Milkwort Family

Trees, shrubs, vines and herbs, rarely parasitic. Leaves mostly alternate, simple, entire; stipules usually absent. Flower clusters solitary or in spikes, racemes or branched. Flowers bisexual, irregular, each with a bract and 2 bracteoles. Sepals mostly 5, occasionally the lower 2 united at the base, or the inner 2 (lateral) large and petal-like. Petals 5 but mostly reduced to 3 (2 upper and 1 lower), the lower usually with a fringe. Stamens in 2 groups of 4, or 10, or 3-7, usually united at the base with the petals, the filaments fused to form a split sheath; anthers opening by an apical pore. Ovary superior, of 2(-5) carpels with a single pendulous axile ovule in each. Fruit a nut, samara, drupe or loculicidal capsule.

Rarely grown species include 2 species of the native Comesperma: C. ericinum DC. from E Australia, a variable shrub to 1 m or so tall with oblong to linear leaves to 2.5 cm long, and purple to lilac or white flowers; and C. volubile Labill., a climber with few leaves and purplish to pink or white flowers.

About 18 genera and 950 species (about half in the genus Polygala), cosmopolitan except for the W Pacific, notably New Zealand. Australia has 4 genera and about 40 species.

Occasionally used for local medicines, notably the snake-bite cure of Snake-root, Polygala senega; some species produce dyes; P. butyracea is a source of fibre.

Generally recognised by the petaloid wing-like sepals and 3 petals, the lower one fringed. The flowers are superficially similar to those of the Fabaceae but the families are unrelated; the Fabaceae has stipulate leaves and an ovary with a single carpel.

Source: Spencer, R. (2002). Polygalaceae. In: Spencer, R.. Horticultural Flora of South-eastern Australia. Volume 3. Flowering plants. Dicotyledons. Part 2. The identification of garden and cultivated plants. University of New South Wales Press.

Hero image
kingdom Plantae
phylum   Tracheophyta
class    Magnoliopsida
superorder     Rosanae
order      Fabales
Higher taxa
Subordinate taxa
genus        Polygala L.