Notice: Atrium is currently undergoing maintenance. During this time, some or all images may not be displayed.

Family: Apocynaceae Juss.

Kingdom: Plantae Rank: Family Parent: Gentianales Status: Valid

Common Names:

  • OLEANDER FAMILY - English, United States of America
  • DOGBANE FAMILY - English, United States of America

Morphological Description

Family Recognition in the Field: Herbs or vines with simple, entire, often opposite leaves, milky sap, sympetalous corollas usually with a distinct tube, and 2 pistils united only by their styles and/or stigmas. Similar to Asclepiadaceae (e.g., herbs or vines with milky sap) but that family has flowers with a distinctive corona and a gynostegium (= combined structure composed of stamens and pistils).

Diagnosis: Ours perennial herbs or vines with milky juice; leaves opposite or whorled (except alternate in Amsonia), sessile or very short-petioled, simple, entire, deciduous or evergreen; flowers axillary or terminal, solitary or in cymes; sepals 5, barely united at base; corollas salverform, funnelform, campanulate, cylindric, or urceolate, with 5 lobes, the throat or summit of tube usually with a constriction, crown, or dense zone of hairs; stamens 5, separate; pollen not in pollinia; pistils 2, united by styles and/or stigmas only (superficially flowers can appear to have 2 separate pistils); ovaries superior; fruit of 2 (or 1 by abortion) follicles (or in other areas berries or drupes).

Other

Ecology: Some species are poisonous in nature.

Notes: A medium-large (1,900 species in 165 genera), pantropical family with some temperate species; vegetatively it includes mainly lianas, trees, shrubs, and a few temperate herbs; they have ubiquitous laticifer systems, glycosides, and alkaloids. The family contains many ornamental, poisonous, and medicinal species including the beautiful Plumeria rubra L. (FRANGIPANI), the widely planted but very poisonous Nerium oleander L. (OLEANDER), Rauvolfia serpentina (L.) Kurz, the source of the medicinal alkaloid reserpine, Acokanthera species, from which deadly arrow poisons (cardiac glycosides including ouabain with an effect like digitalin) are obtained in Africa, Strophanthus, an Old World genus yielding arrow poisons and the cardiac drug strophanthin, and Catharanthus, the source of alkaloids used in cancer treatments. OLEANDER, a commonly used ornamental, contains extremely poisonous cardiac glycosides (e.g., neriin and oleandrin) resembling digitalin in action; a single leaf can kill an adult; children have been poisoned by sucking nectar or chewing leaves; poisoning may result from using twigs as skewers for food or even inhaling the smoke; even water in which flowers have been placed is toxic (Schmutz & Hamilton 1979; Morton 1982; Powell 1988). The sap of all species should be avoided. Apocynaceae are closely related to Asclepiadaceae (MILKWEED family) and considered paraphyletic when treated separately (Judd et al. 1994); Liede (1997), for example, treated the asclepiads as subfamily Asclepiadoideae in the Apocynaceae. From a cladistic standpoint the two should be lumped to form a more inclusive monophyletic Apocynaceae (Judd et al. 1994). (subclass Asteridae)