Spanish Needles

Bidens pilosa

Spanish Needles, Bidens pilosa, photo © by Michael Plagens

A head of mature seeds, ready to be dispersed, of Spanish Needles. Photographed in a small corn field near Eldoret, Rift Valley Province, Kenya. 14 October 2010.

a flowering head of spanish needles, Bidens pilosa Two barbed spurs at the corners of the flattened seeds have served to carry this weedy annual from its original home in tropical America to most places in the tropics and subtropics around the World. In the photo at left about 30 mature seeds each represent what was a single small flower or floret. The florets and thus the seeds are grouped together in a compact head. The florets were of two types in the composite head: rays displaying a white strap-like petal, and yellow disc florets with five, very short petals. The size and number of the white rays vary considerably between populations of Bidens pilosa; sometimes no rays are apparent. In Kenya Spanish Needles is an important weed in farms and gardens where it has a major detrimental impact on crop yields, but they are a source of nectar for butterflies. A Chief at Kakamega, below.

Chief Butterfly, Amauris echeria, from Kakamega, Kenya. Photo © by Michael Plagens

Asteraceae -- Sunflower Family

More Information:

Kenya Natural History

Copyright Michael J. Plagens, page created 17 Nov. 2010, updated 17 March 2017