Aspidistra clausa N.Vislobokov, 2015

Vislobokov, Nikolay A., 2015, Two new species of Aspidistra (Asparagaceae, Nolinoideae) from northern Vietnam: A. clausa and A. triradiata, Phytotaxa 207 (3), pp. 265-272 : 266-268

Aspidistra clausa N.Vislobokov sp. nov. ( Fig. 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.

Figures

FIGURE 1. Aspidistra clausa. a, d. flowers, top view; b. longitudinal section of flower, style cross-dissected; c. longitudinal section of flower; e, f. flowering plant; g. flower, side view; h. flower, view from below; j. rhizome with fruit. (Images b, d, e provided by Olivier Colin).