Javan Cucumber Seeds and Biomimetics

As a child, I watched what we called helicopter leaves (maple tree seeds) spinning to the ground. Sometimes they were plentiful, so other kids and I would scoop them up and fling them in the air, watching them spin down again. Do kids play with Javan cucumber seeds?

The Javan cucumber is misnamed, more closely related to the pumpkin. It is not edible and seems to live to reproduce. Gourds swell and get quite large. When conditions are right, they open up and release the seeds. The seeds are also large and can travel surprising distances.

Alsomitra macrocarpa seed, Wikimedia Commons / Scott Zona (CC BY 2.0)

While birds, insects, and flying mammals are the obvious choices for studies related to flight, these seeds have garnered a great deal of attention over the years for biomimetics (applying things found in nature for human applications). The seeds have inspired several aircraft designs. In addition, wind currents around the gourds that take the seeds on their journeys are also studied. Natural selection may have played a part in these designs, but the specified complexities testify to the work of the Master Engineer. Evolution need not apply.

Aviators have long looked to nature, especially birds, for inspiration. Less well known is aeronautic inspiration gleaned from the plant world. Specifically, the seeds of Alsomitra macrocarpa (previously Zanonia), or Javan cucumber. This is a gourd-producing vine in the squash family that grows in SE Asian tropical forests (fig. 1). Its winged seeds (such structures in general are known as samaras) have been described as the “supreme flyers among seeds”. Most samaras use rotation to slow their descent, but Javan cucumber seeds glide. The vine climbs some five metres (17 ft) into the rainforest canopy, and produces gourds (fruit) about 30 cm (1 ft) in diameter (fig. 2).

The rest of this very interesting article is located at "Flying super-seeds." I still pause on occasion and watch the much smaller maple samaras spin.