Seed Dispersal of Nerium Oleander

March 30, 2016

Seed dispersal Nerium 16.1.16 wet, seeds waitng to dryness

Photographer: Menashe Davidson
Summary Author: Menashe Davidson

Since plants have limited mobility they rely upon a variety of dispersal vectors to transport their seeds. Wind is perhaps the most important mode of seed dispersal; others include gravity, water and animals. A major consideration for survival success, to reach a favorable habitat, is the need for abundant seed production to maximize the likelihood of a seed landing in a site suitable for germination and growth.

In January of this year I passed a grove of Nerium oleander (family Apocynaceae) trees in Rishon LeZion, Israel, and noticed the seeds shown above. In the Mediterranean region, during the winter season, windy conditions help disperse these seeds and wet soil conditions give them the best chance to germinate. Nerium oleander is cultivated worldwide as an ornamental plant and is native to the Mediterranean region. Their fruit is a long narrow capsule, (4-6 in or 10-15 cm long) that opens to dry, enabling the fluffy seeds to disperse. On this cool January morning, the seed hairs were wet with dew and the seeds stayed inside the open capsule. One hour later, however, seeds exposed to the Sun dried out and were ready for dispersal by the first gust of wind. Photo taken on January 16, 2016.

Photo Details: Camera Model: NIKON D7100; Focal Length: 105mm (35mm equivalent: 157mm); Aperture: ƒ/18.0; Exposure Time: 0.0050 s (1/200); ISO equiv: 1000.