10.3897/phytokeys.276.176723 

Abstract

A new species of Polystemma is described from the Sierra El Cuale, Jalisco, Mexico. Polystemma cualense is distinguished from its congeners, particularly P. horconesense, by a gynostegial corona higher than the gynostegium, longer external corona lobes, and a black gynostegium. Morphological data were obtained by examining herbarium specimens, consulting digital images from iNaturalist, and reviewing specialized literature. A preliminary conservation assessment based on IUCN criteria indicates that it is a Critically Endangered (CR) species due to its restricted area of occupancy and threats from deforestation, agriculture, and livestock grazing. The discovery of P. cualense increases the known diversity of Polystemma in Jalisco and highlights the floristic importance of the Sierra El Cuale.

Key words: Asclepiadoideae, high diversity, Jalisco, Sierra El Cuale

Polystemma cualense.
A. Complete plant; B. Inflorescence; C. Detail of gynostegium; D. Pollinarium. E. Immature follicle with sepal remnants.

Polystemma cualense C.D.Sánchez, S.Islas & A.Black, sp. nov.

  

Diagnosis. Polystemma cualense resembles P. horconesense in having flowers similar in size and shape. Polystemma cualense differs in having a gynostegial corona higher than the gynostegium (vs. gynostegial corona the same height as the gynostegium), external gynostegial corona lobes 3–4 mm length (vs. 0.5–0.6 mm length) and gynostegium black (vs. gynostegium green-yellowish).

 Cristóbal Daniel Sánchez-Sánchez, Carla Sofía Islas-Hernández and Adam W. Black. 2026. Polystemma cualense (Apocynaceae), A New Species from western Mexico. PhytoKeys. 276: 245-251. DOI: doi.org/10.3897/phytokeys.276.176723   [18 Jun 2026]

 

[Botany • 2018] Lobelia hongiana (Campanulaceae) • A New Species from Guangxi, China

Lobelia hongiana Q.F.Wang & G.W.Hu, 

in Li, Wei, Liu, Chen, Hu et Wang, 2018.

 DOI: doi.org/10.3897/phytokeys.95.20245

Abstract

Lobelia hongiana, a new species of Campanulaceae from Guangxi, South China, is described and illustrated here. This new species is most similar to L. chinensis and L. loochooensis, but differs by its elliptic-obovate or oblanceolate leaf, 2.5–3 mm long greenish-carmine hypanthium, 5 or 6 calyx lobes, purplish-white corolla, with yellowish-green blotches at the base of lower lobes, glabrous filaments, 7–8 mm long broadly obconic capsule. Molecular phylogenetic analysis has been conducted based on ITS and two chloroplast sequences (atpB and rbcL) and 14 taxa in Lobelia are included. L. hongiana is well supported as a new species by the evidence from both morphology and molecular phylogeny.

Keywords: Hypsela, Lobelia chinensis, Lobelia loochooensis, Southern China

 

Photos of Lobelia hongiana Q.F.Wang & G.W.Hu: morphology.
A Habitat B Part of one individual C A stem bearing leaves and a flower D–G Flower viewed from different orientations H–I Fruit viewed from different orientations.

Lobelia hongiana Q.F.Wang & G.W.Hu, sp. nov.

Diagnosis: The new species is distinguished from L. chinensis and L. loochooensis by its elliptic-obovate or oblanceolate leaves, usually sinuate-dentate margin; hypanthium 2.5–3 mm long, greenish-carmine; calyx lobes 5 or 6, shorter than hypanthium; corolla purplish-white, yellowish- green blotches at the base of lower lobes; glabrous filaments; broadly obconic capsule, 7–8 mm long; flowering time from May to July.

 

Distribution and ecology: The new species has been found in Huixian Wetland, Guangxi Zhuang Autonomous Region in China, with only two populations. There is a high probability that L. hongiana is also distributed at adjacent areas, given its vegetative propagation traits. Its living environment is wetland and farmland.

Phenology: The new species was found in flower from May to July.

Etymology: Species epithet, “hongiana”, is in honour of Prof. De-Yuan Hong who made a significant contribution to the authors’ knowledge of Campanulaceae.

 Zhi-Zhong Li, Neng Wei, Yan Liu, Jin-Ming Chen, Guangwan Hu and Qing-Feng Wang. 2018. Lobelia hongiana (Campanulaceae), A New Species from Guangxi, China. PhytoKeys. 95: 27-36.  DOI: doi.org/10.3897/phytokeys.95.20245

[Botany • 2026] Oreocharis sihuiensis (Gesneriaceae) • A critically endangered New Species from Guangdong Province, China

 

Oreocharis sihuiensis  L.B.Ji & F.Wen, 

in  Ji, Wen, Jin, Xu, Li et Tang. 2026. 

四会瑶山苣苔  ||  DOI: doi.org/10.3897/phytokeys.276.190710 

Abstract

Oreocharis sihuiensis sp. nov. (Gesneriaceae) is described from Guangdong Province, China. Morphologically, the flower shape of this new species is similar to that of O. dayaoshanioides, but it can be distinguished by its leaf blade being adaxially densely pubescent, with hairs 0.2–0.5 mm long (vs. adaxially sparsely villous to villous, with hairs longer than 1 mm), lobes of the corolla upper lip subrounded and apex rounded (vs. broadly ovate to orbicular-ovate and apex acute), 3 staminodes (vs. absent or 2), disc margin cleft (vs. subentire), shorter filaments (ca. 6.0 mm long vs. 8.0–12.0 mm long), and shorter capsules (ca. 1.0 cm long vs. ca. 2.0 cm long). Considering its scarce number of individuals, and the presence of severe human disturbance, we preliminarily assess the new species as ‘Critically Endangered’ (CR) according to IUCN Red List Categories and Criteria.

Key words: Medicinal plant, morphology, new taxon, Oreocharis cotinifolia, Oreocharis dayaoshanioides, taxonomy

Oreocharis sihuiensis sp. nov.
A. Habit; B, C. Flowering individuals; D. Leaves, adaxial (left), abaxial (right), and their partially magnified views (a, b. Respectively, showing indumentum); E. Inflorescence; F, G. Flowers, front and lateral view, respectively; H. Longitudinal section of corolla, lower lip (left), upper lip (right) and its partially magnified view (a. Showing indumentum and staminodes); I. Calyx lobes; J. Disc and Pistil; K. Capsules.

Oreocharis sihuiensis sp. nov.
A. Habit; B. Front view of a flower; C. Lateral view of a flower; D. Longitudinal section of corolla; E. Disc and Pistil; F. Capsules; G. Leaf, abaxial surface.

Oreocharis sihuiensis L.B.Ji & F.Wen, sp. nov.

Diagnosis. A species similar to Oreocharis dayaoshanioides Yan Liu & W.B.Xu (in Liu et al. 2012), but can be distinguished from the latter by the adaxial leaf blade being densely pubescent with hairs 0.2–0.5 mm long (vs. sparsely to densely villous, hairs longer than 1 mm), lobes of the corolla upper lip subrounded with a rounded apex (vs. broadly ovate to orbicular-ovate with an acute apex), presence of 3 staminodes (vs. absent or 2), disc margin cleft (vs. subentire), filaments shorter, less than ca. 6.0 mm long (vs. 8.0–12.0 mm), and capsules ca. 1.0 cm long (vs. ca. 2.0 cm). (Table 1, together with the type species of Dayaoshania, now namely Oreocharis cotinifolia).

Etymology. Specific epithet is derived from the type locality, Sihui City.

Vernacular name. Sì Huì Yáo Shān Jù Tái (Chinese pronunciation); 

四会瑶山苣苔 (Chinese name).

Ling-Bo Ji, Fang Wen, Xiu-Hui Jin, Yi-Da Xu, Bo-Heng Li and Bo Tang. 2026. Oreocharis sihuiensis (Gesneriaceae), A critically endangered New Species from Guangdong Province, China. PhytoKeys. 276: 175-182. DOI: doi.org/10.3897/phytokeys.276.190710 [12 Jun 2026]

[Botany • 2026] Oreocharis fulvovillosa (Gesneriaceae) • A New Species from western Yunnan, China

Oreocharis fulvovillosa  M.Q.Han, H.Jiang & Y.Wang,

in Wang, Jiang, Xu et Han, 2026. 

德宏直瓣苣苔  ||  DOI: doi.org/10.3897/phytokeys.276.182136

Abstract

Oreocharis fulvovillosa, a new species of Gesneriaceae, is described and illustrated. This new species has only been discovered on the rock walls of an isolated karst hill at its type locality in Mang City, western Yunnan, China.

Key words: Flora of Yunnan, karst, yellow flowers

 

Oreocharis fulvovillosa sp. nov.
A. Habitat; B. Plant habit in natural habitat; C. Adaxial (left) and abaxial (right) leaf surfaces; D. Petiole with long fulvous indumentum; E. Rhizomatous stem; F. Flower in adaxial view; G. Flower in abaxial view; H. Flower in side view; I. Flower longitudinally cut, male stage with immature pistil; J. Flower transversely cut, male stage with immature pistil; K. Immature pistil and stamens with dehisced anthers cohering in pairs; L. Flower in front view; M. Capsules at different developmental stages: two immature capsules (left) and two dehisced capsules from the previous year (right); N. Pistils at different developmental stages: left, at flower opening with immature stigma; middle and right, at stigma maturity; O. Transverse sections of ovaries, all arranged with the dorsal calyx lobe positioned upwards: upper image, ovary at stigma maturity; lower images, ovary with immature stigma, showing transverse sections of the upper part of the ovary (left) and the lower part of the ovary (right).

Oreocharis fulvovillosa M.Q.Han, H.Jiang & Y.Wang, sp. nov.

 

Diagnosis. The new species is most similar to Oreocharis bullata, sharing yellow corollas and bullate leaf blades, but differs in having crenulate leaf margins (vs. double dentate), a slender corolla tube ca. 1 cm long (vs. tubular, ca. 2.7 cm long), and shorter capsules 1–1.9 cm long (vs. 3.0–4.2 cm long). It is also similar to Oreocharis fulva in corolla shape and colour but differs in having bullate leaf blades (vs. not bullate) and crenulate margins (vs. serrate to crenate).

Etymology. The epithet refers to the fulvous (yellowish) colour of the long, soft hairs on the petioles.

Vernacular name. Chinese Mandarin: dé hóng zhí bàn jù tái, (德宏直瓣苣苔).

Yang Wang, Hong Jiang, Bo Xu and Meng-Qi Han. 2026. Oreocharis fulvovillosa (Gesneriaceae), A New Species from western Yunnan, China. PhytoKeys. 276: 17-23.  DOI: doi.org/10.3897/phytokeys.276.182136 [08-06-2026]

 

[Botany • 2026] Primula xingyiensis (Primulaceae) • A New Species from Guizhou, China

Primula xingyiensis  Z.K.Wu & C.Y.Deng,

in Shi, Deng, Lang, Liu et Wu, 2026.

DOI: doi.org/10.3897/phytokeys.276.195710

Abstract

Primula xingyiensis Z.K.Wu & C.Y.Deng, a new species of Primulaceae from Guizhou, China, is described and illustrated. Morphological evidence places P. xingyiensis within Primula sect. Carolinella, a section characterised by plants completely efarinose but bearing pubescent or glandular hairs; leaf base cordate to rounded, rarely broadly cuneate, with distinct petioles; calyx campanulate or narrowly campanulate, longer than its diameter, split to 1/3–1/2 of its length; and capsule oblong, dehiscing nearly calyptrate at maturity. The new species is distinguished by its gracile habit, shortened stem, small leaves with long villous hairs on both surfaces, long-styled homostylous flowers, and a corolla that is 7–8 times as long as the calyx. Information on the distribution, morphological comparisons with closely related species, and the conservation status of the new species is also provided, along with a key to the known species of Primula sect. Carolinella.

Key words: Conservation status, diversity, Guizhou, nomenclature, taxonomy, xing yi bao chun

Primula xingyiensis sp. nov.
  A, B. Habitat; C, D. Habit during flowering; E. Leaves, the left: adaxial surface, the right: abaxial surface; F. Scape; G. Frontal view of flower; H. Dissected corolla showing anthers and stigmas; I. Capsule.

Photographed by Zhikun Wu.

Two morphologically similar taxa and Primula xingyiensis.
A. Holotype of P. calyptrata (X Gong 02815, KUN!); B. Isotype of P. intanoensis (M. Tagawa, K. Iwatsuki & N. Fukuoka 2863, HUH!); C. Holotype of Primula xingyiensis (ZKWU2025210, KUN!);
D. P. calyptrata; E, F. P. xingyiensis; D–F. Photographed by Zhikun Wu.

 Xiang-Ting Shi, Chao-Yi Deng, Yuan-Xing Lang, Zeng-Cai Liu and Zhi-Kun Wu. 2026. Primula xingyiensis (Primulaceae), A New Species in Primula sect. Carolinella from Guizhou, China. PhytoKeys. 276: 1-11. DOI: doi.org/10.3897/phytokeys.276.195710 [5 Jun 2026]

[Botany • 2026] Ophiorrhiza xishuiensis (Rubiaceae) • A New Species endemic to Guizhou, Sichuan, and Chongqing, China

 

Ophiorrhiza xishuiensis Sheng H.Tang, Jia W.Yang & X.Z.He,   

in He, Dai, Xu, Yang et Tang, 2026. 

 DOI: doi.org/10.3897/phytokeys.275.189435 

Abstract

A new species in Rubiaceae, Ophiorrhiza xishuiensis, is described from China. The new species is endemic to the Danxia landform at the juncture of Guizhou Province, Sichuan Province, and Chongqing City. It is a herb with a 1–7 cm long rooting stem, 3–11 nodes, and most leaves arranged in markedly unequal pairs. It has a somewhat inequilateral leaf blade base, a congested-cymose inflorescence, and well-developed bracteoles. We investigated two populations in Guizhou, China. The new taxon has been collected or photographed by others in Sichuan and Chongqing, China, and misidentified as O. japonica, O. umbricola, O. cantonensis, or O. chinensis. An identification key to O. xishuiensis and morphologically similar species is provided.

Key words: Danxia landform, flora of China, new taxon, Ophiorrhiza

Habitat of Ophiorrhiza xishuiensis sp. nov.
A, B. Population of Sanchahe Town, Xishui County, China; C, D. Population of Baoyuan Town, Chishui City, China

 (Photographed by Sheng-Hu Tang and Xuan-Ze He).

Ophiorrhiza xishuiensis Sheng H.Tang, Jia W.Yang & X.Z.He, sp. nov.

 

Diagnosis. The new species is most similar to O. japonica, O. guizhouensis, and O. chinensis by the length of the stipules, calyx lobes and corolla tube, the shape of the corolla, and the distribution areas and altitudes. It differs from O. japonica and O. guizhouensis by the 1–7 cm long rooting stems (vs. 10–30 cm, or longer), the fact that most leaves are arranged in markedly unequal (vs. subequal) pairs, the style reaching above (vs. below) the middle of the tube in the short-styled flowers, and the glabrous (vs. pubescent) style in the long-styled flowers. It is distinct from O. chinensis by the congested-cymose (vs. paniculiform to cymose) inflorescences, the well-developed and persistent (vs. absent or reduced and caducous) bracteoles, and the glabrous (vs. pubescent) style in the long-styled flowers.

 Xuan-Ze He, Zheng-Xian Dai, Jian Xu, Jia-Wen Yang and Sheng-Hu Tang. 2026. Ophiorrhiza xishuiensis (Rubiaceae), A New Species endemic to Guizhou, Sichuan, and Chongqing, China. PhytoKeys. 275: 163-176. DOI: doi.org/10.3897/phytokeys.275.189435 [29 May 2026]

[Botany • 2026] Ophiorrhiza bibracteata (Rubiaceae) • A New Species from Guangxi, China

Ophiorrhiza bibracteata Y.Nong & G.Y.Wei, 

in Nong, G.-Y. Wei, H.-Y. Wei, Long, Liu, Feng et Qin, 2026.

金钟山蛇根草  ||  DOI: doi.org/10.3897/phytokeys.275.189773

Abstract

Ophiorrhiza bibracteata (Rubiaceae), a new species from northwest Guangxi, China, is described and illustrated. It can be distinguished from its allies O. mitchelloides, O. nanlingensis and O. grandibracteolata by the shape and size of the bracts (ovate, 8–11 mm long) and the shape and size of the calyx lobes (triangular, 0.8–1.0 mm long, glabrous, with glands between the lobes). According to the IUCN Red List Categories and Criteria, the new species is assessed as Data Deficient (DD) until more information becomes available.

Key words: Morphology, new species, Ophiorrhiza, taxonomy

Ophiorrhiza bibracteata Y.Nong & G.Y.Wei.
A, B. Habit; C, D. Flowering plant; E. Brevistylous flower (front view); F. Flower (lateral view); G. Dissected brevistylous flower; H. Dissected longistylous flower; I. Ovary, calyx, style and stigma of longistylous (left) and brevistylous (right) flower; J. Ovary, calyx, style and stigma of brevistylous flower; K. Stipule; L. Bracts and flower bud; M. Leaf, adaxial surface; N. Leaf, abaxial surface; O. Fruiting plant; P. Capsules and bracts (images captured with a Nikon D850 camera).

Ophiorrhiza bibracteata Y.Nong & G.Y.Wei, sp. nov. 

Diagnosis. Ophiorrhiza bibracteata is similar to O. mitchelloides (Masam.) H.S.Lo, but differs in the following characters: the number of secondary veins (5–7 pairs in O. bibracteata vs. 3–5 pairs), the shape and size of the bracts (ovate, 8–11 mm long vs. linear, 4–8 mm long), the shape and size of the calyx lobes (triangular, 0.8–1.0 mm long, glabrous, with glands between the lobes vs. linear, ca 1.4 mm long, glabrescent or ciliate, without glands) and the nature of the flowers (distylous vs. monostylous).

Etymology. The specific epithet is derived from the Latin, bibracteata, meaning “two bracts” and referring to the two persistent ovate bracts of the new species.

Chinese name. 金钟山蛇根草 (jīn zhōng shān shé gēn căo).

 You Nong, Gui-Yuan Wei, Hai-Yong Wei, Lie Long, Zhi-Rong Liu, Bin Feng and Ting Qin. 2026. Ophiorrhiza bibracteata (Rubiaceae), A New Species from Guangxi, China.  PhytoKeys. 275: 151-161. DOI: doi.org/10.3897/phytokeys.275.189773 [29 May 2026]

[Botany • 2026] Dioon nuusaviorum (Zamiaceae) • A striking New Species from pine and pine-oak forest of Guerrero, Mexico

Dioon nuusaviorum Mart.-Domínguez, Nic.-Mor. & D.W.Stev.,   

in Martínez-Domínguez, Nicolalde-Morejón, Stevenson, Lorea-Hernández et Vergara-Silva, 2026.

DOI: doi.org/10.3897/phytokeys.274.173907 

Abstract

Taxonomic studies in cycad genera using multiple approaches have refined the delimitation of many species. In the case of Dioon Lindl., a Mesoamerican genus, a reliable classification has been achieved through taxonomic work carried out since the description of the genus and pioneering studies in Mexico during the 1980–90s. Here, we describe a new species from Guerrero based on evidence collected from populations encountered during fieldwork carried out in 2019. These populations had previously been considered morphologically similar to Dioon holmgrenii De Luca, Sabato & Vázq. Torres, which has a markedly disjunct distribution in Oaxaca. After studying herbarium specimens and making extensive observations on vegetative and reproductive structures from different populations in Oaxaca, we have concluded that the disjunct populations analysed in 2019 represent a distinct and new species of Dioon, separate from the two most phenotypically similar species—namely, D. stevensonii Nic.-Mor. & Vovides and D. holmgrenii. A key to geographically proximal and morphologically similar species as well as to the other species occurring in Guerrero and Oaxaca States is also presented. The proposed new species, Dioon nuusaviorum Mart.-Domínguez, Nic.-Mor. & D.W.Stev., is endemic to Guerrero and inhabits pine and pine-oak forest. Its conservation status, assessed on the based IUCN guidelines and criteria, qualifies as Endangered.

Key words: Cycadales, cycads, Mesoamerica, Neotropics, Sierra Madre del Sur

Dioon nuusaviorum sp. nov.
A. Ovulate strobilus; B. Megasporophyll; C. Basal scale of megasporophyll; D. Microsporophyll; E. Leaflets variation; F. Cataphylls; G. Seeds variation; H. New leaves; I. Leaves at emergence; J. Leaf at maturity.

Dioon nuusaviorum sp. nov., in habitat.
 A. Ovuliferous plant in habitat; B. Eumaeus sp; C. Population in La Trinidad; D. Vegetation view; E. Ovulate strobilus at maturity in habitat. 

Dioon nuusaviorum Mart.-Domínguez, Nic.-Mor. & D.W.Stev., sp. nov.

 

Diagnosis. Dioon nuusaviorum sp. nov. differs from D. holmgrenii by having leaflets imbricate to strongly imbricate, each with three to six long marginal teeth (0.26–0.37 cm long), a margin of the leaflets curved acroscopically, microsporophylls with an acuminate apex and megasporophylls with an apiculate apex. In contrast, D. holmgrenii has non-imbricate leaflets (generally a 0.2–1.0 cm between leaflets) with two to five short teeth on the distal margin (0.15–0.29 cm long), a margin of the leaflets straight, microsporophylls with an acute apex and megasporophylls with an acuminate apex. In comparison to D. stevensonii, this new species differs by its light green leaflets at emergence (vs golden), leaflet imbricate to strongly imbricate (vs not imbricate), acuminate apex of microsporophylls (vs acute), tomentose indument and narrowly-triangular megasporophylls at maturity (vs pubescent at base or scarcely pubescent and triangular).

Comparison of leaflets of Dioon holmgrenii, D. stevensonii and Dioon nuusaviorum sp. nov.
A. D. stevensonii; B. D. holmgrenii; C. Dioon nuusaviorum sp. nov.;
D. D. stevensonii (F. Nicolalde-Morejón et al. 1554, CIB); E. D. holmgrenii (Brigada T. Walters s/n [3997], XAL); F. D. holmgrenii (F. Nicolalde-Morejón et al. 1468, XAL); G. Dioon nuusaviorum sp. nov. (L. Martínez-Domínguez et al. 1745, CIB).

 Lilí Martínez-Domínguez, Fernando Nicolalde-Morejón, Dennis Wm. Stevenson, Francisco G. Lorea-Hernández and Francisco Vergara-Silva. 2026. A striking New Species of Dioon (Zamiaceae) from pine and pine-oak forest of Guerrero, Mexico. PhytoKeys. 274: 229-245. DOI: doi.org/10.3897/phytokeys.274.173907 [11 May 2026]

[Botany • 2026] Rhododendron jiucaipingensis (Ericaceae, subgen. Hymenanthes) • A New Species from Guizhou, China

Rhododendron jiucaipingensis Jian Xu & M. T. An, 

in Hu, Xu, An, Yu et Lu, 2026. 

韭菜坪杜鹃  ||  DOI: doi.org/10.3897/phytokeys.275.183519

Abstract

Rhododendron jiucaipingensis Jian Xu & M. T. An, sp. nov. (Ericaceae), a new species of R. subgen. Hymenanthes, subsect. Argyrophylla, from northwestern Guizhou, China, is described and illustrated. It is an evergreen shrub 1.5–3.0 m tall, characterized by green, densely white-tomentose current-year branchlets, leaves crowded at branch apices (5.5–9.5 × 2.5–4.0 cm) with 8–11 pairs of lateral veins, 10 stamens, and cylindric capsules 1.2–2.0 cm long. The new species is morphologically most similar to R. hypoglaucum and R. argyrophyllum, but it is readily distinguished by having densely white-tomentose current-year branchlets, fewer lateral veins (8–11 pairs), a double-layered white indumentum on the abaxial surfaces of young leaves, and 10 stamens. Phylogenetic analysis based on a whole-genome SNP dataset robustly resolves R. jiucaipingensis as a distinct lineage within subsect. Argyrophylla, positioned as sister to the monophyletic clade of five congeneric species with high support (SH-aLRT = 100%, UFBoot = 100%). This molecular evidence, congruent with diagnostic morphological characters, supports the recognition of R. jiucaipingensis as a species new to science.

Key words: Ericaceae, Flora of China, morphology, phylogeny, taxonomy

Rhododendron jiucaipingensis Jian Xu & M. T. An, sp. nov.
 A. Cliff habitat; B. Older branches; C. Current-year branchlet and its dense white tomentum (inset); D. Mature leaf and its short, brown tomentum on the abaxial surface (inset); E. Adaxial surface of young leaf; F. Abaxial surface of young leaf and long white glandular hairs of it (inset); G. Flowering plant; H. Anatomical diagram of the flower and leaf; I. Stamens and their white stiff hairs at the filament base (inset); J. Calyx; K. Ovary; L. Capsule and its colorless stellate hairs (inset); M. Capsule in longitudinal section (Photographs by Jian Xu)

Diagnosis. Rhododendron jiucaipingensis belongs to subgen. Hymenanthes and is similar in morphology to R. hypoglaucum and R. argyrophyllum, but can be distinguished from R. hypoglaucum by its current-year branchlets and young petioles being densely covered with indumentum (vs. glabrous), and its pedicels being densely white-villous (vs. glabrous). It further differs from R. hypoglaucum in having fewer lateral veins (8–11 pairs vs. 10–14 pairs), an ovary sparsely covered with colorless stellate hairs (vs. glabrous), and typically 7-loculed capsules (vs. 6-loculed). Compared to R. argyrophyllum, the new species is distinguished by its acuminate leaf apex (vs. obtuse), fewer stamens (10 vs. 12–15), and the presence of colorless stellate hairs on the ovary (vs. white short tomentum). Additionally, R. jiucaipingensis is characterized by its restricted cliff habitat at higher elevations (2,400–2,700 m).

Etymology. The specific epithet jiucaipingensis refers to the type locality, Xingfa Township (Jiucaiping), Hezhang County, Bijie City, Guizhou, China.

Vernacular name. The Chinese name is jiǔ cài píng dù juān (韭菜坪杜鹃).

Hong-Fen Hu, Jian Xu, Ming-Tai An, Jiang-Hong Yu, Xing Lu. 2026. Rhododendron jiucaipingensis (Ericaceae), A New Species from Guizhou, China. PhytoKeys 275: 15-26. DOI: doi.org/10.3897/phytokeys.275.183519 [19 May 2026]