An update on the distribution pattern and endemicity of three lesser-known tree species in the Western Ghats , India

The present communication reports an update on the distribution of three endemic tree species of the Western Ghats-Sri Lanka biodiversity hotspot, namely, Atuna indica (Bedd.) Kosterm., Paracroton integrifolius (Airy Shaw) N.P.Balakr. & Chakrab. and Phaeanthus malabaricus Bedd.  The discovery of these taxa in the Makutta Ghat of Kodagu District results in the extension of their northern range limits and further enriches the flora of Karnataka state by three more tree species.  Within the Western Ghats, these taxa were previously recorded only from the states of Kerala and Tamil Nadu, while Paracroton integrifolius (Airy Shaw) N.P.Balakr. & Chakrab. has also been recorded from Sri Lanka.  Nomenclature updates, detailed descriptions, conservation status and relevant notes on the habitat, phenology and distribution localization are supplied.  Additionally, field photographs and scanned herbarium specimens are provided to facilitate easy identification of these taxa in the field.

The present study establishes the extension in distribution range of these species from the earlier mentioned locations to newer sites in the Western Ghats in Karnataka.These findings result in the addition of three tree species to the floral diversity in the state and also warrant an extension of the endemicity of these taxa.

Study area
Kodagu (Coorg), a hilly district of Karnataka State, lies geographically between 12.423333 0 N and 75.7375 0 E and extends over an area of 4,102km 2 in the Western Ghats (Census 2011).This region is bordered by other districts, i.e., Hassan to the north, Mysore to the east, Dakshina Kannada to the northwest and districts of Kerala state to the south including Kasaragod, Kannur and Wayanad disricts.Kodagu has three wildlife sanctuaries, viz., the Brahmagiri, Pushpagiri and Talacauvery and one national park, namely, Nagarhole (=Rajiv Gandhi National Park), which is a major bio-reserve of this district.Makutta Ghat, is one of the species rich regions of Kodagu and harbours a number of endemic species of the Western Ghats.
Atuna indica was first located in Makutta Ghat during a visit in February 2014.Subsequently, in the month of March, in the same year Phaeanthus malabaricus in flowering and Paracroton integrifolius in fruiting stages were located from other locations of Makutta Ghat (Fig. 1).

Material and Methods
The taxa in their mentioned stages were photographed and their specimens collected.Relevant taxonomic notes and geographical coordinates (using hand held Garmin GPS) were also recorded.Herbarium specimens were prepared using standard protocols and were accessed into Herbarium JCB at the Centre for Ecological Sciences, Indian Institute of Science (IISc), Bengaluru and the Herbarium UASB at the University of Agricultural Sciences, GKVK Campus, Bengaluru.The specimens were carefully examined for identification and the determinations validated by further referring to the available taxonomic literature (Nair & Henry 1983;Nayar et al. 2006;Mabberley 2008;Karthikeyan et al. 2009;Balakrishnan et al. 2012) and online digital herbaria, HIFP (French Institute of Pondicherry), KFRI (Kerala Forest Research Institute, Peechi), K (Royal Botanic Gardens, Kew) and MO (Missouri Botanical Garden, St. Louis, Missouri).Digitization of specimens was carried out using in-house herbarium scanning equipment.Tall evergreen trees with thin, smooth, brown bark and reddish-blaze.Leaves simple, alternate, lamina 17-21 x 6-8 cm, elliptic-oblong, base acute, apex acuminate, margin entire, glabrous, chartaceous with 12-18 prominent lateral nerves; petioles 6-12 mm long, swollen at base; stipules free, lateral and lanceolate.Flowers bisexual in terminal or axillary corymbose racemes; bracts brown and hairy.Sepals united, tube funnel-shaped, 5-lobed; petals 5, white; stamens numerous; filaments basally connate; ovary 2-celled, ovules 2 in each cell; style filiform, basal; stigma truncate.Fruit a drupe, ca.4x3 cm, ovoid, smooth with 1-2 large stony seeds.

Atuna indica
Habitat: Understory of the wet evergreen forests, up to 800m altitude.
Flowers and Fruits: September-January.Distribution: Endemic to the Western Ghats of India.This species is restricted to the northwestern range of Nilgiris of Tamil Nadu (Ahmedullah & Nayar 1987;Nair & Henry 1983) and northern Kerala in Malappuram and Wayanad District (Sasidharan 2011;Nayar et al. 2006).Now as a new record from Makutta Ghat in Kodagu District of Karnataka.
Habitat: In wet evergreen forests, often in valleys and along streams banks.

Phaeanthus malabaricus
Bedd., Icon. Pl. Ind. Or. 16. t. 76. 1869;Hook. f., Fl. Brit. India 1: 72. 1872;Gamble, Fl. Pres. Madras 17(12). 1915;Ramach. et al., J. Econ. Taxon. Bot. 1: 96. 1980;Mohanan et al., J. Econ. Taxon. Bot. 5: 399. 1984; Ramach.& V.J. Nair, Fl. Cannanore Dist. 41. 1988;Debika Mitra in B. D. Sharma et al., Fl. India 1: 230. 1993;Sasidh. & Sivar., Fl. Pl. Thrissur For. 32. 1996;Sasidh., Fl. Shenduruny WS 17. 1997;Sasidh., Fl. Periyar Tiger Reserve 9. 1998;Mohanan & Sivad., Fl. Agasthyamala 59. 2002;Anil Kumar et al., Fl. Pathanamthitta 45. 2005 O P E N A C C E S S P a r tt n e r www .tt h r e a tt e n e d tt a x a .o r g I S S N 0 9 7 4 -7 9 0 7 ( O n l fi n e ) | I S S N 0 9 7 4 -7 8 9 3 ( P r fi n tt ) T h e fi n tt e r n a fi o n a l j o u r n a l o f c o n s e r v a fi o n a n d tt a x o n om y J o u r n a l o f T h r e a tt e n e d T a x a P u b l fi s h e r / H o s tt F o r F o c u s , S c o p e , A fim s , P o l fi c fi e s a n d G u fi d e l fi n e s v fi s fi tt h tt p : / / tt h r e a tt e n e d tt a x a .o r g / A b o u tt _ J o T T .a s p F o r A r fi c l e S u bm fi s s fi o n G u fi d e l fi n e s v fi s fi tt h tt p : / / tt h r e a tt e n e d tt a x a .o r g / S u bm fi s s fi o n _ G u fi d e l fi n e s .a s p F o r P o l fi c fi e s a g a fi n s tt S c fi e n fi fi c M fi s c o n d u c tt v fi s fi tt h tt p : / / tt h r e a tt e n e d tt a x a .o r g / J o T T _ P o l fi c y _ a g a fi n s tt _ S c fi e n fi fi c _M fi s c o n d u c tt .a s p F o r r e p r fi n tt s c o n tt a c tt < fi n f o@ tt h r e a tt e n e d tt a x a .o r g > ISSN 0974-7907 (Online) ISSN 0974-7893 (Print) OPEN ACCESS During our routine floristic exploration trips to Kodagu forests intended to strengthen and update the 'flora Karnataka' online database (Digital Flora of Karnataka 2014), the evergreen woody species, Atuna indica (Bedd.)Kosterm., Paracroton integrifolius (Airy Shaw) N.P. Balakr.& Chakrab.and Phaeanthus malabaricus Bedd.were discovered from the evergreen forest of Makutta Ghat along with other endemic species including Orophea malabarica Sasidh.& Sivar.and Orophea sivarajanii Sasidh.(Sankararao et al. 2015).The genus Atuna Raf.(Chrysobalanaceae) comprises nine species of the Indo-Malayan origin (Mabberley 2008; The Plant List 2014) of which two species A. indica (Bedd.)Kosterm.& A. travancorica (Bedd.)Kosterm.are endemic to the Western Ghats in Kerala and Tamil Nadu in India (Nayar et al. 2006).The genus Paracroton Miq.(Euphorbiaceae) comprises five species (The Plant List 2014) of which two species P. integrifolius (Airy Shaw) N.P.Balakr.& Chakrab.and P. pendulus subsp.zeylanicus (Thwaites) N.P.Balakr.& Chakrab.are endemic to Kerala and Tamil Nadu in India and Sri Lanka (Nayar et al. 2006; Balakrishnan et al. 2012), and the genus Phaeanthus Hook.f.& Thomson (Annonaceae) comprises 16 species distributed throughout the world (The Plant List 2014), one species of which, namely, P. malabaricus Bedd. is endemic to the Western Ghats in Kerala and Tamil Nadu.

Abstract:
The present communication reports an update on the distribution of three endemic tree species of the Western Ghats-Sri Lanka biodiversity hotspot, namely, Atuna indica (Bedd.)Kosterm., Paracroton integrifolius (Airy Shaw) N.P.Balakr.& Chakrab.and Phaeanthus malabaricus Bedd.The discovery of these taxa in the Makutta Ghat of Kodagu District results in the extension of their northern range limits and further enriches the flora of Karnataka state by three more tree species.Within the Western Ghats, these taxa were previously recorded only from the states of Kerala and Tamil Nadu, while Paracroton integrifolius (Airy Shaw) N.P.Balakr.& Chakrab.has also been recorded from Sri Lanka.Nomenclature updates, detailed descriptions, conservation status and relevant notes on the habitat, phenology and distribution localization are supplied.Additionally, field photographs and scanned herbarium specimens are provided to facilitate easy identification of these taxa in the field.Keywords: Endemic, Karnataka, Kodagu District, new records, range extension, Western Ghats.Three lesser-known tree species of Western Ghats Rao et al.

Figure
Figure 1.Map of Kodagu District, Karnataka showing specimen collection locations.