The Polygalaceae or the milkwort family are made up of flowering plants in the order Fabales. They have a near-cosmopolitan range, with about 27 genera and ca. 900 known species of herbs, shrubs and trees. Over half of the species are in one genus, Polygala, the milkworts.
The family was first described in 1809 by Johann Hoffmansegg and Johann Link. In 1896, Robert Chodat split it into three tribes. A fourth tribe was split off from the tribe Polygaleae in 1992. Under the Cronquist classification system, Polygalaceae were treated in a separate order of their own, Polygalales. Currently, according to the Angiosperm Phylogeny Group, the family belongs in Fabales.
Description Polygalaceae are annual or perennial herbs, shrubs, trees or lianas. Its zygomorphic, hermaphrodite, bisexual flowers have three to five petals and five sepals. Its leaves are usually alternate, but may be opposite, fascicled, or verticillate. Each flower usually contains eight stamens, though this may range from three to ten. They are usually in two series. The fruits of each plant can be a capsule, samara, or drupe.
Tribes and genera The Polygalaceae comprise the following genera, with tribes based on various sources.
Carpolobieae Eriksen Atroxima Stapf Carpolobia G. Don Moutabeae Chodat Barnhartia Gleason Diclidanthera Mart. Eriandra P. Royen & Steenis Moutabea Aubl. Polygaleae Chodat Acanthocladus Klotzsch ex Hassk. Ancylotropis Asemeia Raf. Badiera DC. Bredemeyera Willd. Caamembeca J.F.B. Pastore Chamaebuxus (synonym Polygaloides Haller) Comesperma Labill. Epirixanthes Blume Gymnospora (Chodat) J.F.B.Pastore Hebecarpa (Chodat) J.R.Abbott Heterosamara Kuntze Hualania Phil. Monnina Ruiz & Pav. Monrosia Grondona Muraltia DC. Phlebotaenia Griseb. Polygala L. Rhamphopetalum J.F.B.Pastore & M.Mota Rhinotropis (S.F. Blake) J.R. Abbott Salomonia Lour. Securidaca L. Senega (DC.) Spach Xanthophylleae Chodat Xanthophyllum Roxb.
Fossils †Deviacer Manchester †Paleosecuridaca Pigg, Kathleen B., M.L. DeVore & M.F. Wojc. 2008
Systematics Modern molecular phylogenetics suggest the following relationships:
References