Abstract Detail

Systematics Section / ASPT

Kathriarachchi, Hashendra [1], Hoffmann, Petra [4], Samuel, Rosabelle [1], Wurdack, J.Kenneth [2], Chase, Mark W. [3].

Molecular phylogenetics of Phyllanthaceae: Evidence from plastid atpB, matK, ndhF, rbcL and single-copy nuclear PHYC sequences.

Phyllanthaceaeis a pantropical family (c. 2000 species) whose circumscription (sensu APG) is believed to be coincident with subfamily Phyllanthoideae of Euphorbiaceae sensu lato. A phylogenetic study of the family using DNA sequence data has delivered congruent results from the plastid genes atpB, matK, ndhF, rbcL and the single-copy nuclear gene PHYC. Our various analyses include sampling from more than 50 of 57 genera, representing all tribes of Phyllanthoideae (Euphorbiaceae sensu lato. The family falls into two major clades that could be recognized at subfamilial level, characterized by inflorescence and leaf anatomical features. Several traditional groupings were retrieved with minor modifications, but most clades found in the molecular studies are considerably different. Floral morphology is highly homoplasious whereas pollen and seed characters agree well with our results. Most notably, the enigmatic genus Dicoelia (previously aberrant in Euphorbiaceae sensu stricto, or sometimes considered close to Pandaceae) and the geographically disjunct genus Lingelsheimia (= Aerisilvaea = Danguyodrypetes; included in tribe Drypeteae = family Putranjivaceae sensu APG) are shown to be embedded in Phyllanthaceae. The taxonomic status of Chorisandrachne (presently a synonym of Leptopus) and the debated placement of Andrachne ovalis have also been clarified. Inclusion of additional taxa confirms paraphyly of Cleistanthus and Phyllanthus, each having three other genera embedded. As a consequence, a new tribal and generic classification of Phyllanthaceae is needed. All six major clades that could be recognized at tribal rank have pantropical distributions.

1 - University of Vienna, Institute for Botany, Dept. of Higher Plant Systematics and Evolution, Rennweg 14, Vienna, A-1030, Austria
2 - Smithsonian Museum Support Centre, Laboratories of Analytical Biology, 4210 Silver Hill Road, Suitland, Maryland, 20746, USA
3 - Royal Botanic Gardens, Kew, Jodrell Laboratory, Richmond, Surrey, TW9 3AB, UK
4 - Royal Botanic Gardens, Kew, Herbarium, Richmond, Surrey, TW9 3AB, U.K.

Keywords:
molecular systematics
Phyllanthaceae
atpB
matK
ndhF
rbcL
PHYC.

Presentation Type: Paper
Session: 30-3
Location: Cottonwood B (Snowbird Center)
Date: Tuesday, August 3rd, 2004
Time: 8:45 AM
Abstract ID:98