PEI’s wild plants have all sorts of innovative ways to disperse their seeds. Some use wind, others water, and a rare few go with ballistic propulsion. Today’s plant is one of the most effective I know at spreading its seeds via animals, including humans. This is the well-named Nodding Beggar’s-tick (Bidens cernua).
Nodding Beggar’s-tick is a common, native member of the Aster Family (Asteraceae) with beautiful golden-yellow flowers in late summer (Photo 1). It likes damp ground, and can be found along the edges of ponds, freshwater marshes, and slow-moving streams across the Island. As flowers mature and develop seeds, the heads droop giving this plant the ‘nodding’ part of its name (Photo 2).
Another common name for this plant is ‘Sticktight’ and if you touch those seed heads, you’ll quickly understand why! Each seed is covered in tiny, barbed hooks and – as if that weren’t enough – has four larger teeth at one end that are themselves covered in hooks. This adaptation allows the seeds to attach to any passing animal, whether it has fur, feathers, or smooth skin (Photo 3). It’s been said that these seeds will stick to you like ticks, hence the name ‘Beggar’s-tick’.
Nodding Beggar’s-tick is an annual, and it’s not uncommon to find it popping up in a spot where you’ve never seen it before. While the sticky seeds may be annoying, they are easy to remove from skin, or brush out of fur or hair (far easier than Burdocks or the Woodland Agrimony I profiled here https://www.pei-untamed.com/post/woodland-agrimony ). They’re also a popular food for songbirds and waterfowl, and the flowers are used by our late season pollinators including bees, butterflies, and moths. If you have a sunny but damp spot on your property, Nodding Beggar’s-tick can be a beautiful and wildlife-friendly native plant addition that’s as easy to add as scattering some seeds. Just be mindful that if you do this and have dogs, they are pretty well guaranteed to get covered in seeds in fall!
While Nodding Beggar’s-tick has mastered the art of co-opting animals into its seed-distribution agenda, it doesn’t rely on them alone. Those light seeds also float, and so are distributed by water when they fall into the ponds and streams along which this plant grows. In some places, you can find extensive patches of this plant, or have a new population pop up well downstream of a previously known spot.
Nodding Beggar’s-tick is a beautiful and extremely well-adapted part of PEI untamed!