Vietnam is located in the east of Indochina Peninsula, bordering Guangxi and Yunnan of China to the north, Laos and Cambodia to the west. Affected by the tropical monsoon climate, it has high annual rainfall and humidity, and is one of the16 countries with high biodiversity in the world. There are a total of 874 species of lycopsids and ferns in 38 families and 116 genera (POWO, 2024) , and there have been frequent reports of new species (Parris et al., 2015; Pham et al., 2022) and new recorded species (Wu et al., 2005, 2006, 2012; Chen et al., 2020, 2021, 2023; Wei et al., 2022) in recent years. While examining photographs and specimens of lycopsids and ferns collected in northern Vietnam, the authors identified two species (Adiantum longzhouensis and Lepisorus bicolor) as newly recorded species in Vietnam (Wang et al., 2017) . Through consulting relevant materials and specimens, it was found that Adiantum longzhouensis had been collected in Vietnam before (Wei et al., 2022) , the reported A. juxtapositum Ching should be the misidentification of A. longzhouensis. Phlegmariurus guangdongensis was also a newly recorded species from Vietnam (Wu et al., 2013; Nong et al., 2016) . It is now reported together to increase the biodiversity inventory of Vietnam. The voucher specimens were kept in the Herbarium of Kunming Institute of Botany, Chinese Academy of Sciences (KUN) , Herbarium of Institute of Botany, Chinese Academy of Sciences (PE) and Herbarium of Guangxi Forestry Research Institute (GXFI) .

Phlegmariurus guangdongensis Ching in Acta Bot. Yunnan.4（2）: 123.1982; Li Bing Zhang et H. S. Kung in Acta Phytotax. Sin.38（1）: 28.2000，et in Fl. Reipubl. Popularis Sin.6（3）: 35.2004; Li Bing Zhang et Kunio Iwatsuki in Flora of China Vol.2–3: 22.2013. —— Huperzia guangdongensis（Ching）Holub in Folia Geobot. Phytotax.20: 73.1985. 广东马尾杉（Fig.1: A-C）

Type: China. Guangdong, Xinyi, 14 Apr.1931, S. P. Ko 51291 (Holotype: PE!; Isotypes: PE!, IBK!, SZ!) .

Epiphytic on rocks under forests. Stems caespitose, 1-3-forked. Leaves spirally arranged, sporophylls and trophophylls distinctly dimorphic. Trophophylls elliptic-lanceolate, obliquely spreading, included angle with stem about 40°, length-width ratio about 5∶1, base cuneate, sessile, apex acuminate, margin entire. Sporangium spikes terminal; sporophylls ovate or ovate-triangular, acuminate or acute. Sporangia in axils of sporophylls, reniform, 2-valved, yellow.

Specimens examined: Lam Dong Prov., Lac Duong Distr., Da Chays Commune, Hon Ginomountainous range, ca.1 530 m, epiphyte in evergreen seasonal tropical mixte broad, 29 Oct.2006, S. G. Wuet P. K. Loc etc. WP1194 (KUN) ; Lam Dong Prov., Lac Duong Distr., Da Chays Commune, BiDoup mountainous range, around point, ca.1 900-2 000 m, epiphyte in evergreen seasonal tropical broad-leaved, 31 Oct.2006, S. G. Wuet P. K. Loc etc. WP1264 (KUN) ; Lam Dong Prov., Lac Duong Distr., Cong Troi FPStation, around point, ca.1 680-1 760 m, epiphyte in evergreen seasonal tropical broad-leaved, 7 Nov.2006, S. G. Wuet P. K. Loc etc. WP1443 (KUN) .

Distribution: Type specimens were collected from Guangdong and distributed in Guangxi, Guangdong and Hainan of China. Epiphytic on tree trunks or rock walls. Newly recorded species for Vietnam.

Notes: P. guangdongensis is similar to P. fordii and P. henryi, difference is that the sporophylls and trophophylls distinctly dimorphic and the middle trophophylls are sessile. It is also similar to P. phlegmaria, except that the stems of P. guangdongensis are1 to 2 dichotomous branches, the plants are nearly erect or inclined, and the trophophylls are lanceolate or elliptical lanceolate, with a length-width ratio less than 7∶1.

Adiantum longzhouensis A. H. Wang，F. G. Wang &F. W. Xing in PLoS ONE 12（4）: e0172729（14）.2017. 龙州铁线蕨（Fig.1: D-F）

Type: China. Guangxi, Daxin County, Baoxu Town, Jing-Yang-Cun Primary School, 10 Jun.2014, WAH017 (Holotype: IBSC!; Isotype: IBSC!) .

Plants epilithic, about 14 cm tall. Rhizomes short, erect, covered with lanceolate and black brown scales, scales margin entire. Leaves clustered, about 5-11 cm long, about 1 mm thick, glossy and smooth. Lamina1-pinnate, odd-pinnate or paripinnate, pinnae9-14, opposite, rarely alternate; Pinnule obdeltoid, coriaceous, margin entire, upper margin with 2-4 shallow sinus; stalk 0.5-1.0 mm, persistent after pinna fall; veins 7-10, flabellate at base, each again 2-4 forked, visible on both surfaces. Sori2-4 per pinna, reniform.

Specimens examined: Lang Son Prov., Trang Dinh, That Khe cave, ca.260 m, grows in the crevices of rock walls, Chen Qiuyun, 4 Nov.2023, Chen 20231114001 (GXFI) ；Phan Ke Loc, 2009, 6046 (01870366) (PE) .

Distribution: Type specimens were collected and distributed in Guangxi, China. It grows in rock crevices. Newly recorded species for Vietnam.

Notes: This species is similar to Adiantum juxtapositum, and was initially identified as A. juxtapositum, such as Phan Ke Loc, 2009, 6046 (01870366) (PE) had been identified as A. juxtapositum and recorded in the book (Wei et al., 2022) , but it should be misidentified as A. longzhouensis. A. longzhouensis was formally published in 2017 and differs from A. juxtapositum in that it grows in limestone areas, pinna without white powder on abaxial surface, sori reniform.

Lepisorus bicolor Ching in Bull. Fan Mem. Inst. Biol.4（3）: 66.1933; Lin Youxing in Fl. Reipubl. Popularis Sin.6（3）: 35.2004; Qi Xinping et Zhang Xianchun in Flora of China Vol.2-3: 22.2013. —— Polypodium excavatum Bory ex Willd.var. bicolor Takeda in Notes Roy. Bot. Gard. Edinburgh 8（39）: 280.1915. 二色瓦韦（Fig.1: G-I）

Type: China. HenryA13070 (Holotype, E!) .

Plants 20-40 cm tall. Rhizomes creeping, strong, densely attached to scales that fall off easily. Scales closely appressed, bicolored, nearly black with much paler brown margins, broadly ovate-lanceolate, apex acuminate. Lamina lanceolate, widest 1/3-1/2 from base, both ends attenuate, herbaceous or thinly papery. Sori usually along distal half of lamina, or near end of lamina, closer to costa, elliptic or suborbicular; paraphyses black, suborbicular, membranous, margins erose; central lamina large and transparent, with marginal lamina irregular, cell walls brown, thickened.

Specimens examined：Lao Cai Prov., Sa Pa, Fansipan Mountain, ca.1 700 m, epiphyte in evergreen seasonal tropical broad-leaved, Chen Qiuyun, 12 Nov.2023, Chen 20231112003 (GXFI) .

Distribution: Type specimens were collected from Yunnan, China. It is distributed in Sichuan, Guizhou, Yunnan, Xizang and other places in China. The species is also found in India and Nepal. It grows on rocks, crevices or trunks. Newly recorded species for Vietnam.

Notes：The most obvious characteristics of the species are the scales on the rhizomes obviously dichroic, that is, the middle is nearly black and the edge is light brown, which are closely attached to the rhizomes and easy to fall off, and its leaves herbaceous and lanceolate.

Adiantum longzhouensis was found in limestone areas of Guangxi along the China-Vietnam border. Phlegmariurus guangdongensis was distributed in evergreen broad-leaved forests in Guangdong, Hainan, and Guangxi. Lepisorus bicolor was found in high-altitude areas of Yunnan and Sichuan, etc. These species were found in Vietnam, indicating the similarity of plant diversity between China and Vietnam. This contributes to a better understanding and deepening of biodiversity, helps assess the biodiversity status of a region, enhances our understanding of species distribution, evolutionary relationships, and their roles within ecosystems. It also promotes exchanges and cooperation between the two countries in the field of biodiversity conservation.

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