From Plant Press, Vol. 24, No. 2, April 2021.
By Julia Beros.
Here is a new lawn of grass; which means here also are clovers and violets, arabidopsis, interloping purslane, a line of cherry trees, stalky earthbound lamiales, some broadleaf plantains, sagewort, and some type of vetch. “My brother operates that type of crane at his job,” he begins as he points across the grassy lawn to fields of industry, spotted with clusters of these cranes sprouting upward as they lattice the sky with their branching arms appointed with yellow hooks that sway gently in the wind. The points hang downward like the achened barb awns of Bidens bidentoides, burrs ready to claw their way into a new spot of dirt.
“He once saw a new guy lift a shipping container up for the first time,” the story continues, “but he forgot to lock it properly and it tipped in the air. One by one, brand new BMW cars came sprinkling out.” He bobs his head in dismay at the very story he has surely told before and continues on his walk around the park leaving our conversation as seamlessly as he entered. I look out to the edge of the bike path and watch the waves of the Delaware River like pleats unfolding as they enter New Jersey. Now the site of a 5-acre green space and playground, Cooper’s Poynt park in Camden, was once the site of a jail, and before then a site of growing industry in a push to increase the use of these ports. And before that this was the site where Elias Diffenbaugh plucked a branching cluster of yellow-topped Bidens bidentoides just before their achenes could sprinkle to the ground. While on site installing a public art piece invoking the history of the changing ports and illegal industrial dumping, attracting the attention of park-goers and passersby, I wondered too about the ecological history of this site defined by urbanization: how has this landscape been defined by botany?
“Beggarticks,” or just Bidens, is an estuarine composite genus with a wide temperate and tropical global distribution. Bidens bidentoides is an increasingly rare species confined to just a straggling few pockets of tidal marsh in the Northeastern United States: the Delaware estuary, the Hudson estuary, and (somewhat debatably) the Chesapeake estuary. In a genus with a diversity described as “chaotic,” B. bidentoides itself made its way through three name revisions, described first by Nuttall as Diodonta bidentoides, then revised as Coreopsis by Torrey and Gray, and finally landing in Bidens under Britton’s description. A plant that grows in mostly disturbed areas, often observed growing among detritus and decaying wood, this species is distinguished from other local ones by its lack of ray florets, simple lanceolate leaves, and antrorsley barbed awns (Smith 2014). As its seed dispersal is adapted to local diffusion near the parent plant, B. bidentoides’ greatest threat is habitat destruction. Clusters of remaining plants remain isolated from each other as well, diminishing the gene diversity which could heighten the vulnerability of this species to extirpation.