Miliusa sahyadrica G. Rajkumar, M. Alister, A. Nazarudeen & Pandur., 2016

Rajkumar, Gopalaprabhu, Alister, Mohan, Nazarudeen, Ahammed & Pandurangan, Alagramam Govindasamy, 2016, Miliusa sahyadrica, a new species of Annonaceae from the Western Ghats, India, Phytotaxa 284 (3), pp. 211-217 : 211-216

Miliusa sahyadrica G. Rajkumar, M. Alister, A. Nazarudeen & Pandur. , sp. nov., ( Figs. 1 , 2 )

Miliusa sahyadrica is similar to M. eriocarpa Dunn (1916: 58) in having spreading branches with the young portions pubescent, leaves elliptic or oblong-lanceolate, shortly petiolate, pubescent and pedicellate flowers. However, it clearly differs from M. eriocarpa in having axillary or sub terminal axillary flowers with orange tinge at base, sepals ciliate and pubescent without, inner petals basally connate, carpel golden pubescent, strictly ranging 1–4 in number and ripe fruits turn black with hispid appearance. The new species is also similar to M. gokhalaei Ratheesh, Sunjanapal, Kumar & Sivadasan (in Narayanan et al. 2012: 27) in having unequally round leaf bases and with slightly recurved inner petals; but distinct from the latter in having small flowers, anthers with few prominent hairs, golden pubescent ovary, globose fruits etc.

Type:— INDIA. Kerala: Kollam District, Palaruvi Forests, Aryankavu , 08 o 56 ’ 768 ’’ N, 77 o 10 ’ 253 ’’ E, ± 570 m, 20 August 2014, Rajkumar, Nazarudeen & Alister. TBGT 81369 (holotype: TBGT; isotype: MH) .

Shrubs 2–4 m tall, much branched; bark brownish gray; young branches pubescent. Leaves alternate, ovate or lanceolate, 4–7 × 2–3 cm, unequally cordate at base, margin ciliate, obtuse to acute or acuminate at apex, glabrous except midrib on both sides, lateral nerves 4–8 pairs, looping near margins, faint on both sides; petiole 2–3 mm long, flat above, pubescent. Flowers on young twigs, axillary and sub terminal axillary, solitary; pedicel yellow, 4–5 mm long, brown pubescent; bacts 2, alternate, ovate, at base of pedicel, ca. 1 mm long, ciliate, glabrous within, pubescent without. Sepals 3, valvate, deltoid, ca. 1.0 × 0.5 mm, golden pubescent without and margin, glabrous within except at base. Petals 6 (3+3), outer petals elliptic to ovate, ca. 1.5 × 1.0 mm, apex acute to acuminate, pubescent without, glabrous within; inner petals 8–9 × 3–4 mm, saccate, ovate, base connate, apex acute, slightly recurved, glabrous, pale yellow with orange tinge at base. Stamens ca. 20, in 3 whorls, 1mm across, connectives rounded, apiculate at top, with few hairs on anthers and base of the filament, anthers ca. 0.8 mm long, dehiscence by longitudinal slit; connectives short, obtuse, included; anthers extrose; torus conical, ca. 4 mm long. Carpels 4, ca. 2 mm long, oblong, yellow to golden tomentose; stigma linear-oblong, ca. 0.5 mm long, glabrous; ovule 1–2. Fruitlets 1–3, subsessile, globose, ca. 1 cm across, pubescent, beaked, young carpels creamy yellow, black when ripe; torus pubescent; fruit pedicel 4–5 mm long, Seeds 1–2, compressed or sub- globose with its centre grooved, ca. 8 mm in diameter, light yellow, surface smooth, endosperm ruminate.

Flowering and fruiting: —August–December; April–May.

Etymology:— The specific epithet refers to the Sahyadri Mountains, a synonym for the Western Ghats.

Distribution and habitat:— India (Kerala and Tamil Nadu), endemic. Restricted to Aryankavu and Courtallam Hills of the Agasthyamala Biosphere Reserve. It is found as an understory shrub with spreading branches growing along stream sides in the evergreen forests, 200– 600 m. Small populations of the species with moderate regeneration have been observed in two locations, viz. Palaruvi and Vettakodikana in the Aryankavu Forests of Kerala. Another population of more than10 mature individuals was observed at Courtallam Hills of Tamil Nadu adjacent to the type locality ( Fig. 3). It generally grows in association with Antidesma montanum Blume (1827: 1124) , Cyathocalyx zeylanicus Champion ex Hooker & Thomson (1855: 127) , Goniothalamus rhynchantherus Dunn (1914: 182) , Lasianthus acuminatus Wight (1846: 511) , Meiogyne pannosa ( Dalzell 1851: 3: 207) Sinclair (1951: 604), Mitrephora heyneana ( Hooker & Thomson 1855: 2: 110) Thwaites (1864: 8), Nothopegia aureo-fulva Beddome ex Hooker (1879: 40) , Orophea uniflor a Hooker & Thomson (1885: 111), Sageraea thwaitesii Hooker & Thomson (1855: 93) etc.

Taxonomic Notes:— Miliusa is classified in four informal groups, based on flower and/or inflorescence position and molecular phylogenetic analyses (Chaowasku & Kessler 2013, Chaowasku et al. 2013). The new species belongs to the Miliusa campanulata group, which is characterized by axillary, saccate flowers without pronounced glandular structures on inner petals. The only difference is that inner petals are not fully appressed from the base.

The diagnostic morphological characters of the new species with Miliusa e riocarpa, M. gokhalaei and M. montana are given in Table1.

Additional specimens examined:— INDIA. Kerala: Kollam district, Palaruvi, Aryankavu , 08 o 56 ’ 768 ’’ N, 77 o 10 ’ 253 ’’ E, ± 570 m, 21 October 2014 (with fruits), Rajkumar, Alister & Nazarudeen TBGT 81386 ; Kollam district, Palaruvi, Aryankavu , 08 o 56 ’ 768 ’’ N, 77 o 10 ’ 253 ’’ E, ± 570 m, 21 October 2014, 7 November 2014 (with fruits), Rajkumar, Alister & Nazarudeen TBGT 74900 ; Vettakodikana ± 450 m, 7 May 2015 (with flower & fruits), Rajkumar, Nazarudeen & Alister TBGT 77102. Tamil Nadu: Tirunelveli district , Courtallam, ± 500 m, 4 December 2015 (with flowers), Rajkumar, Nazarudeen & Alister TBGT 88286 .

Population structure and conservation status:— It has been observed that there are two populations in Palaruvi

(the type locality) each with 8–10 individuals. The third population at Aryankavu has more than 15 mature individuals.

The first two populations are located in an active tourist area and therefore prone to direct and imminent anthropogenic interference due to pollution and habitat degradation due to construction activities aiming at promoting tourism. The fourth population in Courtallam Hills contains more than ten mature individuals. The area of distribution of the new taxon is about 25 km 2 and the extent of occurrence (EOO) is less than 0.5 km 2 with less than 50 individuals. Therefore, Miliusa sahyadrica is treated as Critically Endangered (CR) Category (B1; C2+a (i); D) as per IUCN (2014).

Figures

FIGURE 1. Miliusa sahyadrica.A. Flowering branch. B. Flower bud. C. Flower. D. Sepal, outer view. E. Sepal, inner view. F. Outer petal, outer view. G. Outer petal, inner view. H. Inner petal, inner view. I. Inner petal, outer view. J. Flower with inner petals removed. K. Stamen, inner view. L. Stamen, outer view. M. Carpel. N. Mature fruit. Illustration by M. Alister from the type.

FIGURE 2. Miliusa sahyadrica.A. Habit. B. Twig showing leaves. C. Flowers. D. Unripe carpels. E. Hairs on stalk of fruit. F. Half-mature carpel. G. Fully mature carpel.