Herminium hongdeyuanii B. B. Raskoti, 2013

Raskoti, Bhakta Bahadur, 2013, A new species of Herminium (Orchidoideae, Orchidaceae) from Nepal, Phytotaxa 98 (1), pp. 23-26 : 23-26

Herminium hongdeyuanii B. B. Raskoti , sp. nov. Figs. 1 & 2 .

Type: — NEPAL. Chandragiri , 2200 m, 25 September 2012, Raskoti 571 (holotype KATH!) .

This new species is close to the Herminium lanceum (Thunberg ex Swartz, 1800: 223) Vuijk (1961: 228) , but it differs in having smaller flowers with a winged peduncle, the midlobe of the lip is longer than the lateral lobes, the lateral lobes are triangular but always wider than the midlobe and it has an ovoid viscidium.

Plants 35–42 cm tall. Tubers subglobose, 10 × 5 mm. Stem with 2 tubular sheaths at base, upper part with 3 leaves. Leaves cauline, alternate, linear, 15–21 cm long, 0.5–1.0 cm in wide, apex acuminate, base sheathing. Inflorescence 20 cm; peduncle 4–6 cm, ridged, without sterile bracts; rachis 13–15 cm, with several secund flowers; floral bracts lanceolate, 5–10 × 1–2 mm, 1-veined, exceeding or shorter than the ovary, apex acuminate. Flowers yellowish green, 2–3 mm across, secund, ovary fusiform, slightly arcuate, 5–9 mm long, ridged, apex slightly beaked; dorsal sepal suberect, ovate, 2 × 1 mm, indistinctly 1-veined, apex sub-obtuse; lateral sepals spreading, ovate, oblique, 2.5 × 1.0 mm, apex sub-obtuse; petals forming a hood with dorsal sepal, oblong, 2.0–4.0 × 1.0 mm, 1-veined, apex obtuse, lip oblong, held horizontally, slightly curved, 1.0–3.0 × 0.5–1.0 mm, base dilated shallowly concave, contracted in the middle, with three ridges running from base to the midlobe, trilobed near apex; lateral lobes falcately triangular, 0.5 × 0.5 mm, apex sub-obtuse; midlobe triangular, 0.7 × 0.4 mm, apex sub-obtuse. Column ca. 1 mm; auricle ca. 0.5 mm, pollinia 0.5 mm, globose; viscidia ovoid, stigma transverse, ca. 1 mm, extending outwards from the rostellum.

Flowering time: ⎯September

Distribution: ⎯Known from only the type locality in central Nepal.

Habit and ecology: ⎯Terrestrial in humus-rich grasslands on moist slopes, also in partial shade in temperate forest, 2200 m elevation.

Etymology: ⎯The species is named for Prof. Dr. HONG De-Yuan in honor of his outstanding contributions to plant sciences.

Notes: ⎯ Herminium hongdeyuanii is similar to Herminium lanceum (Thunb. ex Sw.) Vuijk and shares with it floral characters such as an ovate dorsal sepal, obliquely ovate lateral sepals, and petals that form a hood with the dorsal sepal ( King & Pantling 1898, Pearce & Cribb 2002, Chen et al. 2009). However, H. hongdeyuanii differs from H. lanceum in having smaller flowers, winged peduncle, midlobe of the lip longer than lateral lobes, triangular lateral lobes that are wider than the midlobe and an ovoid viscidium. Although, H. lanceum has a cylindric peduncle, its flower is larger, lateral lobes of lip are linear-filiform and always longer than the midlobe and its viscidium is orbicular. Herminium lanceum has variation in lip shape and dimensions, but its lateral lobes are always longer than the midlobe and linear-filiform ( Banerji & Pradhan 1984, Pearce & Cribb 2002, Chen et al. 2009, Pedersen et al. 2011). Similarly H. hongdeyuanii has some similarity to Herminium souliei ( Finet, 1901: 518) Rolfe (1903: 51) in its lip, such as a dilated and shallowly concave base, but the midlobe of H. souliei is always shorter than the lateral lobes.

Another species, Herminium coiloglossum Schlechter (1906: 15) is similar to H. hongdeyuanii in its ovate dorsal sepal, falcate, triangular lateral lobes of the lip and ovoid viscidia, but it differs in having a single basal leaf, cylindric peduncle, sterile bracts, floral bracts always shorter than the ovary, ovary and pedicel short, lateral sepals oblong-ovate, petals oblique and midlobe wider than the lateral lobes. Likewise Herminium quinquelobum King & Pantling (1896:130) is similar to H. hongdeyuanii in having triangular lateral lip lobes, but it clearly differs in having a five-lobed lip.

Figures

FIGURE 1. Herminium hongdeyuanii A. Flowering plant. B. Flower (side view). C. Dorsal sepal. D. Lateral sepal. E. Petal. F. Lip. G. Column. H. Pollinia. (All drawn from type by the author.)

FIGURE 2. Herminium hongdeyuanii A. Flowering plant. B. Flower (side view). C. Dorsal sepal. D. Lateral sepal. E. Petal. F. Lip. G. Column. H. Pollinia. (All photographs from type by the author.)