Selaginella densiciliata X.M.Zhou, Liang Zhang & Bo Xu, 2023

Fang, Shao-Li, Xu, Bo, Zhang, Liang, He, Zhao-Rong & Zhou, Xin-Mao, 2023, Selaginella densiciliata (subg. Heterostachys, Selaginellaceae), a new spikemoss species from China based on morphological and molecular data, PhytoKeys 227, pp. 135-149 : 135

publication ID

https://dx.doi.org/10.3897/phytokeys.227.101222

persistent identifier

https://treatment.plazi.org/id/B2761967-8FDB-5D36-BA91-5DC6E1EE8106

treatment provided by

PhytoKeys by Pensoft

scientific name

Selaginella densiciliata X.M.Zhou, Liang Zhang & Bo Xu
status

sp. nov.

Selaginella densiciliata X.M.Zhou, Liang Zhang & Bo Xu sp. nov.

Type.

China. Xizang: Medog County, Beibeng Township , on the way from A’niqiao to #3 bridge, in broad-leaved evergreen forest, 29°20'41.56"N, 95°9'56.99"E, elev. 1600 m, 15 Oct. 2017, Liang Zhang, Wen-Bin Ju & Heng-Ning Deng 2215 (holotype: KUN-1572683!, isotypes: KUN-1572684!, PYU-02074721!, PYU-02074722!) GoogleMaps .

Diagnosis.

Selaginella densiciliata is similar to S. repanda , S. subvaginata , and S. vaginata in having relatively small plants (Fig. 3E View Figure 3 ), base of stem with ventral leaves strongly curly and surrounding stem when dry (Fig. 3E View Figure 3 ), submonomorphic sporophylls (Fig. 2B, F, G View Figure 2 ), but the new species has sterile leaves margins densely ciliate at base (Fig. 2H-J View Figure 2 ), dorsal leaves obviously carinate (Fig. 2D, I View Figure 2 ), symmetrical axillary leaves oblong-ovate ovate-triangular (Fig. 2H View Figure 2 ), and megaspore surfaces fine reticulate (Fig. 2M, N View Figure 2 ).

Description.

Plants terrestrial, evergreen, ascending to suberect, 7.0-15.0 cm tall, without creeping rhizomes or stolons, without elongate tuber at base of stem (Fig. 3E View Figure 3 ). Rhizophores grow from the base to the middle of stem, borne on ventral side in axils of branches (Figs 2C View Figure 2 , 3E View Figure 3 ), 0.2-0.3 mm in diam. Main stem branched upwards from near the base, pinnately branched (Figs 2A View Figure 2 , 3 View Figure 3 ), unbranched main stem is 0.5-3.5 cm tall, terete, glabrous, 0.4-0.6 mm in diam (Fig. 3 View Figure 3 ). Branches 6-14 pairs, 2 or 3 times pinnately branched; adjacent main branches on main stem 3.1-5.0 mm apart, the terminal branches 2.6-5.2 mm wide (Fig. 3C-E View Figure 3 ). Sterile leaves four rows, leathery, margins densely ciliate on the lower parts or at least at base (Fig. 2H-J View Figure 2 ). Axillary leaves on main stems not larger than those on branches, symmetrical, oblong-ovate to ovate-triangular ovate-triangular, base not peltate, truncate; axillary leaves on branches symmetrical, oblong-ovate to ovate-triangular, base cordate, 1.6-2.1 × 0.8-1.2 mm, slightly carinate, margins densely ciliate in basal half to denticulate at apex, apex acute (Fig. 2C, E, H View Figure 2 ). Dorsal leaves asymmetrical, those on main stems strongly larger than those on branches; ovate, 1.2-1.9 × 0.5-1.0 mm, strongly carinate, base truncate, oblique, peltate, margins slightly densely ciliate at basal half, upward denticulate, apex shortly aristate (Fig. 2C, E, J View Figure 2 ). Ventral leaves asymmetrical, overlapping stem and branches, those on main stem strongly larger than those on branches, oblong-falcate, 2.0-2.7 × 1.0-1.5 mm, carinate, base round, peltate, apex acute; basiscopic margins slightly denticulate at base, upward subentire; acroscopic base margins densely ciliate at lower part, upward subentire (Fig. 2D, I View Figure 2 ). Strobili solitary, terminal, compact, quadrangular, 4.3-7.9 mm (Figs 2B, F, G View Figure 2 , 3A, B View Figure 3 ). Sporophylls slightly dimorphic, dorsal sporophylls slightly longer than ventral sporophylls (Fig. 2B, F, G View Figure 2 ); dorsal sporophylls ovate, carinate, 1.4-1.5 × 0.7-0.9 mm, margins denticulate, base cuneate, not peltate, apex acuminate, without sporophyll-pteryx (Fig. 2K View Figure 2 ); ventral sporophylls broadly ovate, carinate, 1.23-1.47 × 0.69-0.81 mm, base truncate, not peltate, apex acuminate, margin denticulate (Fig. 2G View Figure 2 ). Megasporophylls in basal portion on lower side of strobilus. Megaspore white-yellow, oblate spheroid to subglobose, 225.6-280.2 μm in diam., prominent laesurae extend 2/3 of the distance to the equator; surface finely reticulate ornamentation (Fig. 2M, N View Figure 2 ). Microspore orange, hemispherical, 27.4-37.7 μm, surfaces with dense and large verrucate ornamentation covered with densely irregular granular microstructure (Fig. 2O, P View Figure 2 ).

Geographical distribution and habitat.

Selaginella densiciliata is only known from Beibeng Township, Medog County, Xizang Province, China. It grows in humid places in evergreen broadleaved forests, at elevations of 1000-1600 m.

Additional specimens examined (paratypes).

China. Xizang: Nyingchi City, Medog county, Beibeng township. on the way from A’niqiao to Hanmi village, elev. ca. 1000 m, 29°20'14.40"N, 95°10'19.19"E, 4 Jun. 2015. Bo Xu & Xin-Mao Zhou YLZB2043 (CDBI, PYU); on the way from A’niqiao to Hanmi village, elev. 1530 m, 29°20'29.51"N, 95°10'12.74"E, 15 Oct. 2017, Liang Zhang, Wen-Bin Ju & Heng-Ning Deng 2090 (KUN, PYU); on the way from A’niqiao to Hanmi village , alt. 1120 m, 29°19'42.75"N, 95°10'36.47"E, 17 Oct. 2017, Liang Zhang, Wen-Bin Ju & Heng-Ning Deng 2203 (KUN, PYU) GoogleMaps .

Etymology.

The specific epithet " Selaginella densiciliata " is a compound word derived from the Latin word " dense " which means dense and suffix " ciliata " which means ciliate. The specific epithet " Selaginella densiciliata " refers to sterile leave (axillary leaves, dorsal leaves, and ventral leaves, Fig. 2H-J View Figure 2 ) margins with dense cilia at base.