Dating dispersal and radiation in the gymnosperm gnetum

As with Ephedra and Welwitschia , Gnetum is pollinated by insects.

Several features suggest this: pollen is not produced in large volumes; both male and female strobili are aromatic (the odor varying with species from sweetish to putrid); and strobili typically open in the morning, or in some species in the evening.

dating dispersal and radiation in the gymnosperm gnetum-29

The genus has been subdivided by Markgraf (1930, in Carlquist 1996b ) as follows: About 19 species of Asian and Indomalesian lianas, incl. Seeds drupelike, enclosed in a red, orange, or yellow, fleshy (rarely corky) false seed coat; female gametophyte tissue copious, succulent. The following species are found in Malesia or SE Asia ( Carlquist 1996b ): Gnetum costatum, G. Gnetum ridleyi Gamble is restricted to a small area in Pahang, Malaysia (Markgraf 1930, in Carlquist 1996b ). gnemon , and as the remaining species of the genus are all woody vines, they are presumably not usable in dendrochronology. "Lignans are of the guaiacyl-syringyl-type; the antiasthmatic properties for which G. The mechanism of such horizontal gene transfer remains unknown, but Won and Renner (2003) state that "agents that have been implied are viruses, bacteria, fungi, and plant cell-piercing insects," all of which have been implicated in other instances of horizontal gene transfer. Gnetum leptostachyum Blume and Gnetum montanum Markgraf are listed as threatened in Viet Nam by the World Conservation Monitoring Centre . The mountain is an isolated volcano south of the Central Divide. Conspectus Regni Vegetabilis: Secundum Characteres Morphologicos Praesertim Carpicos in Classes Ordines et Famillas Digesti , p. Proceedings of the National Academy of Science 100(19):10824-10829.

Horizontal gene transfer from flowering plant to Gnetum. Vegetative propagation of Gnetum africanum Welw., a leafy vegetable from West Africa. A new Permian gnetalean cone as fossil evidence for supporting current molecular phylogeny. Please send feedback and corrections directly to the source. Both male and female megastrobili terminal or lateral, sometimes arranged in dense, cauliflorous clusters on old stems. Gnetum arboreum Foxworthy is restricted to a small portion of Luzon, Philippines (Markgraf 1930, in Carlquist 1996b ). See original regarding copyrights and terms of use. Each megastrobilus consists of a straight axis above a basal pair of opposite, connate bracts; the axis bears usually three to six superposed cupules, each of which contains several to many male or female strobili. Gnetum contractum Markgraf is found in Travancore, India (Markgraf 1930, in Carlquist 1996b ). We parsed the following live from the Web into this page. Dioecious, evergreen, mostly woody vines, rarely shrubs or trees; stems with swollen nodes.