Hunteria zeylanica (Retz.) Gardner ex Thwaites (Magnoliopsida: Gentianales: Apocyanaceae)—new addition and first genus record to the flora of Karnataka

The present study reports the new distribution record of Hunteria zeylanica (Retz.) Gard. ex Thw., tree from Karnataka part of Central Western Ghats.


NOTE
Hunteria is a genus of Apocynaceae comprising 13 species and was first described in 1824 by Roxburgh (POWO 2023).In southern India it is mainly represented by the tree species Hunteria zeylanica (Retz.)Gardner ex Thwaites which is native to eastern Africa and to Indo-Malaysia (WCSP 2023).In southern India, it is recorded from the evergreen forests of Kerala and Tamil Nadu.During the field work in Dodmane Ghat of Uttara Kannada district, Karnataka, a small tree was collected from the wet evergreen forest area.On closer identification with local flora (Gamble 1921;Saldanha 1984Saldanha -1996;;Bhat 2003;Punekar & Lakshminarasimhan 2011) and further confirmation from Botanical Survey of India, southern regional centre, Coimbatore, it was confirmed to be Hunteria zeylanica (Retz.)Gardner ex Thwaites.Its earlier distribution was reported from the southern Western Ghats of Wayanad, Palakkad, Thrissur, Idukki, Kollam, & Thiruvananthapuram districts of Kerala and Kanyakumari & Tirunelveli of Tamil Nadu (Sasidharan 2011).The present study reports this evergreen tree Hunteria zeylanica (Retz.)Gardner ex Thwaites, for the first time from Karnataka part of the Western Ghats.
Habitat: Evergreen to semi-evergreen forests.
Flowering and Fruiting: February-June.Distribution: Eastern Africa and Indo-Malesia.Note: This plant slightly differs from southern Western Ghats population with having more broader leaves and corolla more twisted and white with folded petal.
Habitat and associated plants: The tree species occurred in evergreen forest along with several other trees such as Diospyros paniculata, D. pruriens, Holigarna grahamii, Hydnocarpus pentandra, Hopea ponga, and Syzygium gardneri.Only two trees of Hunteria zeylanica were encountered in the region, and were not found elsewhere even after extensive surveys in Uttara Kannada district.Though this species has Indo-Malesian distribution, in India it has a narrow distribution with very small population surviving in the central Western Ghats, Karnataka, while the other populations are in states of Kerala and Tamil Nadu.Presently the tree species is in a protected forest and is found intact with no immediate threat.But as the numbers are very small, these trees can swiftly cascade towards their inevitable extinction due to anthropogenic pressures such as habitat loss by land encroachment for Areca cultivation along water courses, even inside protected areas.Hence

Image 1 .
Hunteria zeylanica: A-Flowering leafy twig from the locality | B-Flowering twig close up | C-Leaf close up dorsal side | D-Flower close up.© G. Ramachandra Rao.