Selaginella tenuifolia Spring, 1850

Shalimov, Aleksandr Petrovich, Wu, Yu-Dong & Zhang, Xian-Chun, 2019, A taxonomic revision of the genus Selaginella (Selaginellaceae) from Nepal, PhytoKeys 133, pp. 1-76 : 1

Selaginella tenuifolia Spring Figs 8 (3 A–C), 11D , 35

Selaginella tenuifolia Spring, Mém. Bull. Acad. Roy. Sci. Belgique 24(2): 253, n. 192. 1850; Alston 1945; Iwatsuki 1975; Iwatsuki 1988; Dixit 1992; Thapa 2002; Singh and Panigrahi 2005; Fraser-Jenkins et al. 2015; Fraser-Jenkins et al. 2017; Zhang 2018. Type. "Mishmi Hills, Griffith " (syntype: K), INDIA. Khasi Hills (cited by Spring as “Gorval” in error), Griffith (syntype: K).

= Selaginella aureola Spring, Mém. Acad. Sci. Brux. 24: 244. no. 182. 1850; Alston 1945. Type. (lectotype, designated by Fraser-Jenkins et al. 2015) INDIA. Churra-Punjee, Khasya, [W.] Griffith (182), [in 1835], Herbarium Hookerianum 1867 (K).

Description.

Stems 10-20 cm, erect. Rhizophores restricted to lower one-third part of main stems, very slender, long, 0.9-1.3 mm in diam. in lower part, lateral branches forked a few times. Stem slender, glabrous, stramineous, pinnately branched. Axillary leaves ovate or slightly ovate-lanceolate, 2.5-3.5 × 1.5-2.0 mm, margin denticulate in basal part, apex acute. Ventral leaves ovate, 3.5-4.5 × 2.0-2.8 mm oblique, in base cordate, acroscopic base endlanged, broadly overlapping stem and branches, margin denticulate, basiscopic base rounded, margin entire, apex sub-obtuse. Dorsal leaves ovate, 1.4-2.0 × 1.0-1.5 mm, oblique, in base subrounded, margin minutely dentate, apex aristate. Strobili solitary, terminal, compact, 4-8 × 1-2.5 mm. Sporophylls dimorphic, dorsal sporophylls ovate-oblong, spreading, in basal part slightly longer than apical, margin denticulate; ventral sporophylls ovate, with round base, margin denticulate, apex aristate. Megaspores brownish, surface verrucate; microspores yellowish-brown, surface irregularly verrucate.

Ecology.

Terrestrial or epilithic, seasonally green, scattered in moist shady places or clayey soils in forest. Alt. 700-2200 m.

Distribution in Nepal.

C, E.

Nepalese threatened status: NT ( Fraser-Jenkins et al. 2015).

General distribution.

CHINA (Xizang), INDIA (Assam State, Meghalaya, Sikkim, West Bengal), MYANMAR, THAILAND.

Chromosome number.

Not available data.

Selected specimens examined:

C Nepal: DOLAKHA: "Jiri, Dolakha, alt. 2000-2500 m, 3 Oct 1988, T. Nakaike 3065 " (PE); "Jiri, Dolakha, alt. 2000-2500 m, 3 Oct 1988, T. Nakaike 3061 " (PE).

MAKAWANPUR: "above Liot village, Basmari, c. 5 km W of Hetauda, off Narayanghat road. Densely sal-forested and rocky stream-gully on slope of first range of foothills beyond (N of) the Churiya Ghats. On rocks in forest, 24 Sep 1997, C.R. Fraser-Jenkins et al. 25756 (FN 1734) " (US, photo).

E Nepal: TAPLEJUNG: "Bhandukay-Yamphodin-Ghatte, 16 Nov 1963, H. Hara et al." (TI, photo); "Khebang-below Siling Tzokupa, 20 Nov 1963, H. Hara et al." (KUN, TI photo).

Note.

As reported by Fraser-Jenkins et al. (2015), S. tenuifolia is a rather uncommon low to mid altitude species, and widespread from Himalaya to Thailand. In our study (data not published) two collections were included, one from Nepal (T. Nakaike 3065), and another from SW Xizang (PE-Xizang Expedition PT6280). Examined samples were studied on three grounds: gross morphology, morphology of spores and molecular data. Results of gross morphology did not show big differentiation in morphology features for examined samples (incl. observation of ventral and dorsal leaves, shape of leaf margin, strobili, ventral and dorsal sporophylls. Ventral leaves broadly overlapping stem and branches, margin denticulate; Dorsal leaves: ovate, at apex aristate, margin denticulate. Strobili oval in shape; ventral and dorsal sporophylls at margin denticulate.

In both examined collections megaspores on the proximal and distal surfaces are covered with irregularly sized verrucae, the main surface is vermiculate, micro-sculptures are dense spinulose. Microspores on the proximal and distal surfaces are covered with irregularly sized verrucae, micro-sculptures are echinulate.

The molecular data also support the results of morphological studies.

As a result, we consider the distribution of the species not only at low and medium altitudes but also in the highlands.

Figures

Figure 8. Morphological diversity of the leaves of Nepalese Sealginella species 1 A-C S. reticulata (Nakaike 1760, PE) 2 A-C S. subdiaphana (Zhang 5, PE) 3 A-C S. tenuifolia (PE-Xizang Exped. PE 6280, PE). A - Axillary leaves, B - Dorsal leaves, C - Ventral leaves. Scale bars: 0.2 mm.

Figure 11. Diversity strobili of Nepalese Selaginella species A S. chrysorrhizos (Nakaike 3708, PE) B S. reticulata (Nakaike 1760, PE) C S. subdiaphana (Zhang 5, PE) D S. tenuifolia (PE-Xizang Exped. PE 6280, PE). Scale bars: 1 mm (A, D), 2 mm (B, C).

Figure 35. Selaginella tenuifolia Spring A (A 1, A 2) Habit, upper surface (J. H. Lance s. n., E) B Strobilus, lower surface C Fragment of the upper surface of the lateral branches (A (A 1, A 2) J. H. Lace s. n., E; B, C PE-Xizang Expedition PE 6280, PE) Link: (http: // data. rbge. org. uk / herb / E 00800185).