Anisochilus kanyakumariensis Shinoj & Sunojk., 2018

Shinoj, Kalathummarath & Sunojkumar, Purayidathkandy, 2018, Anisochilus kanyakumariensis (Lamiaceae): a new species from the Western Ghats, India, Phytotaxa 333 (1), pp. 99-107 : 100-101

Anisochilus kanyakumariensis Shinoj & Sunojk. , sp. nov. (Figs. 1 & 2)

Anisochilus kanyakumariensis is similar to A. carnosus and A. paniculatus , but differs from both species by its decumbent habit (vs. erect in A. carnosus and erect or ascending in A. paniculatus ); orbicular leaf, 4–5 × 3–4 cm (vs. broadly ovate, 5–7 × 3–5 cm in A. carnosus and ovate or elliptic, 4–6 × 2–3 cm in A. paniculatus ); petiole 0.5–1 cm long (vs. 4–5 cm in A. carnosus and 2–3 cm in A. paniculatus ); inflorescence narrow cylindrical, 2–3 cm long (vs. tetragonal, 3–6 cm in A. carnosus , and small ovoid, 1.5–2 cm in A. paniculatus ); bracteoles ovate as in A. paniculatus (vs. lanceolate in A. carnosus ); densely villous calyx (vs. pubescent calyx in A. carnosus and A. paniculatus ); densely villous corolla, 4–6 mm long (vs. slightly pubescent corolla, 8–9 mm long in A. carnosus , and pubescent corolla ca. 7 mm long in A. paniculatus ).

TYPE: — INDIA. Tamil Nadu: Kanyakumari district, Maruthwamala, 8º07’53.90”N, 77º30’24.48”E, 70–90 m, 30 October 2015, K. Shinoj & P. Sunojkumar CU138400 a (holotype CALI!), CU138400 b-c (isotypes CALI!), CU138400 d (isotype MH!).

Decumbent annual or short lived perennial herbs, branches succulent, 50–70 cm long. Stem terete, glabrescent to pubescent. Leaves petiolate, orbicular, 4–5 × 3–4 cm, apex rounded or obtuse, margin crenulate, adaxial surface rusty tomentose, abaxial surface tomentose, lateral veins 5–6 and 2–3 basal veins on each side of the midrib, secondary and tertiary reticulate venation prominent beneath; petiole short, 1–2 cm long, pubescent. Inflorescence terminal, main axis 15–20 cm long; secondary branches 5–7, arranged opposite decussate, each 5–10 mm long, both main and secondary branches end in a congested spike which are ovoid to cylindrical ≥ 20 mm long. Bract dome-shaped, 1.5 × 1.6 mm, early caducous; bracteoles dome-shaped 0.75 mm × 0.76 mm, ciliate, caducous. Calyx ovoid, 2–3 mm long when posterior lip opened and 1.5–2 mm long when posterior lip closed, densely villous; posterior lip 1-lobed, acute to acuminate, ciliate to villous, hairs 4–5 celled. Corolla 4–5 mm long from base to top of lower lip, white with a pink tinge at inner surface of posterior teeth, corolla base tube funnel shaped and densely villous outside. Stamens 4, free, attached at mouth of the corolla tube, didynamous, posterior pair attached just below anterior but not united, filament of the posterior 1.5–2 mm long, of the anterior pair 2–2.5 mm long, included in anterior corolla lip; anthers bilobed, dorsifixed, ca. 0.3 mm long, orange to brown (when mature), dehisces longitudinally. Mericarps circular or widely elliptic, 818–824 μm × 745–750 μm brownish, surface undulate, reticulate, cells faintly polygonal.

Etymology: —The species is named after Kanyakumari District of Tamil Nadu from where the specimens were originally collected (It was collected from the rock crevices of Maruthwamala and Chunkankadai Hill of Kanyakumari District).

Distribution, habitat and ecology: — Anisochilus kanyakumariensis is only known from Maruthwamala and nearby hills of Kanyakumari District in Tamil Nadu, India ( Fig.5 ). The plant grows on rock crevices. It is usually found growing in association with herbaceous Jusicia diffusa Sm ex. T. Anderson, Leucas nepetifolia Benth. , and grasses like Apluda mutica L. and Sehima nervosum (Rottler) Stapf.

Phenology: —Flowering from June to January, fruiting from July to March.

Additional specimens examined (paratypes): — INDIA. Tamil Nadu, Kanyakumari district, Chunkankadai Hill , elev. 120 m, 8º12’11.28”N, 77º23’12.78”E, 21 July 2016, K. Shinoj & P. Sunojkumar 145485 (CALI!) ; Kanyakumari district, Maruthwamala , elev. 70 m, 8º07’54.54”N, 77º30’20.69”E, 20 November 2016, K. Shinoj & P. Sunojkumar 151006 (CALI!) ; Kanyakumari district, Maruthwamala , 22 June 1984, T. K. Abraham, P. Mohan Kumar & P. J. Mathew 283 (TBGT!) .

Conservational status: — Anisochilus kanyakumariensis grows on rock crevices, with an area of occupancy smaller than 20 km 2. Based on field observations, it is estimated that the total number of individuals of this endemic species does not exceed 200 in two different localities. Moreover a fragmented distribution with a very few population was met in Chunkankadai Hills. Therefore, we suggest that Anisochilus kanyakumariensis should be classified as endangered (E) according to the criteria B1b of IUCN (2012).

Discussion: —After critical study and comparison with the protologues and type specimens of other species of this genus we came to the conclusion that Anisochilus kanyakumariensis is morphologically more similar to A. carnosus and A. paniculatus , but differs from them in having some unique characters like decumbent habit, very close inflorescence, woolly calyx, rusty appearance of leaf and mericarp surface.

FIGURE 1. Anisochilus kanyakumariensis . A, habit; B. inflorescence; C. single congested spike; D. stem; E. leaf; F. corolla; G. dissected corolla tube; H. calyx; I. stamens; J. stigma; K. ovule; L. dissected calyx.

Figures

FIGURE 5. Distribution map of Anisochilus kanyakumariensis (●).