Seed dispersal is diverse across the flora landscape. Gravity moves acorns from the top of oak trees to their germination site on the forest floor. Water moves the invasive stilt grass seeds downstream to find a new site to overrun. Wind sends maple samaras “helicoptering” to fertile grounds. The most annoying method of seed dispersal is the act of hitchhiking. This Nine Minute Naturalist will cover plants that use us humans, as well as any other able-bodied creature, to move their seeds across the landscape.

Burdock burs

The largest and most obvious hitchhiker in our landscape is the common burdock. This noxious weed is an import from Europe that loves to send its deep taproot into any full sun environment it can infest. It is commonly found along roadways or sunny trial edges at Wintergreen. This biennial wildflower in the aster family spends its first year as a dense rosette of leaves but grows to heights of 3-6 feet in its second year. This second year of growth is when we are treated to the onslaught of burdock burs. These round burs have sharp hooks that attach themselves to any article of clothing or passing fur it meets. These burs entangle themselves in clothes and hair and have even been known to result in the death of small animals that became overly laden with burs. As a parent of outdoorsy children, entangling them from a child’s hair is memorable experience to say the least.

Virginia stickseed

Another plant that seems intent on infuriating hikers is Virginia stickseed. This skinny biennial plant stands 1-4 feet high and blends into the forest floor inconspicuously. This appearance means those tromping through the forest will have no idea how they became laden with tiny green or brown sticky burs. This plant produces a small round bur covered in Velcro-like prickles. The seeds rest upon thin stems which grow horizontally from the main stem to ensure maximum dispersal onto passing animals or hikers.

Trefoil

Tick trefoil is an additional bane of outdoor enthusiasts and dog owners alike. There are many members of the Desmodium family in Virginia. They all feature the hitchhiker seed dispersal methodology. This native member of the pea family produces fruit pods segmented 3-5 times containing kidney shaped seeds. The seeds are covered with fine, hooked hairs that stick to passing animals and hikers with great efficiency.

Bidens

The plants of the genus Bidens are all proficient users of the hitchhiker seed dispersal methodology. These members of the aster family are commonly called tickseeds and their seeds are called beggar-ticks. The seeds are slender, two-pronged seeds that are perfect for hooking into clothing or fur. These plants populate the edge habitat and openings commonly used by humans and animals. On the positive note, compared to Virginia stickseed or burdock, the removal of these beggar-ticks is substantially easier.

Crossing paths with these plants is inevitable for outdoor enthusiasts this time of year. Each time afield is yet another opportunity to transport seed for these hitchhiker plants. Take time to learn a bit about their appearances and you just might save yourself a bit of time picking through your clothes after each hike. Assisting your four-legged friends in avoiding these plants is your impossible task to complete.