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Family Apocynaceae — Dogbane Family

Distinguishing Characters

  1. twining or erect herbs, shrubs or trees ;
  2. leaves usually opposite or whorled, entire with latex;
  3. flowers regular, hypogynous;
  4. calyx 5, united;
  5. corolla 5, united ;
  6. stamens 5, epipetalous ;
  7. carpels 2, superior, united by styles only;
  8. fruit of two follic­les or berry ;
  9. seeds with crown of long silky hairs



General Characters

Vegetative Characters

Habit:

Herbs, shrubs vines and lianas with latex, rarely trees. Laticiferous (with milky latex). Usually  climbing , mostly stem twiners (with hooks);

Root:

Tap-Root, branched

Stem:

Herba­ceous, woody or climbing with latex and bicollateral bundles.

Leaf:

 Leaves evergreen; alternate, or opposite, or whorled; when whorled 3 per whorl; herbaceous or leathery; simple. Lamina entire; pinnately veined. Leaves exstipulate or rarely stipulate.

Floral Characters

Inflorescence:

Cymose, sometimes corymbose, umbellate.

Flower:

Regular, bisexual, hypogynous, actinomorphic, 4-5-merous, often with corona.

Calyx:

5 sepals, rarely 4, divided almost to the base quinconical, imbricate, often with glands.

Corolla:

Petals 5, gamopetalous, rarely 4, sometimes absent, tubular salver-or funnel- shaped, twisted, rarely valvate ; the tbroat or interior of the tube often with hairy scales or other outgrowths (corona).

Androecium:

Stamens 4 to 5, epipetalous. free or filaments rarely united ; anthers oblong-linear or arrow-shaped, usually connate around the stigma and apparently adnate to it, dehiscence longitudinal ; ring-like or glandular disc present.

Gynoecium:

Carpels 2, free below and united by styles only or completely united, superior,partly inferior (Plumeria), when apocarpous, each ovary is 1-celled with marginal placentation, but when syncarpous the ovary may be l-celled with parietal placentation, or 2-celled with axile placentation ; ovules 2- in each cell ; style usually simple, thickened above into a (dumb-bell shaped) stigmatic head which is receptive.

Fruit:

A dry or fleshy drupe, berry, follicle or samara.

Seeds:

Often hairy or winged, endospermic.

Floral Formula of Apocyanaceae

Common Plants (Important Genera)

  1. Nerium (From the Greek name of the oleander, N. oleander derived from neros, damp, humid referring to the habitat of the plant) Nerium odorum (Indian oleander) and N. oleander, oleander vern. Kaner. Cultivated as decorative plants. Introduced- in India from Persia ; leaves verticillate in whorls of three ; flowers rose-coloured, sweet-scented and conspicuous, extremely poisonous.
  2. Vinca. Vinca rosea (Periwinkle-Sadabahar) A cultivated decorative herb, which flowers throughout the year.
  3. Plumeria. Plumeria acuiifolia (Temple or Pagoda Tree). Commonly cultivated for its white fragrant flowers, which are used for garlands. Introduced in India from Tropical America. Leaves and bark have medicinal value.

 

Plants of the family in the Pakflora database

Catharanthus roseus

Nerium oleander

Plumeria rubra

Rhazya stricta

Cascabela thevetia

Plumeria obtusa