Barleria spinosa Wall., Numer. List

Barleria spinosa Wall., Numer. List View in CoL : n. 2497. 1830, nom. nud. FigS. 1–3 View Fig View Fig View Fig

Perennial, prostrate or decumbent herbs with woody rootstock, spreading up to 80 cm long in diam., rooting at basal nodes. Stems purplish to green when young, spreading, well-branched, angular, winged, glabrous or very few hairs only at the nodes of young branches, internodes 3–18 mm long. Leaves sessile or sub-sessile, isophyllous, oppositedecussate, oblance-ovate to broadly obovate, 9–22 × 4–7 mm, base attenuate, margins undulate with minutely serrulate, apex obtuse or rounded with spinose apical process, glabrous throughout; midvein broad at base, lateral veins 3–5 pairs, conspicuous on lower surface. Inflorescence a spike, broadly ovoid due to spreading or diverged fertile bracts, terminal or axillary, 14–20 mm long. Bracts: sterile ones in 2–5 pairs, oblong or lance-ovate, 10–18.5 × 3.3–4.5 mm, margins serrulate, apex caudate with spinose apical process; fertile bract 1, similar to sterile bracts except the size (11–18.5 × 2.7–3.2 mm). Bracteoles 2, oblong, 14–19 × 2–3.3 mm, margins minutely ciliolate, apex caudate with spinose apical process, sparsely hirsute on both surfaces. Calyx 5-lobed, heteromorphic, margins pilose below, glabrous above, apex caudate with spinose apical process, pilose inside, glabrous outside; anticous lobes 2, unequal, overlapping, connate at base (less than onefourth of their total length, i.e., 1.3–2.1 mm); lobes elliptic (broadly elliptic in fruiting calyx), 9.5–11 × 1.5–2.8 mm; posticous lobe 1, elliptic (broadly elliptic in fruiting calyx), 9.7–10.8 × 2.5–5 mm; lateral lobes 2, equal, arcuate, linear (elliptic in fruiting calyx), 8.9– 11.2 × 0.8–1.2 mm. Corolla bilabiate, 14.8–16 mm long, white with many purplish brown markings throughout inside and yellow dots or patches on the palate; tube 8.4–9.6 mm long, cylindric below, 4.2–4.8 mm long, glabrous inside, abruptly expanded above, 3.7–4.7 mm long, retrorsely hirsute just above the cylindrical tube to throat on either side of lower lip inside, retrorsely hirsute throughout outside; upper lip arcuate, 2.8–4.2 × 4.8–5.7 mm, margins entire, apex minutely 2-lobed ( 0.61–0.66 mm long), each lobe 3-veined; lower lip 3-lobed, 6.3–7.2 mm long including lobes; middle lobe broader than the lateral lobes, sub-orbicular, 2.7–3.2 × 5.2–5.3 mm, crenulate, 3-veined; lateral lobes oblong, 1.8–2.7 × 2.5–3.3 mm, 3-veined. Stamens 4, didynamous; anticous (longer) filaments 4.3–5.7 mm, posticous (shorter) filaments 2–4 mm, purple-striped, glabrous; anthers oblong, divergent, 1.4–2.0 mm long, white to yellowish, sparsely hairy at the base of the slit, scabrous at the connectives, longitudinally dehiscing. Ovary sub-globose, 1.4–1.5 × 0.8–1.1 mm, glabrous, 2-loculed; ovules 2 in each locule; style 9.3–10 mm long, antrorsely bristled-hairy; stigma entire. Capsules lanceovoid, 6.3–7.1 × 2.7–2.9 mm, glabrous, yellowish to brown; seeds 1 or 2 fertile, ovoid, 3.5–3.6 × 2.4–2.7 mm, flat, densely clothed with hygroscopic white hairs on both surfaces (longer than seed).

Flowering & fruiting: Flowering from October to March and fruiting from January to July.

Habitat: This species usually grows on dry barren wastelands with black cotton soil, at elevations ranging from 50 to 130 m.

Distribution: India, endemic to Tamil Nadu.

Etymology: The specific epithet “ spinosa ” refers to the spinose apical process of the oblance-ovate to broadly obovate leaves, bracts and bracteoles.

Specimens examined: INDIA, Tamil Nadu, Coimbatore district, Coimbatore plains, s.d., R. H. Beddome 459 ( BM [ BM013860265 digital image!]); Madurai district , T. Kallupatti, N 09°78'46.64", E 77°93'74.03", 131 m, 07.01.2022, G. Gnanasekaran & A. F. J. King 12868, 12869; T. Pudupatti , N 09°46'29.1", E 77°54'50.0", 130 m, 07.01.2022, G. Gnanasekaran & A. F. J. King 12867 (Madras Christian College Herbarium, Chennai); Ramanathapuram district , Muthukulathur, 75 m, 18.06. 1978, N. C. Nair 57329; Pandalgudi, 09.03.1953, C. H. Maduram 21783; Perayanur, 24.02.1953, J. Sakharam Rao 21765; Perunazhi, 75 m, 14.01.1989, V. Balasubramaniam 2063; Sethupathinagar, 50 m, 11.02.1987, V. Balasubramaniam 1269 ( MH); Tiruchirappalli district , Ponmalaipatti, 50 m, 16.12.1985, K. M. Matthew 18659; Tiruchy, September, s.coll., s.n. ( RHT); Tirunelveli district , Siwalaperi (Sivalaperi), 02.10.1795, Rottler s.n. ( K [ K000950057 digital image!]); Thoothukudi district , Kovilpatti, 18.07.1901, C. A. Barber 3429 ( MH); Kovilpatti, N 09°12'77.2", E 77°82'35.8", 120 m, 08.01.2022, G. Gnanasekaran & A. F. J. King 12877, 12878 (Madras Christian College Herbarium, Chennai); Virudhunagar district , Maittanpatti, N 09°40'02.7", E 77°57'58.2", 126 m, 08.01.2020, G. Gnanasekaran & A. F. J. King 12876 (Madras Christian College Herbarium, Chennai); Sattur, May 1903, C. A. Barber s.n.; Sattur, May 1903, C. A. Barber s.n. ( MH). Peninsula Indiae Orientalis, s.d., s.coll., s.n. ( BM [ BM013860263 digital image!]); s.d., R. Wight 1972 ( E [ E01024337 , E01024338 , E01024339 digital images!]); s.d., R. Wight 2232 ( C digital image!); India, s.d., Royle s.n. (hb. J. S. Mill) ( K [ K000950058 digital image!]); Maisor (Mysore) & Carnatic, s.d., G. Thomson s.n. ( C, G [ G00390434 ], K [ K000950141 ] digital images!) GoogleMaps .

Conservation status: The species is provisionally assessed here as ‘Near Threatened [NT]’ using the IUCN Red List Categories and Criteria version 15.1 ( IUCN, 2022). The examination of herbarium specimens in national and international herbaria (digital images) with our fresh collections shows that this species is distributed in 13 different localities in the state of Tamil Nadu. The species distribution polygon has been prepared to calculate the Extent of Occurrence (EOO) and Area of Occupancy (AOO) for this species using GeoCAT ( Bachman et al., 2011) available at http://geocat.kew.org/. The result of this analysis shows that the EOO and AOO are 30,461 km ² and 52 km ², respectively. Although the AOO of this species fits well for the Endangered [EN] category as per Criterion B2, the minimum number of conditions required to qualify under the EN category is insufficient. However, the EOO and the number of locations show that it might be eligible for the threatened categories at any time in the near future. Furthermore, it is observed in the present study that habitat quality is declining due to various developmental activities and the spread of invasive alien species ( Prosopis juliflora (Sw.) DC. of Fabaceae ), which may pose a severe threat to many subpopulations of this steno-endemic species.