taxonID	type	description	language	source
03CDE6126A1EFF87FF1EFD3F6E7C1788.taxon	diagnosis	Diagnosis: — Ophiopogon rugosus is distinguishable from all other members of the genus by the leaf blades with many small wrinkles tesselate on the adaxial surface. In its habit and somewhat woody / rigid roots, the new species may look similar to O. xylorrhizus F. T. Wang & L. K. Dai in Wang & Tang (1978: 252), but clearly differs mainly by the smaller (4.3 – 8.7 vs. 11 – 16 cm long), adaxially wrinkled (vs. non-wrinkled, flat), abaxially whitish (glaucous) (vs. pale green) leaf blades with fewer (up to 12 vs. numerous) longitudinal parallel veins, and shorter filaments (0.1 – 0.2 vs. 1 mm long).	en	Tanaka, Noriyuki, Averyanov, Leonid V., Nguyen, Cuong Huu, Maisak, Tatiana V., Nguyen, Duong Tuan, Dai, Hai Vo, Chu, Quan Ngoc (2025): Ophiopogon rugosus (Asparagaceae), a new species from northeastern Vietnam. Phytotaxa 721 (2): 167-174, DOI: 10.11646/phytotaxa.721.2.4, URL: https://doi.org/10.11646/phytotaxa.721.2.4
03CDE6126A1EFF87FF1EFD3F6E7C1788.taxon	materials_examined	Type: — VIETNAM. Bac Kan Province [presently, Thai Nguyen Province]: Ba Be District, Ba Be National Park, primary or old secondary evergreen broad-leaved forest on very steep rocky slopes composed of white crystalline marble-like highly eroded limestone around point 22 º 27 ’ 26 ’’ N 105 º 36 ’ 12 ’ E at elevation of 600 – 800 m a. s. l., terrestrial herb in shady rocky place, locally common, 30 October 2023, Nguyen Huu Cuong, Chu Ngoc Quan, L. Averyanov, Nguyen Van Ly, T. Maisak, AL 2384. Flowered in culture on 14 July 2025, flowers pure white, anthers light yellow-greenish, L. Averyanov, T. Maisak, AL 2384 (holotype: LE LE 01282499 // Virtual herbarium of Komarov Botanical Institute RAS — http: // re. herbariumle. ru / 01282499). Images of the living state of the holotype are archived as: LE 01203414 // Virtual herbarium of Komarov Botanical Institute RAS — http: // re. herbariumle. ru / 01203414).	en	Tanaka, Noriyuki, Averyanov, Leonid V., Nguyen, Cuong Huu, Maisak, Tatiana V., Nguyen, Duong Tuan, Dai, Hai Vo, Chu, Quan Ngoc (2025): Ophiopogon rugosus (Asparagaceae), a new species from northeastern Vietnam. Phytotaxa 721 (2): 167-174, DOI: 10.11646/phytotaxa.721.2.4, URL: https://doi.org/10.11646/phytotaxa.721.2.4
03CDE6126A1EFF87FF1EFD3F6E7C1788.taxon	etymology	Etymology: — The specific epithet refers to the adaxially wrinkled leaf blades which distinguishes the new species from all other congeners.	en	Tanaka, Noriyuki, Averyanov, Leonid V., Nguyen, Cuong Huu, Maisak, Tatiana V., Nguyen, Duong Tuan, Dai, Hai Vo, Chu, Quan Ngoc (2025): Ophiopogon rugosus (Asparagaceae), a new species from northeastern Vietnam. Phytotaxa 721 (2): 167-174, DOI: 10.11646/phytotaxa.721.2.4, URL: https://doi.org/10.11646/phytotaxa.721.2.4
03CDE6126A1EFF87FF1EFD3F6E7C1788.taxon	description	Description: — Plant terrestrial, rhizomatous, glabrous, evergreen, perennial. Rhizome subterete, straight or curved, up to 3.3 cm long, 3 – 5 mm in diameter, bearing roots. Roots somewhat woody, rigid, cord-like, brown, up to 2.5 mm in diameter. Stem erect or suberect, 0.9 – 2.4 cm long, covered with petioles of foliage leaves and sheath leaves; sheath leaves broadly ovate to narrowly triangular, up to 2.5 cm long, obtuse, subacute or subacuminate, margins scarious, withering early. Foliage leaves 6 – 19 per plant, tufted, distinctly petiolate; petiole linear, 4.3 – 8.7 cm long, 2 – 2.8 mm wide, abaxially rounded (in cross section), adaxially somewhat flat; blade elliptic, 5 – 10.8 cm long, (1.3) 2 – 3.7 cm wide, equal or subequal in length to petiole, proximally attenuate, oblique, narrowly decurrent to petiole, entire, distally acuminate, adaxially glossy, green or deep green, wrinkled in vertical and horizontal arrays, abaxially white-glaucous, longitudinal parallel veins 5 – 11 (12) (5 of which slightly more distinct) including midvein and excluding outermost veins along extreme margins, pinnate in basal part of blade, converging at apex of blade, green; transversal veinlets numerous, adaxially distinct (slightly raised), closely spaced nearly in parallel, forming a checkered (tesselate) network with longitudinal veins. Flowering stem (peduncle and inflorescence rachis) 11.8 – 20 cm long (including stem in fruit), slightly arching, distally exceeding foliage leaves, complanate, longitudinally ribbed, pale purple; peduncle 5.5 – 7.5 cm long, 1.7 – 2.2 mm wide, ebracteate (excepting base); inflorescence reduced thyrsoid (or pseudo-racemose); rachis 5.5 – 12.5 cm long, up to 2 mm wide. Flower 1 – 2 (3) in axils of bracts, secund, campanulate with moderately (Fig. 1) or widely (Fig. 2) expanded perianth segments, directed obliquely downward, limb 4.2 – 8 mm across, actinomorphic, bisexual, adichogamous, pedicellate; pedicels ascending, straight, terete, up to 5 mm long, 0.8 mm in diameter, terminally jointed to basal stalky part of flower which is 2 – 4 mm long and curved (entire stalk including stalky floral part articulated medially or submedially), subtended by 2 bracts (1 outer bract and 1 inner bracteole) which are triangular, ovate or lanceolate, acute to strongly acuminate, antrorse, margins broadly scarious, bract up to 7 mm long, 4 mm wide at base, bracteole up to 3.7 mm long, 2.5 mm wide. Perianth distally 6 - lobed, white, distally slightly tinged beige or greenish yellow; basal united part funnel-shaped, tapering below to a curved stalk; lobes in 2 close whorls of 3, nearly straight (Fig. 1) or recurved distally (Fig. 2), 1 - veined; outer lobes ovate or narrowly ovate, 4 – 4.5 mm long, 2 – 2.5 mm wide; inner lobes triangular ovate, 4 – 4.3 mm long, 1.9 – 2 mm wide (slightly narrower than outer lobes). Stamens 6, arranged almost in 1 whorl, together (androecium) connivent distally surrounding style; filaments very short (0.1 – 0.2 mm long below bottom of anther sacs), 0.6 – 1 mm wide at base, incrassate, white; anthers dorsi-basifixed, narrowly triangular to triangular-lanceolate, 2.8 – 3 mm long, 1 mm wide at base, thinning above, latrorsely introrse, dehiscent longitudinally, pale greenish yellow; connective abaxially dilated toward base; pollen pale yellow. Pistil 1, 3 - carpellate, white; ovary inferior, shortly obconic, 3 - loculate; ovules 2 per locule; style arising from apical slightly concave center of ovary, strict, subulate, 4.8 – 5 mm long, 0.4 – 0.5 mm in diameter in middle, distal part exserted from perianth; stigma minutely 3 - lobed, 0.2 – 0.3 mm across. Immature seeds ellipsoidal, 8 – 12 mm long, 6 – 8 mm in diameter, seed coat pale green, fleshy, basally often with remnants of withered perianth.	en	Tanaka, Noriyuki, Averyanov, Leonid V., Nguyen, Cuong Huu, Maisak, Tatiana V., Nguyen, Duong Tuan, Dai, Hai Vo, Chu, Quan Ngoc (2025): Ophiopogon rugosus (Asparagaceae), a new species from northeastern Vietnam. Phytotaxa 721 (2): 167-174, DOI: 10.11646/phytotaxa.721.2.4, URL: https://doi.org/10.11646/phytotaxa.721.2.4
03CDE6126A1EFF87FF1EFD3F6E7C1788.taxon	biology_ecology	Ecology and phenology: — The new species occurs as a terrestrial or lithophytic perennial herb in primary or old secondary evergreen broad-leaved forests at elevations of 600 – 800 m a. s. l. It inhabits shady rocky valley between limestone hills or very steep rocky slopes composed of white to gray solid marble-like highly eroded limestone. Flowers in July under cultivation. Immature seeds in October – November. Conservation status: — To our knowledge, Ophiopogon rugosus is confined strongly to a very narrow range (Ba Be National Park in Thai Nguyen Province) in NE Vietnam. In this context its sole, restricted habitat itself is extremely precious enough for perpetual conservation. Though still lacking in detailed data on the abundance and distribution, the new species is assessed here as Least Concern (LC), following the guidelines of IUCN (2024), as it is locally common in the forest of the National Park where flora and fauna there is officially protected. Toward better protection of the species, we need to further investigate its specific ecological requirements.	en	Tanaka, Noriyuki, Averyanov, Leonid V., Nguyen, Cuong Huu, Maisak, Tatiana V., Nguyen, Duong Tuan, Dai, Hai Vo, Chu, Quan Ngoc (2025): Ophiopogon rugosus (Asparagaceae), a new species from northeastern Vietnam. Phytotaxa 721 (2): 167-174, DOI: 10.11646/phytotaxa.721.2.4, URL: https://doi.org/10.11646/phytotaxa.721.2.4
03CDE6126A1EFF87FF1EFD3F6E7C1788.taxon	materials_examined	Additional specimens examined (paratypes): — VIETNAM, Thai Nguyen Province [Bac Kan Province]: Ba Be National Park, primary or old secondary evergreen broad-leaved forest on very steep rocky slopes composed of white crystalline marble-like highly eroded limestone around point 22 º 27 ’ 26 ’’ N 105 º 36 ’ 12 ’ E at elevation of 600 – 800 m a. s. l., terrestrial herb in shady rocky place, locally common, 30 October 2023, Nguyen Huu Cuong, Chu Ngoc Quan, L. Averyanov, Nguyen Van Ly, T. Maisak, AL 2384, LE 01254058 // Virtual herbarium of Komarov Botanical Institute RAS — http: // re. herbariumle. ru / 01254058). Images of living plants of the same collection AL 2384 are archived as: LE, 01124495 // Virtual herbarium of Komarov Botanical Institute RAS — http: // re. herbariumle. ru / 01124495. VIETNAM, Thai Nguyen Province [Bac Kan Province]: Nam Mau Commune, Nam Dai Village, dry evergreen broad-leaved forest on steep rocky slopes composed of white to gray crystalline marble-like limestone around point 22 º 25 ’ 20 ’’ N 105 º 35 ’ 03 ’ E at elevation of about 650 m a. s. l., terrestrial herb on steep shady rocky slope, leaves dark green to almost black, rare, 18 October 2023, Nguyen Huu Cuong, Chu Ngoc Quan, L. Averyanov, Nguyen Van Ly, T. Maisak, AL 2313, LE 01254216 // Virtual herbarium of Komarov Botanical Institute RAS — http: // re. herbariumle. ru / 01254216. Images of the living state of this specimen are archived as LE 01124426 // Virtual herbarium of Komarov Botanical Institute RAS — http: // re. herbariumle. ru / 01124426. VIETNAM, Thai Nguyen Province [Bac Kan Province]: Nam Mau Commune, central part of Ba Be National Park, rather dry evergreen broad-leaved old secondary forest with domination of Burretiodendron hsienmu and Streblus asper on crystalline highly eroded rocky limestone at elevation 600 – 750 m a. s. l., terrestrial or lithophytic herb in wet humid rocky valley between limestone hills, occasional, 16 November 2022, Nguyen Huu Cuong, Cao Xuan Hai, L. Averyanov, T. Maisak, AL 1665. Flowered in culture on 14 July 2025, flowers pure white, anthers light yellow-greenish, L. Averyanov, T. Maisak, AL 1665. LE 01282500 // Virtual herbarium of Komarov Botanical Institute RAS — http: // re. herbariumle. ru / 01282500. Images of the living state of this specimen are archived as: LE 01203413 // Virtual herbarium of Komarov Botanical Institute RAS — http: // re. herbariumle. ru / 01203413. VIETNAM, Thai Nguyen Province [Bac Kan Province]: Nam Mau Commune, central part of Ba Be National Park, rather dray evergreen broad-leaved old secondary forest with domination of Burretiodendron hsienmu and Streblus asper on crystalline highly eroded rocky limestone at elevation 600 – 750 m a. s. l., terrestrial or lithophytic herb in wet humid rocky valley between limestone hills, occasional, 16 November 2022, Nguyen Huu Cuong, Cao Xuan Hai, L. Averyanov, T. Maisak, AL 1665, LE 01169987 // Virtual herbarium of Komarov Botanical Institute RAS — http: // re. herbariumle. ru / 01169987. Images of the living state of this specimen are archived as: LE 01123655 // Virtual herbarium of Komarov Botanical Institute RAS — http: // re. herbariumle. ru / 01123655.	en	Tanaka, Noriyuki, Averyanov, Leonid V., Nguyen, Cuong Huu, Maisak, Tatiana V., Nguyen, Duong Tuan, Dai, Hai Vo, Chu, Quan Ngoc (2025): Ophiopogon rugosus (Asparagaceae), a new species from northeastern Vietnam. Phytotaxa 721 (2): 167-174, DOI: 10.11646/phytotaxa.721.2.4, URL: https://doi.org/10.11646/phytotaxa.721.2.4
03CDE6126A1EFF87FF1EFD3F6E7C1788.taxon	distribution	Distribution: — Currently known only from Ba Be National Park, northern part of Thai Nguyen Province (formerly Bac Kan Province), NE Vietnam. Taxonomic relationships: — Having basal, fasciculate broad leaf blades with a conspicuous petiole, Ophiopogon rugosus is referable to Ophiopogon sect. Peliosanthoides F. T. Wang & L. K. Dai in Wang & Tang (1978: 251) or to Ophiopogon ser. Peliosanthoides (F. T. Wang & L. K. Dai) H. Li & Y. P. Yang in Yang & Li (1990: 81). Many of the species of this section or series are concentratedly distributed in SW China (Wang & Tang 1978) and NE Indochina (Rodriguez 1929, 1934, Tanaka 1999, Averyanov et al. 2020). These regions may hence be deemed at least as the current center or cradle of the diversification of this plant group. Ophiopogon rugosus is clearly distinguishable from all other members of the genus by its leaf blades wrinkled rather regularly in vertical and horizontal arrays on the adaxial surface. This unique trait of foliar rugosity appears strongly related to the distinctly tesselate veins of the blades. Its evolutionary or adaptive significance is, however, unknown. Apart from this trait, the new species can also be distinguished by several other respects. Just to avoid repetition, we omit to further mention the same trait (adaxially wrinkled blades of O. rugosus) in the below comparisons with similar species of the above section or series.	en	Tanaka, Noriyuki, Averyanov, Leonid V., Nguyen, Cuong Huu, Maisak, Tatiana V., Nguyen, Duong Tuan, Dai, Hai Vo, Chu, Quan Ngoc (2025): Ophiopogon rugosus (Asparagaceae), a new species from northeastern Vietnam. Phytotaxa 721 (2): 167-174, DOI: 10.11646/phytotaxa.721.2.4, URL: https://doi.org/10.11646/phytotaxa.721.2.4
