Ophiopogon petraeus Aver. & N.Tanaka, 2015

Averyanov, Leonid V., Tanaka, Noriyuki, Nguyen, Khang Sinh, Nguyen, Hiep Tien & Konstantinov, Eugene L., 2015, New species of Ophiopogon Ker Gawl., Peliosanthes Andrews and Tupistra Ker Gawl. (Asparagaceae) in the flora of Laos and Vietnam, Adansonia 37 (1), pp. 25-45 : 30-32

Ophiopogon petraeus Aver. & N.Tanaka , sp. nov.

( Fig. 4 )

Haec species Ophiopogoni platyphyllo Merr. & Chun subsimilis est, sed ab eo pedicellis plerumque longioribus, segmentis perianthii ovatis brevioribusque, antheris brevioribus, et stylo basi paulo inflato bene differt.

TYPUS. — Vietnam. Lang Son province, Huu Lung district, Huu Lien commune, Huu Lien Nature Reserve , around point 21°40’28”N, 106°22’34”E ”, flowered and collected under cultivation in Septem- ber– October 2013, leaves fleshy, at the base subsucculent, juicy, transversely oval in section, flowers white, anthers light yellow-green, pedicel white with violet tint , L. Averyanov , HAL 11220b/1 (holo-, LE!).

EPITYPUS. — Vietnam. d-EXSICCATES OF VIETNAMESE FLORA 0207/HAL 11220b/1 ( Fig. 4 ).

ETYMOLOGY. — The specific epithet refers to the stony habit of the species.

HABITAT AND PHENOLOGY. — Lithophytic or terrestrial herb on shady rocky limestone outcrops in primary seasonal lowland forests of mixed and broad-leaved evergreen trees at elevations 400-600 m a.s.l. Flowers under cultivation in September-October. Not rare. Expected IUCN Red List status – LC.

DISTRIBUTION. — Vietnam (Lang Son province, Huu Lung district, territory of Huu Lien nature reserve). Endemic of limestone areas of northern Vietnam.

MATERIAL EXAMINED (PARATYPI). — Vietnam. Lang Son province, Huu Lung district., Huu Lien commune, Huu Lien Nature Reserve , around point 21°40’28”N, 106°22’34”E, primary closed evergreen seasonal tropical mixed forests on rocky limestone at elevations 400- 600 m, lithophytic rosulate herb, not rare, 24.IX.2007, P. K . Loc , N. T . Vinh , H. V . Luat , HAL 11220 b ( HN?).

AFFINITIES

This species somewhat resembles Ophiopogon platyphyllus Merr. & Chun , but markedly differs from it in the usually longer pedicels, shorter ovate perianth segments, shorter anthers, and in the style slightly inflated at the base.

DESCRIPTION

Lithophytic or occasionally terrestrial, perennial herb from short semi-epigeous rhizome; stems short, erect, normally unbranching, (2) 3-5 cm tall, 1-1.5 cm in diam., covered imbricately with narrowly ovate, papyraceous, dull brownish sheath leaves(2) 3-7 cm long, bearing a few, rigid, semi-woody roots 3-4 mm in diam. at base. Leaves (6)8-12(14), tufted at apex of stem, subdistichous, arching, indistinctly petiolate, linear-oblanceolate, often slightly oblique, gradually narrowed into petiole-like basal partbeing succulent and transversely oval in cross section, obtuse at apex, entire along margins, fleshy, coriaceous, glabrous, (16)25-35(40) cm long, (1)1.8-2(2.2) cm wide; adaxially glossy, uniformly dark grass-green; abaxially light green-glaucous, with many parallel narrow white stripes; main longitudinal veins indistinct, numerous; secondary veins hardly visible. Inflorescence a lax raceme with distant fascicles of (2)3-4(5) pedicellate flowers; rachis straight, finely ridged, dull greenish to white, 10-15 cm long; the pedicels arising from bracteal axils, sub-perpendicular to rachis, straight or slightly arching, terete,light violet to white, (6)8-14(16) mm long, 0.8-1 mm in diam., terminally jointed to flower base with distinct articulation; in each fascicle, the outermost basal bract narrowly triangular, acute or acuminate, scarious, light greenish or yellowish white, often with violet tint, (2)3-7(8) mm long, 1.5-4 mm wide; the inner bracteoles subtending each pedicel triangular,whitish, scarious, 0.5-1.5 mm long and wide; peduncle ebracteate or with 1-2 small sterile, scarious bracts being light olive-green with light violet tint, straight, 10-15 cm long, 3-4 mm in diam. Flowers slightly drooping, campanulate, not much broadly expanding, white, odorless, 4-4.5 mm long, (8)9-10(11) mm across. Perianth segments subsimilar, ovate, blunt to rounded at apex, distally slightly recurved, flat or slightly revolute along margins, thick, 4.5- 5 mm long, 3-3.5 mm wide. Stamens 6, located at base of each perianth segment, connivent distally; anthers narrowly subconic, slightly complanate, cordate at base, acute at apex, introrse, light greenish, 2 mm long, 0.5-0.6 mm wide; filaments massively thick and wide, 0.4-0.6 mm long and wide. Ovary inferior, 3-locular; each locule containing 2 ovules on a basal placenta; style erect, straight, narrowly pyramidal, 4-4.5 mm long, basal part somewhat inflated, 1-1.2 mm wide, white; stigma almost negligibly minute.

REMARKS

The obtuse, linear-oblanceolate leaves of Ophiopogon petraeus Aver. & N.Tanaka , sp. nov. somewhat resemble those of O. platyphyllus Merr. & Chun ( Merrill & Chun 1935; Tanaka 2000a). However, the new species differs in the usually longer pedicels, shorter ovate perianth segments (vs lanceolate), shorter anthers, and the style slightly inflated at the base (vs style not particularly inflated basally). It also somewhat resembles O. pseudotonkinensis D.Fang ( Fang 1998) , but is distinguishable in having coriaceous leaves (vs chartaceous leaves) and shorter free anthers.

Figures

FIG. 4. — Ophiopogon petraeus Aver.& N.Tanaka, sp. nov., digital epitype “d-EXSICCATES OF VIETNAMESE FLORA 0207/HAL 1122ob (LE)”: A, flowering plant; B, cataphylls; C, portions of inflorescence with flower buds and open flowers; D, base of plant; E, leaves and cataphylls; F, flower buds in bract axill; G, H, intact flowers, flowers with 3 tepals removed and sagittal section of flowers; I, flowers buds with pedicels; J, anthers; K, sepals and petals; L, abaxial and adaxial surface of leaf; M, sagittal section of pistil and ovary. Photos by L.Averyanov. Scale bars: A, B, E, 5 cm; G, H, I, 1 cm; J, 2 mm; K, 5 mm.