Cyrtosperma

Abstract: A reinvestigation of more than 200 new specimens of Keratosperma allenbyense Cevallos-Ferriz et Stockey from the Middle Eocene Princeton chert allows a more detailed comparison with living Araceae and provides evidence for the evolution of the lasioid clade. The anacampylotropous seeds possess a warty seed coat, single dorsal ridge, and two lateral ridges. Idioblasts that may have contained raphides are scattered in the outer integument. The seed has a thin micropylar cover and an epistase, with evidence of mucilage in the space between these two structures. The raphe is embedded in the seed coat and parallels the concave surface of the seed. At the chalazal end of the seed, there is a prominent hypostase and podium. Endosperm tissue with dark contents and monocotyledonary embryo are present, but in most specimens these tissues are replaced by fungal hyphae. Anatomical comparisons with the extant lasioid taxa Cyrtosperma merkusii (Hassk.) Schott and Urospatha sagittifolia (Rudge) Schott were made. A reconstruction of K. allenbyense constructed from serial sections allowed the fossil to be compared with the extant genera of Araceae, subfamily Lasioideae, on the basis of external seed morphology of 22 taxa. Keratosperma appears to be a distinct genus among aroids having many shared characters with extant Lasioideae and represents the oldest known member of the lasioid clade.

Abstract: The natural vegetation of Papua New Guinea is extremely diverse, with many different plant communities occupying the varied terrain of coastal Strandlines and flats, lowland riverine and mountain swamps, drier plains, and moister foothills and mountain slopes (Paijmans 1976). Altogether 1465 plant genera (in 246 families) of widespread tropical, Malesian and Australian affinities are recorded (van Balgooy 1976) and many of them are used for various purposes by the local inhabitants (Powell 1976). The majority of the 3.4 million people living in New Guinea are subsistence agriculturalists, cultivating in swiddens with long-term fallows, or in particular garden types with specialized features and shortterm, often controlled fallows. As well, they tend plants in natural or semi-natural situations, and gather plant products from the forests, open woodlands, grasslands and swamps.1 A number of their crop plants are considered to have been domesticated in the area (e.g. sugarcane, sago, Cyrtosperma, Australimusa bananas, oil and nut Pandanus species, and the vegetables Saccharum edule, Setaria palmirolia and Rungia klossir, Warner 1962, Barrau 1958, 1959, Simmonds 1959, Yen 1971, in press, Powell 1976, in press), although the staples of most regions are exotic crops originating in areas to the north and northwest (taro, major species of yams, Eumusa bananas; Yen and Wheeler 1968, Burkill 1960, Simmonds 1959), or from America in the case of the sweet

Abstract: The species of four genera of Old World Araceae-Lasiinae are enumerated: Cyrtosperma (11, Malesia and Oceania), Lasia (2, Indomalesia), Podolasia (1, West Malesia), and Lasiomorpha (1, Tropical West Africa). Species of Cyrtosperma are illustrated. Distribution maps are provided. The new combination Urospatha wurdackii is made for the Venezuelan Cyrtosperma wurdackii Bunting. Dracontium spinosum is lectotypified.