Pollen morphology and pollination ecology of Amorphophallus species from North Western Ghats and Konkan region of India Sachin A. Punekar n , K.P.N. Kumaran Paleobiology Group, Agharkar Research Institute, G.G. Agarkar Road, Pune 411004, Maharashtra, India article info Article history: Received 16 February 2009 Accepted 6 May 2009 Keywords: India Amorphophallus Pollen Exine SEM data Pollination abstract The present paper reports on palynology and pollination ecology of eight taxa of Amorphophallus from North Western Ghats (NWGS) and Konkan region of India. Out of ten known pollen exine ornamentations of the genus, six are represented – psilate, striate, fossulate, verrucate, scabrate and the new type ‘pseudofossulate’ of Amorphophallus commutatus var. wayanadensis. These diverse pollen exine ornamentations can be utilized as an important taxonomic tool to distinguish taxa and also to resolve taxonomic problems (A. commutatus complex). The pollen of all eight taxa had retained their sculptured surface (exine ornamenatation type) after acetolysis. This clearly demonstrates that these taxa do not show susceptibility to the conventional acetolysis technique as reported earlier. The present study also highlights the importance of pollen surface morphology concerning phytogeography of the genus. Observation of pollination ecology of the studied Amorphophallus taxa reveals that all are mostly visited by beetles (Bostrichidae, Cetoniidae, Hybosoridae, Lyctidae, Nitidulidae, Rutelinae, Scarabaeidae, Staphylinidae), followed by flies (Drosophilidae, Muscidae), bees (Apidae: Trigone), ants (Formicidae, Dolichoderinae) and cockroaches (Blaberidae/Panesthiinae). The beetle families Bostrichidae, Lyctidae and Rutelinae, ant families Formicidae and Dolichoderinae and the cockroach family Blaberidae/ Panesthiinae are for the first time reported as visitors in the genus Amorphophallus. Most of the taxa display features characteristic of cantharophily (beetle pollination) except A. commutatus var. commutatus and A. commutatus var. wayanadensis, where Trigona bees are the actual pollinators. The beetles (Cetoniidae, Nitidulidae, Scarabaeidae) and bees (Apidae: Trigona) are the real pollinators for the Amorphophallus species of NWGS and Konkan while rest of the insects are mere visitors for alimentary/ food resources (staminode flowers, stigmatic fluid, pollen, appendix surface, appendix exudates) and using the inflorescences as mating and egg laying sites. Species belonging to the section Rhaphiophallus (Amorphophallus konkanensis and Amorphophallus sylvaticus) are pollinated by Epuraea – Haptoncurina sp. (Nitidulidae) beetles only. Generally, the species of Amorphophallus in NWGS and Konkan region with short flowering peduncle are always pollinated by dung beetles or scarabs while species bearing a long flowering peduncle are usually pollinated by Epuraea – Haptoncurina sp. (Nitidulidae) beetles and Trigona bees. Based on the comparative observations, five different phases of insect trapping in Amorphophallus taxa are characterized, focusing on the intricacies of pollination strategies of various pollinators. & 2009 Elsevier GmbH. All rights reserved. Introduction Amorphophallus Blume is a genus of palaeotropical aroids (Araceae) occurring in Africa, Madagascar, India, continental SE Asia, Malaysia and NE Australia (Mayo et al., 1997). The main centre of diversity is continental SE Asia and W Malaysia. At present the genus comprises about 200 species (Van der Ham et al., 2005). Studies dealing with the pollen of Amorphophallus are scarce, and most of them treat only one or a few species. The descriptions by Erdtman (1952), Sharma (1968) and Huang (1970, 1972) are not followed by any illustrations but only drawings without much detail. Thanikaimoni (1969), in his pioneering light microscopic study of Araceae pollen, covered eight species and Hetterscheid and his colleagues considered pollen characteristics in their taxonomic studies (Hetterscheid and Peng, 1995). However, none of these publications contain any micrographs and only an occasional drawing, which does not reveal much detail. Grayum (1992) presented a broader SEM survey of Araceae pollen of 23 species of Amorphophallus. He indicated that pollen as such is diverse in the family, and strongly advised undertaking of an extensive study. Subsequently, Van der Ham et al. (1998) made an extensive light and scanning electron microscopy of the pollen of ARTICLE IN PRESS Contents lists available at ScienceDirect journal homepage: www.elsevier.de/flora Flora 0367-2530/$ - see front matter & 2009 Elsevier GmbH. All rights reserved. doi:10.1016/j.flora.2009.12.024 n Corresponding author. Tel.: + 91 20 25653680x270; fax: + 91 20 25651542. E-mail address: sachinpunekar@gmail.com (S.A. Punekar). Flora 205 (2010) 326–336