Abstract Detail

Systematics Section/ASPT

Luz, Cintia [1], Pirani, Jose Rubens [2].

Specific circumscription problems and habitat diversity of Schinus sect. Pseudoduvaua Barkley (Anacardiaceae): simple leaved, non-spinescent species from Southern South America (Bolivia, Argentina and Chile).

Schinus is an Anacardiaceae genus comprising ca. 33 species restricted to southern South America. Schinus is divided into S. subg. Euschinus Barkley and Schinus subg. Duvaua (Kunth.) Barkley. The latter is further subdivided into S. sect. Euduvaua Barkley encompassing approximately 12 species with spine-ending branches and S. sect. Pseudoduvaua Barkley with approximately 10 unarmed species. The former section has been subjected of morphological studies (Cabrera 1938, Barkley 1957) as an attempt to clarify their complex species delimitations. Despite those efforts, the present taxonomic work reveals great circumscription problems also within S. sect. Pseudoduvaua. This study aims to evaluate species delimitation of S. sect. Pseudoduvaua based on a virtually complete survey of herbarium collections and analysis of natural populations throughout its distribution. Our preliminary results from a wide sampling study including the type specimens of S. kauselii Barkley and S. montanus (Phil.) Engl. showed that these chilean endemics share coincident distributions and are also morphologically similar except for a few phenotypic variations (e.g. leaf base and habit branching pattern). This approach, focused both on morphology and geographic data, suggests these taxa are likely to be conspecific. Also noteworthy is our broader evaluation of S. velutinus (Turcz.) I.M.Johnst. and S. latifolius (Gillies ex Lindl.) Engl., both endemics of chilean sclerophyll forests under mediterranean climate. Even though these species are usually distinguished by the indumenta (branches and leaves densely covered with trichomes in S. velutinus and glabrous in S. latifolius), during field work we came upon individuals with an intermediate morphology growing among the two previously known morphotypes. Not surprisingly, Engler (1876) has previously considered both taxa as varieties under S. latifolius. In relation to habitat diversity the majority of Schinus species occur in dry forests at temperate, subtropical and tropical areas. Nevertheless the unusual restriction of some species to particularly different habitats can also provide additional evidence for taxa distinctiveness. As an example of this, S. andinus (Engl.) I.M.Johnst., S. gracilipes I.M.Johnst., S. venturii Barkley and S. myrtifolius (Griseb.) Cabrera, are all well circumscribed taxa which are restricted to the moist forests of Argentina and Bolivia. Finally, S. patagonicus (Phil.) I.M.Johnst. grows in transitional environments, between chilean temperate forests and argentinean Patagonia. This study provides evidence that extensive field work observations associated with a wide analysis of specimens available allow the improvement of the taxonomy at specific level as well as helping detection of which groups deserve analyses under more refined methods.

1 - São Paulo University, Botany, Rua do Matão, 277 - Cidade Universitária, Botany, São Paulo, SP, 05508-090, Brasil
2 - São Paulo University, Botany, Rua do Matão, 277 - Cidade Universitária, São Paulo, SP, 05508-090, Brasil

Keywords:
Species delimitation
Dry forests
Moist forests
Temperate forests
Patagonia.

Presentation Type: Poster:Posters for Sections
Session: P
Location: Hall D/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 5:30 PM
Number: PSY026
Abstract ID:1076
Candidate for Awards:None