Pycnospatha Thorel ex Gagnep.

Between the years 1866 and 1868, during his Mekong expedition, Dr. Clovis Thorel collected an aroid in Laos. He recognized it as a new genus and called it Pycnospathium (sic!) in his field notes; he also described it in detail. His field notebook is kept in the Museum National d'Histoire Naturelle in Paris (P) and later F. Gagnepain used these field notes for his description of a new genus. A. Engler, the last monographer of the Araceae, 1905-1920, did not see the herbarium specimens in P and therefore this interesting aroid remained unknown to science (Engler, 1911) for a long time. Only approximately 75 yr after its discovery, F. Gagnepain (1941) described this new genus validly and named it Pycnospatha; the new species was described as Pycnospatha palmata Thorel ex Gagnep. In the meantime, a second species was collected in Thailand, which he also published at the same time as Pycnospatha arietina Gagnep. Living plants of Pycnospatha palmata were found by Mary Sizemore in Thailand about 130 yrs later, which are cultivated now. Gagnepain (941) included the genus Pycnospatha in the subfamily Calloideae and because of the naked, bisexual flowers he compared it with the genus Calla L., but also mentioned the difference of the entire leaves in Calla. Later, Gagnepain (942) in the "Flore Generale de 11ndo-Chine" listed Pycnospatha after Lasia Lour. and Cyrtosperma Griff., but did not made any division into tribes, therefore the exact systematic position of this new genus remained unclear. In the seventies of the last century, I visited the Paris herbarium and studied the material there. Later, (Bogner, 1973), I published a revision of the genus Pycnospatha and described its own subtribe for it, the Pycnospathinae Bogner, the second subtribe of the tribe Lasieae. Today the Lasieae are the only tribe in the separate subfamily Lasioideae and we, Mayo, Bogner & Boyce, 1997, did not recognize any more subtribes. Pycnospatha clearly belongs to the Lasioideae. The habit is similar to the neotropical genus Dracontium L. and mainly differs by its naked flowers; all other genera of the Lasioideae also have bisexual flowers but with a perigone. S. Y. Hu (1968) described a third species of the genus Pycnospatha and named it Pycnospatha soerensenii S. Y. Hu, but it is only a synonym of the earlier described Pycnospatha arietina Gagnep.