The collecting season is short here in New England, and we are nearly done with our quota (182 of 200 collections to date). We have noticed a distinct pattern in the dominance of the species we have collected based on their abundance and phenology: Back in July and the first half of August, we were mostly collecting the saltmarsh blackgrass (Juncus gerardii), and from the latter half of August to mid-September we were primarily collecting marshelder (Iva frutescens). For the past four weeks we have been collecting mostly asters, in particular Eupatorium sp. sensu lato and Solidago sp. These are all wind-dispersed seeds that are easy to collect, usually later in the season. Unfortunately, many of the species we collect from both look incredibly similar and grow together, especially in the case of the Solidago species, of which we have collected four thus far (S. altissima, S. canadensis, S. sempervirens, and S. rugosa). For example, S. altissima and S. canadensis look identical, except that S. altissima has an evenly hairy abaxial leaf surface and stem, whereas S. canadensis has hairs only on the midveins, with the rest of the abaxial lamina and stem completely glabrous. On paper this seems diagnostic, but of course, Nature has given us individuals that look intermediate between the two (e.g., very sparsely hairy on the abaxial leaf lamina and stem) and we have to make do between our trusty Flora Novae Angliae key and our best understanding of goldenrod gestalt.
Tall goldenrod (Solidago altissima), Grape Island, Boston Harbor Islands National Recreation Area, MA
We have also made some great collections of species that once were all lumped in the Eupatorium genus. Of those we have collected, most are now in the Eutrochium genus, e.g., E. dubium and E. maculatum., but the boneset (Eupatorium perfoliatum) has remained in the old genus. All these species tend to grow very large floral heads and make for superb seed collections.
Boneset (Eupatorium perfoliatum), Harwich, MA
With much of our work now focused on wind-dispersed seed (Asteraceae and others), we couldn’t help but take advantage of helping Nature out with dispersal too, with these milkweed (Asclepias syriaca) seeds:
