VALERIANACEAE Valerian Family | Originally described by Linnaeus (1754), Valerianaceae is traditionally subdivided into three tribes - 1) Patrinieae, 2) Triplostegieae, and 3) Valerianeae. Many authors recognize 14 genera; two in the tribe Patrinieae, a single genus (Triplostegia) in the tribe Triplostegieae, and 11 genera assigned to five subtribes in the Valerianeae. Valerianaceae has long been thought to represent a natural group of ca. 350 species distributed throughout much of the world, with the exception of Australia and New Zealand.
The group is characterized by a) sympetalous, asymmetric flowers, b) inferior, three-carpelate ovaries, c) one fertile carpel with a single anatropous ovule, d) an achene fruit type, and e) lack of endosperm in the ripe seed (with the exception of Triplostegia). The presence of iridoids of the Valepotriate type in many of the species, including Triplostegia, is also characteristic of the group. Although the group appears to have a center of origin in Asia, the majority of the species occur in the Andes of South America. Within Valerianaceae there is a degree of differentiation/specialization in flower and fruit morphology. The most noticeable difference in floral morphologies across Valerianaceae is in the number of stamens, which varies from four to one [five stamens have also been reported in Patrinia]. The trend in the group is toward the reduction in the number of stamens. |
