Deciduous or evergreen shrubs, sometimes scrambling or climbing by twiggy stems. Leaves simple; blades serrate or entire, secondary veins 3 or 5 from the base. Inflorescence of terminal racemes or panicles, 3-flowered clusters, or flowers solitary. Flowers usually fragrant, petals usually white. Seeds numerous. Derivation of name: after King Ptolemy Philadelphus of the 3rd century BC. Worldwide: About 75 species, widely distributed in the northern hemisphere from temperate Europe, Asia and North America. A few species extend to mountainous habitats in the tropics of Central America and Asia. Zimbabwe: 1 cultivated taxon. |