Studies on the Gymnantheminae (Vernonieae: Asteraceae) III: restoration of the genus Strobocalyx and the new genus Tarlmounia

—The genus Strobocalyx is resurrected from the synonymy of Gymnanthemum and Vernonia, and the genus Tarlmounia is described. Both of these Asian and Malaysian genera have distinct stylar nodes, blunt stylar hairs and specialized tricolporate, echinate pollen. Strobocalyx is typified by the Asian and Indonesian S. arborea, and combinations are provided for the 6 other East Asian and Malaysian species: Vernonia bockiana, V. chunii, V. esculenta, V. solanifolia, V. sylvatica and V. vidalii. Tarlmounia contains only Vernonia elliptica. A continuing series of papers by the senior author during the last quarter century has segregated many reasonably phyletic units from the old, traditional, aphyletic, core genus Vernonia Schreb. and its relatives. The series was summarized up to a point in two papers, Robinson (1999a), making an initial effort at reorganizing genera of the Eastern Hemisphere Vernonieae, and Robinson (1999b), dealing in more detail with Western Hemisphere members of the tribe. The work is also broadly summarized in less detail in Robinson (2007). These treatments were all based on phenetic studies made prior to the use of DNA sequence data. Partly because of these molecular data, further evaluations of some larger genera have begun. The present series continues to deal with the shrubby or arborescent Gymnanthemum Cass. in the subtribe Gymnantheminae sensu Robinson (1999a), with its woody habit and usually imbricated involucre with rather deciduous inner bracts. The first of these latest studies resurrected the Asiatic genus Monosis DC. in Wight (Robinson & Skvarla 2006) which was distinct in its leaf shape and its lophate pollen. This was only a first step in correcting the overly broad concept of Gymnanthemum. The present study and a simultaneous study of the somewhat similar Asian and Malaysian genus Decaneuropsis (Robinson & Skvarla, 2007) further refine the group. The present paper deals with the groups that include two Southeast Asian species for which Keeley et al. (2007) have obtained DNA sequences, Vernonia arborea Buch.-Ham., a large tree (Fig. 1), and the type of the genus Strobocalyx (Blume in DC.) Spach., and Vernonia elliptica DC. in Wight, a straggling shrub or sprawling vine. The sequences indicate that the two species are rather close to * Corresponding author. PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON 121(1):19–33. 2008.