Tupistra breviscapa 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 : 43-44

Tupistra breviscapa Aver. & N.Tanaka , sp. nov.

( Figs 11 ; 12 )

Haec species nova Tupistrae theanae Aver. & N.Tanaka affinis est, sed ab ea pedunculo multo breviore, floribus in quoque scapo paucioribus, bracteis exterioribus floris flores excendentibus, et stigmata minore et tripartitis bene differt.

TYPUS. — Laos. Khammouane province, Thakhek district, environs of Thakhek town around point 17°27.195’N, 104°57.790’E, dry secondary evergreen broad-leaved forest on marble-like limestone at elevation about 161 m a.s.l., lithophytic rosulate herb in crevices of vertical shady cliffs, leaves rigid, up to 1.4 m long, 3.XI.2013 , E.Konstantinov K248 (holo-, LE!; iso-, LE!) .

ETYMOLOGY. — The specific epithet refers to the short scape (or sexually reproductive stem) of the species.

HABITAT AND PHENOLOGY. — Primary and secondary dry evergreen broad-leaved forests on eroded marble-like crystalline limestone at elevations 150-200 m a.s.l. Obligate lithophyte on shady vertical limestone cliffs. Flowers in September-October. Rare. Expected IUCN Red List status – DD.

DISTRIBUTION. — Laos (Khammouane province, Thakhek district). Local endemic of southern Laos.

AFFINITIES

This new species is allied to Tupistra theana Aver.& N.Tanaka , but differs from it by the much shorter peduncle, fewer flowers per scape, outer floral bracts exceeding the flowers, and the smaller tripartite stigma.

DESCRIPTION

Lithophytic perennial herb. Rhizome erect or suberect, simple or a few branched, terete, stout, slightly woody, dark browngray to almost black, 5-10(15) cm long, (1.2)1.5-2(2.2) cm in diam. Roots cord-like, thick, fleshy, covered densely with black root hairs in most part. Stem erect, very short, 1-1.5 cm tall, covered with dilated leaf bases and fibrous remnants of decaying sheath leaves (cataphylls). Sheath leaves straight or slightly recurved, ensiform, conduplicate, green, (3.5)5-15(20) cm long, (0.4)0.6-1(1.4) cm wide, fugacious, becoming soon drying, papyraceous and dull yellowish-brown. Leaves basal, (2)3-5(6), suberect to arcuate, sub-sessile, equitant, indistinctly petiolate, oblanceolate, (0.7)0.9-1.3(1.5) m long, (3.5)4-5(6) cm wide, gradually tapering to rigid, canaliculate, petiole-like base, acute at apex, rigid, leathery, uniformly green, glossy, midvein prominent abaxially. Peduncle arising from top of stem, axillary, erect, straight, rigid, 4-6(8) cm long, (1.5) 2- 3 mm in diam., naked, fleshy, white to light green, becoming slightly thicker upward. Inflorescence a simple, loose, terminal spadix-like spike of several flowers, 2.5-3(4.5) cm long, 1.2- 1.5 cm in diam.; rachis several-angled longitudinally, fleshy, slightly raised around flower pits. Floral bracts 2 per flower, triangular, conduplicate toward base, spreading, becoming drying, papyraceous, dull yellowish-brown to dark brown; outer bract located below flower, acute to acuminate, finely serrulate distally, (6)8-12(14) mm long, (5)6-8(9) mm wide, exceeding the flower; inner bract (bracteole) lying lateral to flower, acute, oblique, (3.5)4-6(7) mm long, 1.5-2(2.5) mm wide. Flowers several, sessile, campanulate or suburceolate, not fully open, 6-8 mm across; perianth (7)8-9(10) mm long, 6-cleft distally, cup or bowl-shaped in proximal half, dark dirty purple, fleshy; segments triangular-ovate, obtuse and often irregularly serrulate apically, 4.5-5 mm long and wide. Stamens 6, opposite to perianth segments; anthers inserted at perianth tube close to base of segments, ellipsoid, introrse, slightly incurved, 1.5-1.8(2) mm long, light dull yellow, dorsifixed on short fleshy filaments 0.5 mm long. Ovaryexternally very indistinct, 3-loculed, each locule with 1 lens-shaped ovule on an axial placenta; style columnar, slightly broadened toward the base, truncate at apex, 3-ridged longitudinally, yellowishpink, 4 mm tall, 1-1.5 mm in diam., not exceeding the base of anthers; stigma 3-partite, 1-1.2 mm in diam., almost dull yellowish-brown, lobes rectangular, convex,ventrally grooved longitudinally, densely papillulate. Fruits unknown.

REMARKS

Tupistra breviscapa Aver. & N.Tanaka , sp. nov. is most closely allied to T. theana Aver. & N.Tanaka from central Vietnam ( Averyanov & Tanaka 2012) in having a similar floral shape, similar coloration of perianth and style, and a relatively small pistil. It differs, however, by the much shorter peduncle (vs peduncle over 20 cm), fewer flowers per scape, outer floral bracts exceeding the flowers (vs bracts as long as the flowers), and the smaller tripartite stigma nearly as broad as the style (vs indistinctly 3-lobed or nearly entire stigma significantly broader than the style).

The new species appears close to the genus Rohdea ( Roth 1821; Tanaka 2003a, 2010a) in having a relatively small tripartite stigma, but is assignable to Tupistra ( Ker Gawler 1814; Tanaka 2003b, 2010b) by the leaf with a more slender petiole-like base, purplish perianth (vs greenish perianth), and the stout style nearly as thick as the ovary. Of the species of Tupistra hitherto known, the new species seems to retain the most primitive character state especially as to pistil. In this respect, it may be more primitive than T. theana .

Figures

FIG. 11. — Tupistra breviscapa Aver. & N.Tanaka, sp. nov.: A, flowering plant; B, inflorescence on peduncle; C, inflorescence, 2 flowers in front removed; D, por- tion of inflorescence with outer floral bracts and inner bracteoles, flowers removed; E, floral bracts and bracteoles from basal and apical part of inflorescence; F, flowers in different side views; G, flowers, upper and frontal views; H, interior of perianth with stamens, cut and flattened; I, pistils in different side views; J, pistil, frontal view; K, transversal section of ovary.All drawn by L.Averyanov and T.Maisak from the type E. Konstantinov K248.Scale bars: A,50 cm; B, C, 1 cm; D-H, 5 mm; I, 2 mm; J, K, 1 mm.

FIG. 12. — Tupistra breviscapa Aver. & N.Tanaka, sp. nov.: A, plants in natural habitat; B, flowering plant; C, inflorescence on peduncle; D, inflorescence rachis with flowers. All photos from the type specimen E.Konstantinov K248 by E.Konstantinov, image correction and design by L.Averyanov. Scale bars: B, 10 cm; C,5 cm; D, 1 cm.