Spanish Needles, Devil’s Pitchfork, and Bidens alba are one and the same – and humans have bestowed this plant with several other common names. This plant is scientifically known as Bidens alba. “Bidens” refers to the two sharp “teeth” usually found at the tip of each spine associated with a seed. The teeth are sharp and point backward such that an animal that passes by will get “hooked” and carry the seed away until it is pulled off or brushed off – and there a new Bidens plant may grow. The species name “alba” means “white” and refers to its white petals.
This plant is generally well-known and often disliked because it is common and produces seeds that stick to our clothing as we walk by and to our dog’s fur. But this is a native plant – almost certainly originating in South America, but spread widely by humans and animals who unknowingly carried its seeds to new areas. Devil’s Pitchfork and its relatives can now be found in warmer areas around the world. On the positive side Bidens is a major source of nectar for butterflies, bees, and other insects, and the white-petaled yellow-center flowers add a bit of beauty to the landscape by flowering year-round. Bidens can bloom when only a few inches off the ground – and if other plants grow taller around it, Bidens can also grow taller often reaching four feet tall in wet weedy areas areas. Bidens is also useful as a source of food for humans – its leaves make a nice addition to a salad – but be certain of your identification of the plant!
Yes, Bidens is a nuisance if you have to pluck its seeds from your clothes, but it is much too common and resilient to get rid of. Instead, pull it up by the roots where it isn’t wanted, and leave some in a less problematic area for the tremendous diversity of beautiful butterflies that favor it.