Swertia raveendrae Shahina & Nampy, 2015

Nampy, Santhosh, Shahina, P. M., Haseena, T. & Ashwini, H. S., 2015, A taxonomic revision of Swertia L. (Gentianaceae) in South India, with one new species and seven lectotypifications, Phytotaxa 195 (1), pp. 31-52 : 44-48

6. Swertia raveendrae Shahina & Nampy , sp. nov.

Swertia raveendrae is similar to S. lawii in having watch pocket-shaped glands with compound fimbriae at the base of each corolla lobe, from which it differs by its cordate-orbicular leaves, densely paniculate cymes, small (0.3–1 cm long), ovate-elliptic bracts, and calyx not exceeding the corolla in bud.

Type: — INDIA, Karnataka, Chickmagalur district, Bababudan hills, 13.52˚ N, 75.75˚ E, 1895 m, 7 November 2013, P. M. Shahina, H. S. Ashwini & A. P. Janeesha 134720 (Holotype CALI, isotype MH).

Annual, glabrous herbs, 13–38 cm tall. Stems 4-angular, winged (wings 0.1–0.2 mm broad). Leaves sessile; blades cordate-orbicular, 2–2.5 × 1.2–1.8 cm; apex obtuse; base sub-amplexicaul, with 3–5 secondary veins each side. Cymes dense, axillary or terminal panicles, 1–3-flowered; bracts ovate-elliptic, 0.3–1 × 0.18–0.5 cm; pedicels 0.5–1.8 cm long. Calyx lobes 4, ovate-oblong, 0.5–1 × 0.05–0.15 cm, 3-veined, divided almost to the base; apex acute. Corolla dark purple with blue veins; tube 0.5–1.5 mm long; lobes obovate, 0.8–1.5 × 0.4–0.6 cm; apex obtuse-acute; gland 1 at the base of each corolla lobe, ovate, watch pocket shaped; fimbriae white, inserted on a green scaly base, 0.04–0.6 cm long. Stamens 4; filaments 1.2–3.5 mm long, white, dilated at base, 1–4 hairs at base; anthers oblong, 0.5–1 × 0.3–0.7 mm, brown. Ovary oblong, 6.5–8 × 1–2 mm; style 0.1–0.8 mm long; stigmatic lobes orbicular, 0.02–0.6 × 0.4–0.65 mm. Capsules oblong, 5–10 × 1–2.5 mm. Seeds polyhedral, 0.3–0.6 × 0.1–0.4 mm; testa warted, brown.

Flowering & fruiting:— September–December.

Habitat:— Among grasses in rocky areas.

Distribution:— Although presently known only from the type locality, it is likely to present in other parts of South India ( Figure 7 ).

Conservation status:— Swertia raveendrae is currently known only from a single population in an unprotected area. It shows local abundance with a maximum of 35 plants in the population. These information indicate that the species may belong to Vulnerable category (IUCN category VUD2), with future possibility of further ecological disturbances.

Etymology:— The specific epithet is named in honour of Prof. K. Raveendrakumar (Former Head, Department of Botany, Sri Vyasa N.S.S. College, Wadakanchery), who attracted the second author to the field of Taxonomy.

Notes: — Swertia raveendrae differs from S. lawii by several vegetative and floral characters (Comparison of the two species are given in Table 1 and Figure 8 ). S. raveendrae grows in association with different species of grasses, Eriocaulon sp. , Murdannia lanuginosa (Wallich ex Clarke) Brückner (1930: 173) and Oldenlandia stocksii Hooker (1882) .

7. Swertia trichotoma (Wight & Arnott) Wight ex Clarke (1883: 126) . Ophelia trichotoma Wight & Arnott (1850: 175) . Type:— INDIA, Nilgiris, 1830, Wight 2573 (Lectotype E 001958! designated here).

Ophelia umbellata Wight (1850: 175) . Swertia umbellata (Wight) Shah (1988: 82) nom. illeg., non Ruiz & Pavon (1802). Type:— INDIA, Nilgiris, s. die, Wight s.n. (Lectotype K 000854486! designated here).

Annual, glabrous herbs, 7–75 cm tall. Stems 4-angular, winged (wings 0.2–0.4 mm broad). Leaves sessile-subsessile; blades elliptic-lanceolate, 4–6 × 0.3–1.5 cm, with 3–5 secondary veins each side; apex acute-acuminate; base attenuate. Cymes axillary or terminal umbels, 1–5-flowered; bracts elliptic, 0.3–0.6 × 0.2–0.6 cm; pedicels 2–4.5 cm long. Calyx lobes 4, lanceolate, 4–10 × 2–4 mm, divided almost to the base, 3-veined; apex acute or acuminate. Corolla often white, sometimes blue; tube 0.5–1 mm long; lobes 4, oblong or obovate, 8–14 × 2–5 mm, 3-purple veined; apex acuminate; glands 1 at the base of each, orbicular, shallow pitted, situated at the base of each corolla lobe; fimbriae compound, 1–1.8 mm long. Stamens 4; filaments 3–5 mm long, white; anthers 0.5–1.5 × 0.3–0.7 mm, yellow. Ovary sessile, oblong, 4.5–6.5 × 1–2.5 mm; style 0.1–0.3 mm long; stigmatic lobes orbicular, 0.2–0.4 × 0.1–0.3 mm. Capsules oblong, 5–7 × 1–1.5 mm. Seeds oval with shallow sunken pits, 0.2–0.5 × 0.1–0.3 mm; testa with small projections along the margins, brown.

Chromosome number:— 2n = 26 ( Mallikarjuna et al. 1987).

Flowering & fruiting:— July–February.

Habitat:— Grasslands.

Distribution:— South India, endemic.

Conservation status:— The range of occurrence of this species is estimated to be less than 5000 km ². A counting decline is observed, inferred, and projected in its (a) area of occupancy; (b) area, extent and/or quality of habitat and (c) number of locations or subpopulations. Therefore, we consider this species to be Endangered (EN B1 2ab) according to the IUCN criteria.

Use:— The leaf extract serves as a remedy for wormicidal use in animals ( Rajan et al. 2005).

Specimens examined:— Kerala, Idukki district, Silent Valley , 16 December 2012, A. J. Robi & K. M. Manudev 4973 ( CALI) ; Ibid., 17 December 2012, A. J. Robi & K. M. Manudev 4984 ( CALI). Palakkad district, Silent Valley , 2 November 2013, K. M. Manudev & P. M. Shahina 134727 ( CALI). Tamil Nadu, Coimbatore district , Coimbatore, s. die, C. E. C. Fischer 1310 ( CAL). Dindigul district , Kodaikanal, 8 January 1987, K. M. Matthew 48124 ( RHT) ; Sirumalai, August 1920, s.coll. 2757 ( RHT). Nilgiri district, Avalanche , 17 August 1930, V. Narayanaswami 4426 ( MH) ; Nilgiris , s. die, s.coll. s.n. ( MH) ; Ibid., 1891, Stahl s.n. ( CAL) ; Ibid. , 9 November 1884, J. S. Gamble 15715 ( CAL) ; Ooty , 24 October 1904, C. A. Barber 6549 ( MH) ; Ibid. , 11 March 1870, C. B. Clarke 10675 ( CAL) ; Upper Bhavani-Bangi Halla , 19 December 1970, B. V. Shetty 37500 ( MH) ; s.loc., s. die, J. S. Gamble s.n. ( MH). Ramanathapuram district, Mudaliaruthu-Virusali , 18 February 1979, N. C. Nair 60948 ( CAL, MH) .

Notes:— Robert Wight (1850: 175) described both Ophelia umbellata and O. trichotoma presenting only floral analytical details, without any accompanying description. Subsequently, Clarke (1883) inadvertently validated the combination Swertia trichotoma based on Ophelia trichotoma and cited O. umbellata Wight as its synonym. However, Shah (1988) considered both Ophelia umbellata and Ophelia trichotoma as invalid names (nom. nud.). Shah also published the new combination Swertia umbellata for this species, which is a later homonym of S. umbellata Ruiz & Pavon (1802: 21) , and is therefore illegitimate (Melbourne Code, Art. 11.5). According to Article 38. 7 of the Melbourne Code (2012), Ophelia umbellata and O. trichotoma are valid names. Since Ophelia umbellata and O. trichotoma are conspecific, and Swertia umbellata (Wight) Shah (1988: 82) is a later homonym of S. umbellata Ruiz & Pavon (1802: 21) , Swertia trichotoma (Wight) C.B. Clarke is the correct name for this species.

There are several specimens of Ophelia trichotoma and Ophelia umbellata collected by Wight from South India in the E and K herbaria. Most matching specimens among them are designated here as the lectotypes of both Swertia trichotoma and Swertia umbellata .

Swertia trichotoma is similar to S. corymbosa by having orbicular glands with compound fimbriae, from which it differs by its umbellate inflorescence and seed testa with small projections.

Figures

FIGURE 7. A & B. The distribution and habitat of S. raveendrae.

FIGURE 8. Comparison of S. raveendrae & S. lawii A–F S. raveendrae. G–L S. lawii A, G. Inflorescences; B, H. Buds- see the length of calyx; C, I. Bracts; D, J. Calyces; E, K. Flowers; F, L. Petals (A–F from P.M. Shahina, H.S. Ashwini & A.P. Janeesha 134720; G–L from P.M. Shahina & S. Nampy 134724).