Peliosanthes subspicata N. Tanaka, 2018

Tanaka, Noriyuki, 2018, Taxonomic revision of Peliosanthes bakeri and P. violacea (Asparagaceae), with description of two new species from Bangladesh and India, Phytotaxa 356 (1), pp. 34-48 : 40-44

4. Peliosanthes subspicata N. Tanaka , sp. nov. ( Figs. 4–6 ).

Closely related to P. violacea , but differs by the shorter pedicels, smaller drooping flowers, minutely erose perigone segments, staminal corona abruptly raised at periphery of the central orifice, slightly larger anthers, style with 3 narrow intercarpellary (septal) wings, and larger stigma.

Type:― INDIA. Khasia, 0–4000 ft, November 1850, J.D. Hooker & T. Thomson s.n. (holotype K-000099349!–lectoparatype of P. violacea var. violacea , p.p., excluding the second rightmost, distally trifurcate scape).

Peliosanthes violacea Wallich ex Baker var. clarkei Baker (1879: 504) , p.p.

Peliosanthes violace a Wallich ex Baker var. minor Baker (1879: 504) , p.p.

Peliosanthes violacea Wallich ex Baker var. violacea Baker (1879: 504) , p.p.

Peliosanthes teta auct. non Andrews (1810, t. 605): Wallich (1831–1832 in 1828–1849, List. no. 5083A).

Peliosanthes violacea auct. non Wallich ex Baker: Hooker (1892: 266), p.p., as to “ P. teta in Wallich List no. 5083A” cited.

Herb acaulescent, evergreen, perennial. Rhizome subterete, to ca. 1 cm thick, knobby, often shortly branched and clumpy. Roots cordlike, to 2 mm in diam. Sheath leaves (cataphylls) several at base of foliar petiole, unequal in length, outer ones shorter, inner longer ones linear lanceolate or lanceolate, to 15 cm long, membranous along margins. Leaves usually 2–7, basal, tufted; petiole erect to suberect, 25–50 cm long, to 4 mm in diam. near base; blade narrowly elliptic or oblanceolate, 23–31 cm long, 4.5–7.3 cm wide, base cuneate, margins entire, apex acute or shortly acuminate; longitudinal veins usually 17–25; cross veinlets numerous, closely spaced, perpendicular or slightly oblique to longitudinal veins. Peduncle suberect or ascending, 6.5–13 cm long; sterile bracts on peduncle 6–10(–14) excluding those congested at base, antrorse, ovate or lanceolate, to 2.5 cm long, to 1 cm wide near base, scarious along margins, acute or acuminate. Inflorescence subspicate, many-flowered, 7.5–26 cm long, 0.8–1.3 cm in diam., rachis terete, 1.5–3 mm in diam. near base. Flowers 1 in axils of bracts, 3.5–9 mm in diam., drooping; pedicel 0.5–2.5 mm long, subtended at base by two bracts; the lower bract larger, narrowly triangular-lanceolate to subulate, 4.5–13 mm long, 1–2.5 mm wide, usually descending, the upper (bracteole) subulate, 2–3 mm long, ascending. Perigone broadly obconic or crateriform, 6-cleft, fleshy, pale yellowish green or green; proximal tubular part broadly obconic, 1.5–2 mm high (2–3 mm long); distal segments obliquely expanded, ovate, broadly ovate or suborbicular, 1.7–4 mm long, 2–4.5 mm wide, proximally imbricate, margins minutely (denticulate-)erose, apex rotund or obtuse. Stamens 6; filaments connate, forming corona orbicular at base, 3.5–4.5 mm in diam., proximally flat or slightly descending, distally abruptly raised at periphery of central orifice, forming annular ridge often recurved and truncate (entire) apically, reddish, orifice 1.5–2.5 mm in diam.; anthers sessile, dorsally attached to distal inner wall of coronal ridge, bilocular, introrse, ovoid, 0.7–1.5 mm long, recurved when dehisced, distal portion slightly exserted from corona. Pistil 1, tricarpous, distal free part subconic, 1.5–2 mm long; ovary half-inferior, triloculate; ovules to 5 per locule, borne at base of central axis of ovary, ellipsoid or obovoid; style subterete, slightly narrowing distally, 0.5–1 mm long, obtusely trigonous, longitudinally narrowly 3-winged along connate portions between carpels; stigma nearly as high as apex of anthers, trifid or triparted, 0.9–1 mm wide, lobes oblong-ovate, ca. 0.5 mm long, distally descending. Seeds ellipsoid or ovoid, to 15 mm long, 8–9 mm in diam.

Additional specimens examined (paratypes):― BANGLADESH. Silhet, W. Gomez 133, N. Wallich List no. 5083 A (K-001104683*). INDIA. East Bengal, 17 Octoer 1835, W. Griffith 5834 (K-000099367–lectoparatype of P. violacea var. minor , p.p., as to the left individual and two flowering scapes, the right individual without scape is P. griffithii ); East Bengal, W. Griffith 5838 (K-000099369–lectoparatype of P. violacea var. minor , p.p, as to the left individual, the right one is P. griffithii ; L-1449932*–isolectoparatype of P. violacea var. minor ); Khasia. T. Lobb s.n. (K-000099350–lectoparatype of P. violacea var. violacea ; for the locality see the “notes” below); Mont. Khasia, elev. 0–4000 ft., J.D. Hooker & T. Thomson s.n. (P-00214606–isolectoparatype of P. violacea var. clarkei , p.p., the right individual only, the left one is P. violacea var. clarkei ); Cachar, 9 October 1873, R. L. Keenan s.n. (K-000099345– lectoparatype of P. violacea var. violacea ). PROVENANCE UNKNOWN. HBC (Hortus Botanicus Calcuttensis), Wallich 5083D (K-001104687*, as to the left specimen with scape; P-02174775*–isolectoparatype of P. bakeri , p.p., as to the left individual, the right one is P. griffithii ).

Distribution:―NE Bangladesh (Silhet), E India (Khasia).

Habitat:―This species occurs at elevations up to 1220 m in Khasia.

Flowering:―October–November.

Etymology:―The specific epithet refers to a morphological feature of the inflorescence.

Taxonomic relationships:― Peliosanthes subspicata is most closely allied to P. violacea recircumscribed here, but differs by the shorter pedicels (0.5–2.5 vs. 1.5–8 mm long in flower), often smaller (to 9 vs. to 16 mm in diam.), cernuous (vs. usually horizontal or ascending) flowers, perigone segments minutely erose (vs. entire or nearly entire) along margins, staminal corona abruptly raised at periphery of the central orifice (vs. gradually and slightly raised towards the orifice), larger anthers (0.7–1.5 vs. 0.5–0.7 mm long), style with 3 narrow intercarpellary (septal) wings (vs. without wings), and larger stigma (0.9–1 vs. 0.4–0.7 mm wide). Specimens of Peliosanthes subspicata from India were previously classified by Baker (1879) under three varieties (var. violacea, var. minor, var. clarkei ) of P. violacea (see the above citation of specimens and Table 1). The specimen of P. subspicata collected by W. Gomez from Sylhet in Bangladesh (K-001104683*!) was identified as P. teta by Wallich (1831–1832 in 1828–1849, List. no. 5083A) or as P. violacea by Hooker (1892) (also probably by Baker in 1879). The distinctiveness of P. subspicata has thus been overlooked for a long time. Under Peliosanthes violacea ( var. violacea ), Baker (1879) cited a specimen collected by T. Lobb as from Burma ( Myanmar), but the record on the corresponding sheet (K-000099350!) shows that it came from Khasia, India. This specimen ( Figs. 5A, 5B, 5E ), representing P. subspicata , is therefore cited here as from Khasia. Flowers of Peliosanthes subspicata were recorded as “pale yellow green, reddish at disc” (J.D. Hooker & T. Thomson s.n., K-000099349!, Figs. 4 , 5C, 5D ), which probably meant that “the perigone (perianth) is pale yellow green, and the staminal corona in the central part of the flower is reddish”. In another specimen (R.L. Keenan s.n., K-000099345!), records on the label show that the perigone segments are green with purple margins.

Figures

FIGURE 4. Holotype of Peliosanthes subspicata from NE India: J.D. Hooker & T. Thomspm s.n. (K-000099349, p.p., excluding the second rightmost, distally trifurcate scape indicated by arrow).

FIGURE 5. Peliosanthes subspicata. A. Distal part of flowering stem. B. Part of inflorescence. C, D: Part of inflorescence at late anthesis. E. Part of abaxial surface of leaf blade, showing venation. Scale at D also for C. A, B, E: T. Lobb s.n. (K-000099350). C, D: J.D. Hooker & T. Thomspm s.n. (K-000099349).

FIGURE 6. Peliosanthes subspicata. A. Flower with slightly flattened segements, front view. B. Outer perigone segment, ventral view. C. Inner perigone segment, ventral view. D. Distal margin of perigone segment. E. Dehiscent anther on staminal corona, ventral view. F–H. Pistil; F, G. Side views from two different angles. Intercarpellary septal wings arrowed. H. View from above. I. Diagram of longitudinal aspect of flower. Scale at A for A–C; at D for D; at E for E–H. Drawn by Noriyuki Tanaka from: J.D. Hooker & T. Thomson s.n. (P- 00214609).