Argyreia manjolaiensis Karupp., Bharath & P.S.S.Rich., 2024

P. B. S., Yadav, S., Karuppusamy & Richard, P. S. S., 2024, A new species of Argyreia (Convolvulaceae) from the southern Western Ghats, India, Rheedea 34 (5), pp. 483-487 : 484-486

Argyreia manjolaiensis Karupp., Bharath & P.S.S.Rich. , Fig. 1 & 2 sp. nov.

Morphologically similar to A. fulgens Choisy but can be easily distinguished from 2–2.5 cm long petiole ( vs. 3–7 cm long), a cordate lamina base ( vs. rounded), a hairy abaxial surface of the lamina ( vs. glabrous), 12 secondary veins ( vs. 18–22), 10–12-flowered inflorescence ( vs. 5–7-flowered), 3 bracts ( vs. 2), subequal or unequal sepals ( vs. equal) and a corolla tube that is pale purple at the base and milky white at the throat ( vs. dark purple throughout). A detailed morphological comparison is provided in Table 1 .

Type: INDIA, Tamil Nadu, Tirunelveli, Manimuthar falls, on the way to Manjolai , above 684 m, 20.08.2023, Karuppusamy, Bharath & Richard 3121 ( holo SGH!; iso MCCH! MH!).

A woody climbing shrub, grows up to 24 m or more. Stems terete, green, sericeous. Leaves dorsiventral, alternate; petioles terete, 2–2.5 cm long, green, sericeous as in stem, shallowly grooved; lamina ovate, 5.6–6.8 × 4–4.5 cm, base cordate, apex acute to acuminate, margins entire, ciliate, partially hairy adaxially, densely silvery shiny tomentose abaxially, secondary veins 12 pairs, raised prominently below. Inflorescence an axillary, 10–12-flowered, capitate cyme; peduncles 2.5 cm long, green, hairy like stem, slightly longer than petioles. Bracts 3; outer bract oblonglanceolate, 2–2.5 × 0.6 cm; inner two lanceolate or falcate, 1.5–1.8 × 0.4 cm, densely sericeous outside, except overlapped areas, hairy inside, minutely 5–9 veined inside, margins entire, apex acute. Flowers subsessile; pedicels c. 0.2 cm long, hairy. Sepals 5, ovate-lanceolate, subequal or unequal; outer two narrow, 1–1.2 × c. 0.4 cm; inner three broad, c. 0.6 × 0.5 cm, margins entire, hyaline, apex acute, glabrous inside, sericeous all over outside except overlapped areas. Corolla infundibuliform, c. 5 cm long, c. 5 cm across, purple at the base, milky white near throat; tube dark purple inside, hairy on mid-petaline bands. Stamens 5, unequal, 3 short, 2 long; longer stamens c. 1.5 cm long; shorter stamens 0.8–1 cm long; filaments white, with few glandular trichomes at the base; anthers basifixed, c. 0.4 cm long. Ovary ovoid-ellipsoid, pale green, encircled by annular ring; style single, c. 1 cm long; stigma biglobose, white.Fruit a globose berry, 1.5–2 cm across, topped by remnant of style base, yellow when ripened. Seeds 4, ellipsoid to obovoid, 1.5–2 × 3.5–6 mm, white, glabrous.

Flowering & Fruiting: Flowering from July to September; fruiting from August to November.

Ecology: The species occurs in tropical dry deciduous and semi-evergreen forests at elevantions of 450–600 m, inhabiting exposed areas of the forests and climbing over trees. Some of the associated taxa include Nothopegia heyneana (Hook.f.) Gamble , Semecarpus anacardium L.f. ( Anacardiaceae ), Careya arborea Roxb. ( Lecythidaceae ), Cleistanthus travancorensis Jabl. ( Phyllanthaceae ), Filicium decipiens (Wight & Arn.) Thwaites ( Sapindaceae ), Grewia tiliifolia Vahl ( Malvaceae ), Capparis diversifolia Wight & Arn. ( Capparaceae ), Strobilanthes parvifolia J.R.I.Wood ( Acanthaceae ), Eugenia calcadensis Bedd. ( Myrtaceae ), Terminalia anoegeissiana Gare & Boatwr. ( Combretaceae ), and Tectona grandis L.f. ( Verbenaceae ).

Distribution: Presently known only from the type locality of Manimuthar waterfalls, on the way to Manjolai, Tirunelveli district, Tamil Nadu, India ( Fig. 2 ).

Etymology: The new species is named after the type locality, Manjolai estate in Kalakadu-Mundanthurai Tiger Reserve of southern Western Ghats.

Conservation status: Fewer than 25 mature individuals of Argyreia manjolaiensis , with an extent of occurrence (EOO) of 30 km 2, area of occupancy (AOO; AOO based on user defined cell width [ 3 km]) 63 km 2 have been found at the type locality. According to the latest IUCN conservation status assessment guidelines (IUCN Standards and Petitions Committee, 2024 ver. 2024-1), Argyreia manjolaiensis is provisionally assessed here as Critically Endangered (CR).

Figures

Fig 2. Map showing the distribution of Argyreia manJOLaiensis Karupp. Bharath & P.S.S.Rich. (Map prepared by P. Bharath Simha Yadav using QGIS 3.32.3).

Fig. 1. Argyreia manJOLaiensis Karupp., Bharath & P.S.S.Rich.: a. A flowering twig; b. Leaf–abaxial view; c. Leaf–adaxial view; d. Leaf abaxial surface–Closeup view; e. Leaf–tip; f. Inflorescence; g. Bracts; h. Flower–frontview; i. Sepals; j. Flower–side view; k. Flower cut open showing stamens and pistil; l. Stamens; mPistil (Photos P.S.S.Richard)

Tables

Table 1.Comparison of morphological characters between Argyreia manjolaiensis and A. fulgens

Characters	A. manjolaiensis sp. nov.	A. fulgens Choisy
Petioles	2–2.5 cm long, without any glands	3–7 cm long, with two protuberances like glands at point of attachment with lamina
Lamina	Cordate at base; hairy abaxially	Rounded at base; glabrous
Secondary veins	12, green in young leaves	18–22, purple in young leaves
Inflorescence	Capitate cyme, 10–12-flowered	Dichotomously branched cyme, 5–7-sflowered
Peduncles	Equalling or longer than petioles	Shorter than the petioles
Bracts	3, oblong-lanceolate	2, linear-oblong
Sepals	Subequal or unequal, 1–1.2 × 0.4 – 0.5 cm	Equal, 0.5–0.7 × c. 1 cm
Corolla	c. 5 cm long, 5 cm across; tube purple at the base, throat milky white	2.5–3.5 cm long, 2–2.5 cm across; tube purple throughout