Three new of () from

Henrik LANTZ Department of Phanerogamic Botany, Swedish Museum of Natural History, SE-104 05 Stockholm (Sweden) and Department of Systematic Botany, Uppsala University, SE-752 36 Uppsala (Sweden) [email protected]

Jens KLACKENBERG Department of Phanerogamic Botany, Swedish Museum of Natural History, SE-104 05 Stockholm (Sweden) [email protected]

Sylvain RAZAFIMANDIMBISON The Bergius Foundation at the Royal Swedish Academy of Sciences, SE-104 05 Stockholm (Sweden), and Department of Botany, Bergius Foundation, Stockholm University, SE-106 91 Stockholm (Sweden) sylvain.razafi [email protected]

Arnaud MOULY Muséum national d'Histoire naturelle, Département Systématique et Évolution, Herbier national, UMS 2700 CNRS, USM 0602, case postale 39, 57 rue Cuvier, F-75231 Paris cedex 05 (France) [email protected]

Lantz H., Klackenberg J., Razafi mandimbison S. & Mouly A. 2007. — Three new species of Vanguerieae (Rubiaceae) from Madagascar. Adansonia, sér. 3, 29 (1) : 129-136.

ABSTRACT Th ree new species of the tribe Vanguerieae (Rubiaceae) from Madagascar are KEY WORDS Rubiaceae, described with illustrations. Two species are placed in Pyrostria, one in Peponi- Vanguerieae, dium. Peponidium crassifolium is recognized by its thick and slightly succulent Peponidium, leaves, Pyrostria pendula by the pendulous fl owers and persistent pedicels, and Pyrostria, Madagascar, Pyrostria serpentina by a serpentine habit and small leaves. Th e morphology and new species. taxonomic history of the dioecious genera of the tribe are discussed.

ADANSONIA, sér. 3 • 2007 • 29 (1) © Publications Scientifi ques du Muséum national d’Histoire naturelle, Paris. www.adansonia.com 129 Lantz H. et al.

RÉSUMÉ Trois nouvelles espèces de Vanguerieae (Rubiaceae) de Madagascar. Trois nouvelles espèces de la tribu des Vanguerieae (Rubiaceae) de Madagascar sont décrites et illustrées. Deux espèces sont placées dans le genre Pyrostria et une troisième est attribuée à Peponidium. Peponidium crassifolium se distingue MOTS CLÉS Rubiaceae, des autres espèces du genre par ses feuilles épaisses et légèrement succulentes, Vanguerieae, Pyrostria pendula se caractérise par ses fl eurs pendantes et ses pédicelles persis- Peponidium, tants, et Pyrostria serpentina se diff érencie dans le genre par son port sinueux et Pyrostria, Madagascar, ses petites feuilles. La morphologie et l’histoire taxinomique des genres dioïques espèces nouvelles. de la tribu sont discutées.

INTRODUCTION of axillary infl orescences paired at the nodes, valvate aestivation, and a unique type of pollen presenter Vanguerieae is a tribe of around 600 species notori- (Igersheim 1993) on the apex of the style makes ous for its diffi cult generic circumscriptions (e.g., the tribe easy to recognize. Th e majority of the Bridson 1992). Th is situation was in part recently species found in Madagascar are members of the improved by the presentation of a new classifi cation “dioecious group” (Lantz & Bremer 2004), an in- of the large genera Lam. and Vangueria formal name for a monophyletic clade of species, Juss. based on combined molecular-morphological in which most taxa are dioecious. Th e dioecious and combined molecular studies (Lantz & Bremer species are heteromorphic with a variation in the 2004, 2005, respectively). Nevertheless, several number of fl owers per infl orescence and number of genera remain little studied and in particular some corolla lobes. Th e most common situation is that geographic regions need to be investigated further. male individuals have fasciculate infl orescences Vanguerieae is distributed in sub-Saharan , with comparably more fl owers (> 2) and in some