Harmsiopanax ingens is a very spiny palmlike mesocaul tree in the family (Araliaceae), endemic to the montane rainforests of central New Guinea which bears a terminal rosette of deeply lobed, dentate margined, usually (but not invariably) peltate leaves across, maple-like in shape, on equally long petioles. It ultimately attains a height of , at which point it bears a huge panicle of flowers high and equally wide; the largest above ground inflorescence of any dicot plantW. R. Philipson (1973), A Revision of Harmsiopanax. Blumea 21 (1): 84-85. (although Caloncoba flagelliflora of West Africa,E. Gilg, "Flacourtiaceae", DIE NATURLICHEN PFLANZENFAMILIEN (2nd edition; 1925) Vol. 21 pp. 377-457. Ficus geocarpa of the Malay Peninsula,"Moraceae - Ficus", FLORA MALESIANA Vol. 17 Part 2 (2005) pp. 40 & 461. and Ficus uncinata var. strigosa also of MalayaE.J.H. Corner, WAYSIDE TREES OF MALAYA (1952 edition) Vol. 1 p. 681. have larger subsurface panicles, each about in length). The panicles of H. ingens are unusual; the ultimate twigs being spikes each bearing about fifty tiny umbels, each umbel with 8 to 20 minute flowers; thus panicle, spike and umbel are all represented in a single inflorescence. Harmsiopanax ingens is monocarpic, and again the largest such plant among dicots. It was discovered in 1973 by W. R. Philipson. Its native name is makua.
References