For this Plant of the Week post, I focused on a plant family, rather than a single species. The winter structure this family brings is crucial to the overall feel of a Piet Oudolf garden in winter. As the largest dicot family with over 23,000 species of herbs, shrubs, and trees with an almost worldwide distribution, it is fair to say everyone will be familiar with at least some of these plants.
I am of course speaking about the aster family, Asteraceae. Although not found growing on the High Line, the poster child for this plant family is the sunflower, Helianthus annuus. While we tend to think of the sunflower and other Asteraceae plants as being a single flower, they are in fact many flowers made up of outer unfertile ray flowers and hundreds of fertile disk flowers in the center. The ray flowers serve no reproductive function other than to attract insects for pollination. The ovaries sit on the receptacle in the center, below the attachment of the corolla and stamens. When the inflorescence ripens, it can contain 1,500 achenes. The flowers of many Astereceae plants are also heliotropic, having the ability to track the sun as it moves from east to west.
This family features many genera of our herbaceous perennials that bring color and variation to the High Line during the year: the showy pinks and whites of Echinacea; yellows of Silphium, Solidago, and Rudbeckia; rich burgundy reds of Helenium; the fall brilliance of purples from Symphyotrichum. A favorite of mine is the deep lavender and yellow of the Japanese native Aster tataricus 'Jindai', now the only Old World genus aster found on the High Line after the most recent genus reclassification.
Long after the abundant flowers have faded leaving behind dry seed heads and stalks, these plants become the "bones" of the garden with contrasts in shape, color, size, and texture. Sharp imbricated bracts hang from large, globe-shaped seed heads on Echinacea pallida, while fragile withered ray flowers hang on to tiny button discs on Symphyotrichum laeve 'Bluebird'. A snow flurry only makes the features of the Asteraceae family more pronounced.
It is a pleasing thing to be able to freely recognize a plant family at any time of year, however there is something more satisfying about recognizing plants you know in the winter. I encourage anyone who has enjoyed the High Line during the year to come and see how many of these wonderful plants they can recognize for themselves this time of year.
Members of the Asteraceae family are cosmopolitan and can be found growing in a variety of site conditions, from moist, humus-rich woodland edges to sunny grasslands, roadsides, ditches and other disturbed sites. Many are fairly drought-tolerant, prefer at least partial sunlight, with many preferring full sun. Here on the High Line they perform well, even in some of our less hospitable microclimates.
WHERE TO FIND THESE PLANTS:
Examples of the Asteraceae family plants can be found in each garden on the High Line, from Gansevoort St. to 34th St.
TD Bank is the Presenting Green Sponsor of the High Line.