Aspidistra clausa N.Vislobokov, 2015

Aspidistra clausa N.Vislobokov View in CoL sp. nov. ( Fig. 1 View FIGURE 1 )

Similar to A. crassifila , but leaves narrower (lamina 2.8–4.5 cm vs. 6–12 cm), perigone tube wide tubular vs. campanulate, appendages longer, stigma conical vs. mushroom-shaped.

Type:— VIETNAM, Vinh Phuc province, Tam Dao district, Tam Dao National Park, about 3 km NW from Tam Dao City. 21° 28,405’ N, 105˚ 38,351’ E, alt. 978 m, rainforest, 19 November 2014, N. A. Vislobokov 14097 ( holotype MW!, including reproductive organs in liquid collection at Moscow University).

Herbaceous perennial, rhizomatous, evergreen plant. Rhizome creeping, with very short internodes, epigeous, Ø 5.4 –7 [6.4] mm. Roots grey, Ø 1.1 –1.4 [1.3] mm, with 1–2-layered velamen, root hairs deciduous, endoderm 1– 2-layered, pericycle of cells with lignified walls. Rhizomes with regularly repeating units, each comprising ca. 4 distichously arranged cataphylls followed by a foliage leaf. Cataphylls oblong, up to 9 cm long, promptly withering and disintegrating. Foliage leaves distinctly divided into petiole and lamina. Petiole green, adaxially sulcate, 15–32 [23.8] cm long, Ø 2.2 –3.2 [2.7] mm. Lamina light green, oblong, basally cuneate and distally acuminate, 26–41 [35.8] cm long, 2.8–4.5 [3.6] cm wide. The midvein somewhat prominent at lower surface. Peduncle (specialized reproductive shoot) white, purple spotted, 2.8–4.6 [3.7] cm long, Ø 2.4 –2.8 [2.5] mm, with 5–7 purple mottled, widely ovate, acuminate, 11.8–13.4 [12.7] mm long, 8.9 mm wide distichously arranged scale leaves. Flower solitary at the end of peduncle. Perigone 18–18.3 [18.2] mm long, Ø 38.7 –42.5 [40.5] mm; tube white with purple spots outside, purple inside, widely tubular, 12.9–14.6 [13.3] mm long, Ø 14.6 –15.1 [14.8] mm; lobes 8, purple mottled to completely purple at both sides, triangular-lanceolate, with appendages at the base; appendages purple, protruding to mouth of perigone tube, fimbriate, 2.1–2.8 [2.5] mm long. Stamens 8 (in the same number as perigone lobes), inserted at the middle of the perigone tube lower than stigma, at the radii of tepals; filaments with purple spots, cylindrical, 4 mm long, Ø 1.3 –1.5 [1.4] mm, anthers 2.4–2.5 [2.5] mm long, 1.4–1.8 [1.6] mm wide, introrse, pollen sacs positioned at lower side of connectives, connectives white. Pistil 11.7 mm high. Style white with purple spots, cylindrical, 4.8 mm long, Ø 2.9 mm. Stigma white with purple spots at lower surface, purple with four white radial bifurcated crests at upper surface, highly convex (conical) at center, 7 mm high, Ø 7–7.7 [7.4] mm, 4-lobed at margin, lobes emarginated at apex. Ovary inconspicuous, superior, 4-locular. Fruits grayish black, subspherical, 13–15.6 [14.7] mm long, Ø 14–16.6 [15.3] mm, with short protuberances. A carpophore is absent.

Molecular description: — Differences found in alignments of all currently available accessions of Aspidistra of investigated sequences of psb A- trn H and 5S-NTS regions are summarised in Tables 1–2. In psb A- trn H region ( Table 1), the new species A. clausa is similar to A. triradiata and Aspidistra sp. 1 , an unidentified species (see Vislobokov et al. 2014b). It seems that possibility of using psb A- trn H region for molecular barcoding within Aspidistra is limited. In 5S-NTS region, the most remarkable feature of the new species is a 9 bp deletion between nucleotides 188 and 119 (direct nucleotide positions; these are equivalent to positions 201–209 in the alignment, Table 2) within indel 8, which is common for A. clausa , A. triradiata , and A. xuansonensis Vislobokov in Vislobokov et al. (2014c: 227) (a species from northern Vietnam vs. other accessions from southern Vietnam). In addition, there are a few unique features distinguish 5S-NTS sequences of the new species from other accessions: Thymine not Guanine at direct nucleotide position 8 (within indel 1); Guanine not Adenine at direct nucleotide position 38; Cytosine not Guanine at direct nucleotide position 271; Guanine not Adenine at direct nucleotide position 303.

Etymology: — The specific epithet “ clausa ” means “closed”, it explains the structure of flowers where stamens are hidden by tepal appendages. In flowers of the similar species A. crassifila Liu & Peng in Lin et al. (2013: 43) stamens are visible from above between adaxial surface of perigone tube and margin of stigma.

Distribution: — The species is known only from the type locality.

Taxonomic relationships:—The new species resembles and probably closely relates to A. crassifila but differs in width of leaf blade ( 2.8–4.5 cm vs. 6–12 cm), perigone tube wide tubular vs. campanulate, appendages longer, filaments and connectives white with purple spots vs. completely purple, stigma conical vs. mushroom-shaped. Also flowers of A. clausa are somewhat similar to flowers of A. patentiloba Wan & Lu (1989: 99) , but strongly differ in stigma shape and should not be considered as closely related species.